What COTS parts would you like to see? [Archive]

Michael Hill

11-05-2016, 18:52

We're at a point of the year where new products are probably being developed by FRC suppliers, so let's give them some ideas of what would help you build a better robot faster.

I'd personally like to see more 3/8" hex power transmission parts (sprockets, belt pulleys, etc.). Vex offers a 3/8" hex miter gear, but no power transmission means other than gears. We really wanted to use them on a 3-direction intake system, but kept hitting roadblocks. We could have gone with a round bore solution, but we went another direction.

I think a lot of us would like 3mm and 5mm pitch GT2 belt hex sprockets, though I understand there are patent issues with that.

What would you like to see?

IronicDeadBird

11-05-2016, 20:34

Everything that is currently being sold but in different colors. I would be interested in seeing if it would relieve some of the parts being bought out.

Billfred

11-05-2016, 21:33

Everything that is currently being sold but in different colors. I would be interested in seeing if it would relieve some of the parts being bought out.

How would different colors fix anything? Unless you had to boost the pre-color production to meet a MOQ, that doesn't change the quantity available (and even then, it creates more SKUs for vendors to have to pore over).

Sperkowsky

11-05-2016, 21:52

A metal versaplanetary cim adaptor.
And
More beefy right angle gussets

s_forbes

11-05-2016, 21:57

Eric Scheuing

11-05-2016, 21:58

Stronger alloy options for gear stages.

Kevin Leonard

11-05-2016, 22:03

ASD20

11-05-2016, 22:06

Hex hubs with less slop. Would a steel version help with this problem?

R.C.

11-05-2016, 22:21

Hex hubs with less slop. Would a steel version help with this problem?

No, steel hubs would not help. This is all dependent on the broach itself. Your best bet is to shim the hub if you want a tighter fit or custom make your hex shaft. Apparently soda cans work really well for shims! Just ask Devin ;)

ASD20

11-05-2016, 22:32

No, steel hubs would not help. This is all dependent on the broach itself. Your best bet is to shim the hub if you want a tighter fit or custom make your hex shaft. Apparently soda cans work really well for shims! Just ask Devin ;)

I'll have to try that. Thanks for the advice.

Derek Bessette

11-05-2016, 22:39

VersaHub (1.125" Bearing Pilot, 3/8" Thick, w/ Plate Sprocket Mount)

daliberator

11-05-2016, 22:53

A metal versaplanetary cim adaptor.
We had a versaplanetary and mini CIM cantilevered in a way that looks a lot like how you guys did it, and at Iowa it broke during an elims match. We didn't have time to redesign the mounting before our next event, so we ended up casting the adapter out of aluminum, and it worked great. It sure would be nice to buy one though :)

thinker&planner

11-05-2016, 23:00

In line with the metal CIM versa adapter, it would be great to have a metal dual-motor input for the versaplanetary too. With the new 775 pro, way too much power can be run through the plastic dual-input stage.

Our team ended up using the same internals and CNCing some really simple replacement housings out of aluminum.

And in general, I would like to see less FRC specific COTS assemblies (like the butterfly drive pod from VEX) because (personal opinion) I don't like the direction that that is headed. More part-level COTS parts (not full assemblies of specialized mechanisms). I really like the idea of an assortment of spacers/standoffs (but McMaster is probably the best option).

-A source for Dark Soul #25 chain breakers.

jkelleyrtp

11-05-2016, 23:02

Mostly spacers, standoffs, and more shaft selection.

Spacers

1/4 Threaded spacer for 1/8" and 1/16" 1x1 and 2x1 Al tube
Delrin spacers for 3/8" hex and 1/2" and 3/8" round

Standoffs

Common standoffs availble through Vex/AM/WCP to save on McMaster orders
Round and hex variants

Shafts

Thunderhex-style 3/8" hex with bore and similar variants for 1/2" and 3/8" round
Some grinding on the thunderhex to improve fit with hex bearings
Perhaps some steel variants of the current thunderhex/bored round shaft

Also, a more robust option for VP encoders. As mentioned above, plastic would be nice, but the boards and wires themselves need some sort of reinforcement.

ASD20

11-05-2016, 23:08

Mostly spacers, standoffs, and more shaft selection.

Spacers

1/4 Threaded spacer for 1/8" and 1/16" 1x1 and 2x1 Al tube
Delrin spacers for 3/8" hex and 1/2" and 3/8" round

VexPro offers an assortment of delrin 3/8 and 1/2 inch hex spacers.
http://www.vexrobotics.com/vexpro/hardware/acetalspacers-vexpro.html

jkelleyrtp

11-05-2016, 23:22

VexPro offers an assortment of delrin 3/8 and 1/2 inch hex spacers.
http://www.vexrobotics.com/vexpro/hardware/acetalspacers-vexpro.html

Whoops, knew about the 1/2" hex but not the 3/8". Guess I'll settle for just the round variants then.

Chak

11-05-2016, 23:24

Whoops, knew about the 1/2" hex but not the 3/8". Guess I'll settle for just the round variants then.

Since they're just spacers, can't you use the hex spacers on round shaft? :)

roboruler

11-05-2016, 23:31

Stronger alloy options for gear stages.

7075-T6 is the best alloy for aluminium gears available.
Yes, perhaps small gears such as those gears up to maybe 24 tooth could have the option of being replaced with drop in 4140 gears.

Chak

11-05-2016, 23:37

7075-T6 is the best alloy for aluminium gears available.
Yes, perhaps small gears such as those gears up to maybe 24 tooth could have the option of being replaced with drop in 4140 gears.

Every broken gear picture on CD has the teeth sheered off. I've never seen the body of a gear crack. So, the failure mode seems to be the teeth. Would 4140 steel gears with lightening holes be an option? How much more would it cost?

asid61

11-05-2016, 23:38

After going through a season thinking "man, I wish we had a -----", I'm totally blanking out.

The tube spacers would be super useful, for sure. That would have saved us a lot of pain this year. Other standoffs would also come in handy.
Totally separate CIM mounting holes on the WCP gearboxes- the CIM bled into the 12t pinion mounting distance from the 14t distance, causing massive friction.
3/8" hex versahubs, however the 3/8" hex to 1/2" hex adapter by WCP solves a lot of 3/8" hex issues.
More GT2 belt pulleys would be great; WCP sells 12t pulleys and belts but not the larger hex broach pulleys we need! Small 12t 5mm HTD pulleys would also be nice.

roboruler

11-05-2016, 23:45

Right angle output stage for the Versa-Planetary gearbox, not an adapter but an integrated output stage that takes the place of the normal output stage.

pilleya

12-05-2016, 00:00

Right angle output stage for the Versa-Planetary gearbox, not an adapter but an integrated output stage that takes the place of the normal output stage.

This would be very useful, depending on the input motor and the reduction there would be significant torque on the bevel gears( if bevel gears were used). It might be difficult to find small enough bevel gears that would be able to take the torque.

How efficient are bevel gears? I've heard worm gears can be quite in-efficient.

I know team 33 made a tutorial on how to modify a versa-planetary and a drill/driver right angle adapter to accomplish this:

http://www.chiefdelphi.com/forums/showthread.php?t=147095&highlight=right+angle

theawesome1730

12-05-2016, 00:06

Cycloid stage in a versa planetary. Couple that with a right angle adapter and you've got a monster of setup to lift arms etc.

jeremylee

12-05-2016, 00:08

VersaBlock with 1/4" drop when flipped allowing drop combinations of the following when mixed with the current 1/8" flipped:

1/16", 1/8", 3/16", 1/4"

Cothron Theiss

12-05-2016, 00:13

1/2" hex bore bevel gears.
I'm sure there are others I could think of, but that's what pops into my mind right now.

AdamHeard

12-05-2016, 00:19

Every broken gear picture on CD has the teeth sheered off. I've never seen the body of a gear crack. So, the failure mode seems to be the teeth. Would 4140 steel gears with lightening holes be an option? How much more would it cost?

The attached gear was pocketed on each side .112, leaving a web thickness of .150.

roboruler

12-05-2016, 00:56

The attached gear was pocketed on each side .112, leaving a web thickness of .150.

That is a 7075-T6 gear isn't it?

Andymark sell a few gears with weight saving holes in, I think in the weight saving your not going to be able to reduce enough weight to make it equal to an un-weight saved Aluminium gear however it would still be great to do some experimentation

Team 254 did some really nice weight saving for the large VEXpro aluminium first stage gear in their CIM-over wheel gearbox, I'm not sure if they had any problems with any gears during the season.

We probably don't want to hi-jack the thread with a Aluminium gear vs steel gear debate :)

Knufire

12-05-2016, 01:01

The attached gear was pocketed on each side .112, leaving a web thickness of .150.

Is the slot to prevent the gear from resonating?

JohnFogarty

12-05-2016, 01:17

A metal versaplanetary cim adaptor.

10/10 would buy.

Oblarg

12-05-2016, 01:19

Clamping hubs and other hardware. I've been waiting for an FRC supplier to do a clamping hub for *years* and, so far, been disappointed.

Munchskull

12-05-2016, 01:25

An electric solenoid for momentary shifting that is packaged for easy swap in use with the vexpro/WCP shifters.

RyanCahoon

12-05-2016, 03:35

1/2" (-0.001") round solid aluminum shaft stock (for less than the 3x mark-up over VexPro that McMaster currently sells it for)

Tottanka

12-05-2016, 05:29

1/2" hex bore bevel gears.
I'm sure there are others I could think of, but that's what pops into my mind right now.

+1.
Also, iv'e been dreaming of a Versaplanetary Worm gearbox sage, with any reduction.

I would also like some improvements in the Ballshifters. (the nuts should be molded in and not put there, they keep falling into the gear and are a nightmare to get out. The CIMs seem to loosen up from time to time. The adapter for the Pancake cylinder should be made out of something more durable).

I would also love it of someone started selling good chain breaking and assembling tools for both 35 and 25.

marshall

12-05-2016, 07:11

messer5740

12-05-2016, 07:35

More avalibity of parts. Many COTS items were sold out or on back order for much of the build season. A great example of this is the pneumatic wheel storage...

jwfoss

12-05-2016, 07:37

-4"x1.5" and 4"x2" Aluminum Wheels with 1/2" Hex Broach
-Anti-backdrive stage for VersaPlanetary
-Disc Brake set up with 1/2" Hex or "Standard" Sprocket Hole Pattern

roboruler

12-05-2016, 07:39

More avalibity of parts. Many COTS items were sold out or on back order for much of the build season. A great example of this is the pneumatic wheel storage...

That is very difficult for suppliers, it is almost a gamble, as they have to buy or fabricate parts in advance, and if they are not useful for a particular season then that is a huge burden on them. A way around it is to get certain suppliers like Andymark and Vex in the loop in terms of the season so they can plan ahead, but it is really not ideal at all.

BoilerMentor

12-05-2016, 08:06

The COTs parts available through Vexpro, AndyMark, and McMaster made all of our design work very easy. I'm glad we have so many parts available now compared to years ago!

One part we end up making a lot of, and isn't easy to do if you are a low resource team with no mill/lathe, is spacer inserts for tubes. These let you do through-bolt connections that can be tightened without crushing the tube, so you actually have a strong bolted joint. For VexPro in particular, spacers like this that fit their Versaframe extrusion sizes could be very useful for some teams.

http://i.imgur.com/6Q6bLww.png

In years past where crushing box was an issue, we would rip down a piece of scrap hardwood on a table saw to fit snugly within a tube and just use that. Does exactly what you're after and would be way easier to position and use than a round spacer. I can see positioning one of those little round spacers and lining it up with the bolt holes being a royal pain, especially if it's deep in a tube that's already attached to the robot.

BrendanB

12-05-2016, 08:14

3/8" hex gears that are slightly thinner. 1/2" hex has been amazing however for some applications you want to use gears but the current hex line from Vexpro just seems overkill and you are throwing extra weight and space where you don't need to.

+1 for a Versatube spacer.

1/2" hex bevel gears. Would have come in handy this year but with only 3/8" available and all of our existing system being 1/2" hex it made it just about impossible to integrate.

After this season, a non plastic dead axle hub for 6" and 8" wheels would be nice but this is mostly game dependent. :rolleyes:

jijiglobe

12-05-2016, 08:29

A mag encoder that's compatible with all the AndyMark gearboxes that take USDigital optical encoders (same mounting geometry and all). 694 has had a bad time with the optical encoders, as the break easily, and can get ruined by dust.

Bkeeneykid

12-05-2016, 08:31

An electric solenoid for momentary shifting that is packaged for easy swap in use with the vexpro/WCP shifters.

I would love this, it seems to be legal. Pneumatic actuators under a 1" stroke are legal, and it's just a matter of getting a correct mounting. I'd imaging if there's a standard size of solenoid actuators, it's just a matter of getting a shroud around it that's the same dimensions as the pancake solenoid from VEX to swap in the ball shifter.

Eric Scheuing

12-05-2016, 08:54

-Anti-backdrive stage for VersaPlanetary
This and the right-angle adapter would be incredibly useful.

7075-T6 is the best alloy for aluminium gears available.What about steel though? Especially with the smaller gears, the weight increase isn't going to be that significant, and if case hardened, I can't imagine you'd see much wear.

Scott Kozutsky

12-05-2016, 08:55

http://www.amazon.com/Park-Tool-Screw-Type-Chain/dp/B01EONOJ78 for 35 or 25 chain. It's the best chain tool I've yet used for any chain.

Chain sprockets for bike chain. Bike chain has better availible tools, is availible locally everywhere, is lighter per foot than 35 (expensive stuff is the same as 25), and larger teeth mean better fault tolerance when tensioning.

MechEng83

12-05-2016, 08:58

An inside corner bracket for the 1" REV extrusion similar to the 15mm version: http://www.revrobotics.com/product/rev-41-1038/

A breakout board for the Talon SRX that contains the index signal pin.

A breakout board for the Talon SRX that plugs right into the motor controller, rather than requiring those really thin cables.

roboruler

12-05-2016, 08:59

This and the right-angle adapter would be incredibly useful.

What about steel though? Especially with the smaller gears, the weight increase isn't going to be that significant, and if case hardened, I can't imagine you'd see much wear.

Gears breaking isn't normally a huge problem but it would be great to have some drop in 4140 steel replacements for gears maybe up to 24 tooth sizes.

Hopefully they could also be black oxide coated for superior performance :)

Yes, the weight increase in terms of total gearbox wouldn't be very significant so this would be a viable option.

OccamzRazor

12-05-2016, 09:04

I second what Sperkowsky said about the metal versaplanetary adapter and gussets. If it was metal it could be a lot smaller.

I would also like to see the versaplanetary encoder housing be made out of the same metal as the gearboxes because we had two of the plastic ones create a failure where once the encoder cracked and failed the entire gearbox would fall to pieces in our robot. The bolts failed in double shear and we had three pieces of each bolt every time this happened on two different gearboxes. I will attach photos to show the failure. I think we already sent this to Vex but I will check on that. I think vibration was the cause of the failure and not overloading based on our applications.

I also strongly agree with what Marshall said and will add a little on to that. If the AndyMark kit came with bumper instructions and sheet metal hardware for next year I feel like some of the teams with fewer resources in NC would actually arrive to competition with bumpers and I would not have to help them build the bumpers before inspection! It would be nice to have something sort of like an "add plywood, noodle, and cloth kit" and you have a robot ready for inspection.

roboruler

12-05-2016, 09:05

A breakout board for the Talon SRX that contains the index signal pin.

A breakout board for the Talon SRX that plugs right into the motor controller, rather than requiring those really thin cables.

Not hardware, but the ability to set brake/coast in a Talon SRX with code.

Multiple sizes of Talon SRX data cable, currently the only size is 12" which can be difficult to work with.

Andrew Schreiber

12-05-2016, 09:07

Not hardware, but the ability to set brake/coast in a Talon SRX with code.

Uh, using CAN you can.

ASD20

12-05-2016, 09:21

Multiple sizes of Talon SRX data cable, currently the only size is 12" which can be difficult to work with.

+1

MechEng83

12-05-2016, 09:28

Multiple sizes of Talon SRX data cable, currently the only size is 12" which can be difficult to work with.

http://www.andymark.com/product-p/am-2617.htm AndyMark sells a 6" version. I was also able to find 20cm version from random internet sources (search for 0.05" or 1.27mm 10 pin), but I agree, having multiple length options would be nice.

hrench

12-05-2016, 09:42

a CAN plug-in vision aiming module.

messer5740

12-05-2016, 09:43

Kellen Hill

12-05-2016, 09:50

-4"x1.5" and 4"x2" Aluminum Wheels with 1/2" Hex Broach
-Anti-backdrive stage for VersaPlanetary
-Disc Brake set up with 1/2" Hex or "Standard" Sprocket Hole Pattern

For the anti-backdrive stage, you could even add in a switch to the stage, similar to a ratchet wrench, to engage, disengage, or flip the direction of the anti-backdrive.

Billfred

12-05-2016, 09:53

That is very difficult for suppliers, it is almost a gamble, as they have to buy or fabricate parts in advance, and if they are not useful for a particular season then that is a huge burden on them. A way around it is to get certain suppliers like Andymark and Vex in the loop in terms of the season so they can plan ahead, but it is really not ideal at all.

What about the AndyMark tank treads? That must have been the best gamble they ever had for they only came out about a month prior to kickoff. I do feel that suppliers should be in the loop so they can prepare their inventory for the influx of purchasing specific parts.

Three key distributors--AndyMark, VEX, and REV--were given a few high-level details (http://www.firstinspires.org/robotics/frc/blog/distributors) about the game in September and October.

They were given general information such as that the robots would be driving over obstacles, climbing, and throwing game objects. All distributors made their own decisions about stocking levels and what components they should stock. As an example, while we told distributors that robots would be climbing obstacles, we did not tell them what specific components we thought would be useful in addressing that challenge. Each made their own business decisions. In some individual cases distributors were given more detailed information out of necessity. For example, as AndyMark had agreed to make the game objects available to teams, they knew about, and stocked, boulders ahead of time. Specific details like this were on a 'need to know' basis, if they didn't need to know, they didn't get to know.

ASD20

12-05-2016, 09:54

What about the AndyMark tank treads? That must have been the best gamble they ever had for they only came out about a month prior to kickoff. I do feel that suppliers should be in the loop so they can prepare their inventory for the influx of purchasing specific parts.

This year AndyMark and a few other suppliers were told some details about the game and that is why they came out with Rhino Treads.

Andrew Schreiber

12-05-2016, 10:03

This year AndyMark and a few other suppliers were told some details about the game and that is why they came out with Rhino Treads.

[citation needed]

Bkeeneykid

12-05-2016, 10:08

[citation needed]

Citation: http://www.firstinspires.org/robotics/frc/blog/distributors

It doesn't say that the Rhino drive was a direct result of finding out about the game, but it seems a perfect product for the game, so I'd imaging it is something similar.

Nemo

12-05-2016, 10:09

Rollers are a pain. It would be nice if there were a couple more COTS methods to transmit torque to a roller. The only one I know of is from Competition Robot Parts.

Nemo

12-05-2016, 10:12

A COTS 4 stage gearbox for a single CIM would be pretty handy for arms.

mklinker

12-05-2016, 10:15

I would like to see a ratcheting gear and pawl. It would be nice if the ratcheting gear had a 1/2 inch hex broached bore.

Option B would be a ratcheting gear with the standard FIRST bolt circle to attach to a hub.

maxnz

12-05-2016, 10:18

A potentiometer that is designed to work with VEX ThunderHex shafts.

Ryan_Todd

12-05-2016, 10:25

...spacer inserts for tubes. These let you do through-bolt connections that can be tightened without crushing the tube, so you actually have a strong bolted joint. For VexPro in particular, spacers like this that fit their Versaframe extrusion sizes could be very useful for some teams.

+1 million on this one.

In recent years, we usually end up 3D printing all of our anti-crush supports, or else making do with lots of little cut-to-length tube spacers. With the first option, we waste time redesigning and printing the custom support blocks every year; with the second option, we waste time fumbling with (and dropping, losing, and needing to cut replacements for) dozens of tiny round spacers during assembly and maintenance operations.

Standard anti-crush supports that fit inside the VersaFrame extrusions, on the other hand, should be fairly cost-effective if injection-molded en masse!

Knufire

12-05-2016, 10:25

A potentiometer that is designed to work with VEX ThunderHex shafts.

You can do this pretty easy already. Just drill the center of the shaft out to 1/4", hacksaw a slit ~0.75" down the length of the shaft, and put a shaft collar over the slit. The shaft collar will now clamp the potentiometer shaft like a collet would.

maxnz

12-05-2016, 10:31

You can do this pretty easy already. Just drill the center of the shaft out to 1/4", hacksaw a slit ~0.75" down the length of the shaft, and put a shaft collar over the slit. The shaft collar will now clamp the potentiometer shaft like a collet would.

Yeah, but if it had the pwm cable pre-attached, like most VEX EDR electronics do, then it would be a lot easier to wire. That's mainly what I was getting at.

Greg Needel

12-05-2016, 10:39

An inside corner bracket for the 1" REV extrusion similar to the 15mm version: http://www.revrobotics.com/product/rev-41-1038/

http://i.giphy.com/B5QDyiw4j8Xrq.gif

Chris is me

12-05-2016, 10:39

-Anti-backdrive stage for VersaPlanetary
-Disc Brake set up with 1/2" Hex or "Standard" Sprocket Hole Pattern

Was just thinking about both of these.

An anti-backdrive VP stage would be awesome - that is basically the only feature I miss from the old DeWalt transmissions, and it can't be *that* hard to do, right?

I would really like 4140 pinion gears (at least 18T, 20T, 24T) for high load applications. Aluminum works sometimes, but sometimes you want steel.

CalTran

12-05-2016, 10:40

This year AndyMark and a few other suppliers were told some details about the game and that is why they came out with Rhino Treads.

Citation: http://www.firstinspires.org/robotics/frc/blog/distributors

It doesn't say that the Rhino drive was a direct result of finding out about the game, but it seems a perfect product for the game, so I'd imaging it is something similar.

I would imagine they had already been designing the Rhino tread for some time previously, and being alerted that the new game would have "driving over obstacles" simply sped up the time frame for releasing it. A COTS tread system had always been something people wanted (for whatever reason :P).

ajlapp

12-05-2016, 11:03

For those interested, this chain tool is still available in the wild.

http://www.davesmotors.com/DarkSoul-25-Chain-Breaker-Tool-3466.html

We used to sell it...it's a long story as to why we do not anymore.

This is hands down the best chain tool for #25 chain that exists....the main advantage is the inclusion of a re-press mandrel that allows you to eliminate master links.

Michael Hill

12-05-2016, 11:23

BrendanB

12-05-2016, 11:27

Will that work on the Vex #25 chain? It seems a bit thicker than other #25 chain.

Yes it works with Vex #25 chain.

It is the best chain tool I've used.

Chris is me

12-05-2016, 11:27

Will that work on the Vex #25 chain? It seems a bit thicker than other #25 chain.

Yes. We used it this year on Vex chain - if anything the extra thickness makes it harder to drive the pin too far out, so it works better with Vex chain.

JesseK

12-05-2016, 11:35

Monochron

12-05-2016, 11:54

Aluminum HTD pulleys with more hearty outer walls. Almost all of our larger diameter pulleys had the wall ring pop off at some point during the season. The belts themselves very rarely slipped off as they were fairly well aligned, but I would love to have not had to deal with it over and over.

If they can't get away from the ring design of the walls, maybe make the walls a little larger so that you could tap and screw it back on after it pops off? It's doable right now with (I think) a #4 screw, but something larger would be nice to work with.

JesseK

12-05-2016, 12:04

If they can't get away from the ring design of the walls, maybe make the walls a little larger so that you could tap and screw it back on after it pops off? It's doable right now with (I think) a #4 screw, but something larger would be nice to work with.

You could tap the base aluminum pulley, close to the ring, and use a washer to retain the ring. This is similar to how many gearboxes retain bearings (AM Toughbox Nano, WCP DS gearboxes, and a few others I'm sure).

ThaddeusMaximus

12-05-2016, 12:08

VersaPlanetary "Inverter"- allow you to run a motor on the side of the planetary. Our team fobbed our own with a dual motor input and some shenanigans, but COTS would be nicer. The issue with planetaries' packaging is that they package long.

Monochron

12-05-2016, 12:13

Rollers are a pain. It would be nice if there were a couple more COTS methods to transmit torque to a roller. The only one I know of is from Competition Robot Parts.

Use a VersaHub. You can attach the VersaHub to larger diameter pulleys by buying or printing some sort of insert with an ID the same as the hub and an OD that matches the ID of your roller. We did that this year with our 4" diameter roller and it worked great.

Monochron

12-05-2016, 12:14

You could tap the base aluminum pulley, close to the ring, and use a washer to retain the ring. This is similar to how many gearboxes retain bearings (AM Toughbox Nano, WCP DS gearboxes, and a few others I'm sure).

Thanks, that's a great idea.

bigbeezy

12-05-2016, 12:55

Mr V

12-05-2016, 13:01

Parts to make the construction of bumpers easier. I know Andy had a design for a corner piece and I still want to see it made. It would make the lives of those who help other teams with making bumpers every year much easier.

AndyMark sells this bumper kit for the AM14U3 http://www.andymark.com/AM14U3-p/am-3152.htm Much of that was included in the version shipped as the KOP chassis, it included the right and left angle brackets, the thumb screws and the t nuts. There was also a separate instruction sheet on how to use those parts to create bumpers. It did not include the corner angles but personally I prefer to glue and screw the two pieces together and have found that method to be more than robust enough.

Bkeeneykid

12-05-2016, 13:14

I would like to see a better solution for using LED's. Right now LED's paralyze my team with how many choices / setups there are, so usually there's a mediocre attempt at them but never a finished product.
- How do we connect power to the LED's?
- Which LED brand, model, and length do we use?
- Do we really have to care that each light is addressable, seriously?
- To control them do we use an offboard processor, use a Spike, or is there a better way?

Would love to have something simpler that doesn't depend on in-house custom circuitry or an arduino. Plug this 12" LED strip into this device, then plug this device into the PDB and into the RoboRIO using these connectors. Then use this sample code to get going with writing different colors/brightnesses or blinking lights to the LED's.

FWIW, introductory courses in embedded electronics in college were all about blinking LED's, and connection of those circuits to the corresponding code was way more straightforward than the FRC LED situation.

Thing is, most LED strips are one of two solutions: RGB LEDs, or Addressable WS8211 or similar LEDs. I know teams that I know (I've never used LED Strips on a robot before) use the VRM's 2 Amp 5 Volt rail to power LEDs. I'd recommend one of two models: Adafruit Dotstar (https://www.adafruit.com/products/2239) or Adafruit NeoPixels (https://www.adafruit.com/products/1376). These are both addressable. In reality, you don't need addressable really, but it makes controlling them easier, and sometimes it's just nicer to have control of individual sections. The main difference between the two, is that one (the Dotstar) is able to be controlled directly from the RoboRIO, albeit at a higher price. The NeoPixels are much more common, but require a special timing protocol, which must be driven by an Arduino or some other single process device. You may be able to find places that have basically identical strips to these Adafruit brands, just search for WS8211,WS8212,WS8212B, or WK6812 LED strips on Ebay or other shopping website. DotStar strips use a less common APA102 driver on the chips, so you'll find less of these types of strips on places like Ebay.

JesseK

12-05-2016, 13:31

Thing is, most LED strips are one of two solutions: RGB LEDs, or Addressable WS8211 or similar LEDs. I know teams that I know (I've never used LED Strips on a robot before) use the VRM's 2 Amp 5 Volt rail to power LEDs. I'd recommend one of two models: Adafruit Dotstar (https://www.adafruit.com/products/2239) or Adafruit NeoPixels (https://www.adafruit.com/products/1376). These are both addressable. In reality, you don't need addressable really, but it makes controlling them easier, and sometimes it's just nicer to have control of individual sections. The main difference between the two, is that one (the Dotstar) is able to be controlled directly from the RoboRIO, albeit at a higher price. The NeoPixels are much more common, but require a special timing protocol, which must be driven by an Arduino or some other single process device. You may be able to find places that have basically identical strips to these Adafruit brands, just search for WS8211,WS8212,WS8212B, or WK6812 LED strips on Ebay or other shopping website. DotStar strips use a less common APA102 driver on the chips, so you'll find less of these types of strips on places like Ebay.

I get it - there are options. Yet they're wide, varied, sometimes incompatible and sometimes take the power ports we'd rather put to other uses.

Or perhaps CTRE could come out with a couple more 5V ports on the VRM?

Knufire

12-05-2016, 13:34

Yeah, but if it had the pwm cable pre-attached, like most VEX EDR electronics do, then it would be a lot easier to wire. That's mainly what I was getting at.

Try this: http://www.andymark.com/product-p/am-2899.htm.

It's more expensive than your standard pot, but much less nosiy, much smaller, and comes with a pre-terminated cable.

2. Banebot sized rollers out of a hardier plastic (polyurethane?).

AM Stealth Wheels?

4. Something to help with chain tensioning, perhaps a small kit? (I have no idea how this would work though).

If this is a chain that never spins a full revolution (arms, elevators), MISUMI sells some made-for-chain turnbuckles that connect with masterlinks.

5. A motor testing kit to check for damaged motors.

http://www.andymark.com/product-p/am-2671.htm

On the topic of rollers, I've found the secret is the 1.25 x 0.0625 tube. The ~1.125 ID makes a number of COTS hubs and bearings fit nicely.

CalTran

12-05-2016, 13:40

Try this: http://www.andymark.com/product-p/am-2899.

It's more expensive than your standard pot, but much less nosiy, much smaller, and comes with a pre-terminated cable.

Try this link. (http://www.andymark.com/product-p/am-2899.htm) For whatever reason, (Not a web developer so can't tell you why, AM's links require the .htm at the end.

mastachyra

12-05-2016, 13:51

I was drawing up plans for a linear actuator that uses either the BAG motor or 775pro. It could be built just like the DART actuators and be much smaller. I just don't have access to any machines that can help make it.

It'd be a great off-season project for a team and I think they'd sell like hot(cheese)cakes

maxnz

12-05-2016, 14:17

Try this: http://www.andymark.com/product-p/am-2899.htm.

It's more expensive than your standard pot, but much less nosiy, much smaller, and comes with a pre-terminated cable.

But if VEX makes it, then it could be designed to work with the ThunderHex shaft without having to drill it out.

Also, it seems that you still would need to crimp or sauter the other end of that connection wire. I'm hoping to just have a potentiometer that has a cable with a pwm end with the other end connected internally. It's a LOT easier to wire.

Sperkowsky

12-05-2016, 14:20

But if VEX makes it, then it could be designed to work with the ThunderHex shaft without having to drill it out.

Also, it seems that you still would need to crimp or sauter the other end of that connection wire. I'm hoping to just have a potentiometer that has a cable with a pwm end with the other end connected internally. It's a LOT easier to wire.
This is Definitly a valid product. The cable thing doesn't bother me much but it would be really nice to have a potentiometer that wrapped around a hex shaft.

marshall

12-05-2016, 14:35

AndyMark sells this bumper kit for the AM14U3 http://www.andymark.com/AM14U3-p/am-3152.htm Much of that was included in the version shipped as the KOP chassis, it included the right and left angle brackets, the thumb screws and the t nuts. There was also a separate instruction sheet on how to use those parts to create bumpers. It did not include the corner angles but personally I prefer to glue and screw the two pieces together and have found that method to be more than robust enough.

Not what I want. It's not simple enough (And yes, I know how simple it is). Andy knows what I want. He had a 3D printed version of it at champs 2 years ago. Someone at AM should tell him to make it already.

a CAN plug-in vision aiming module.

Ain't gonna happen anytime soon for a lot of reasons. Unless of course all you want is the PIXY CAM with a CAN interface... you can make that happen without a whole lot of effort... use the HERO board to do it maybe?

All that being said, 900 is actively talking about how to "cheesecake" vision onto other robots in the future... no idea what that means at the moment but we're talking about it.

The biggest issue with vision isn't the vision or the detection. It's getting more teams to add encoders to their drivetrains and mechanisms. You need feedback to make use of the vision data.

I'd love to see more COTS options for encoder integration.

I would also love to see the CIM-Encoder that AM introduced this season improved. It's hollow and the little center spacer plate isn't square. Make it filled in, more robust, and square the center plate.

And I REALLY hope brushless is coming based on what CTRE was showing off. I'd love to see it happen.

jeremylee

12-05-2016, 14:42

FrankJ

12-05-2016, 15:05

A lot of the industrial sensors do not pull low enough to reliably switch the Roborio 3.3 Volt digital input. A packaged opto-isolator that sinks the input to the roborio level would be nice. Maybe even with a transistor that inverts the logic back.

A Spike replacement

dv/dt

12-05-2016, 15:09

Andrew Schreiber

12-05-2016, 15:10

Greg Needel

12-05-2016, 15:10

I would like to see a better solution for using LED's. Right now LED's paralyze my team with how many choices / setups there are, so usually there's a mediocre attempt at them but never a finished product.
- How do we connect power to the LED's?
- Which LED brand, model, and length do we use?
- Do we really have to care that each light is addressable, seriously?
- To control them do we use an offboard processor, use a Spike, or is there a better way?

Would love to have something simpler that doesn't depend on in-house custom circuitry or an arduino. Plug this 12" LED strip into this device, then plug this device into the PDB and into the RoboRIO using these connectors. Then use this sample code to get going with writing different colors/brightnesses or blinking lights to the LED's.

So we built a prototype of a product about a year ago to do simple LED control called the "blinkin Board"

The basic idea was to allow on a single board the ability to drive the WS281* LEDs or 12v RGB LEDs. The voltage buck 12 to 5 with 3 amps of supply is on board, so just give it 12 volts and it would work.

The real beauty (in our minds) was the fact that you can control either kind of strip with a PWM input, we were able to sub-divide the standard PWM signal into tons of discrete signals and using a provided chart teams could make their LEDs do things with no hard programming required. There are a bunch of jumpers on the board so you can select things like your team colors & strip length.

We got the prototype almost ready for production (needed a bit more DFM work and software) but we ran out of time as we needed to focus on other things (like the SPARK). We also were not sure how many teams would be interested in something like this to justify the effort to bring it to market. It is still something we can definitely make, we just need to figure out where on the priority list it falls compared to some of the other large initiatives REV is working on.

http://i.imgur.com/z40IgAkl.png

Chris is me

12-05-2016, 15:12

Smaller 3/8" hex bearings. Ideally ones that could be used in a 1x1 tube. So like 7/8" OD with a flange. We used crummy conveyor bearings from Grainger with our collector, which surprisingly didn't fail during competition.

This product used to exist from AM, but it required such a thin inner race at the points that the bearings would fail catastrophically at relatively low loads.

thefro526

12-05-2016, 15:44

This product used to exist from AM, but it required such a thin inner race at the points that the bearings would fail catastrophically at relatively low loads.

FWIW, I would love to see FR6's with a 3/8 Hex bore make a come back, I've used them in 2013, 2014 and 2016 without issue. (Bought stock when they were discontinued) From what I've seen, they can be used in Auxilary mechanism, specifically high reduction gear boxes and intake type gearboxes without issue.

ASD20

12-05-2016, 15:49

TehSwegGey

12-05-2016, 16:33

Every broken gear picture on CD has the teeth sheered off. I've never seen the body of a gear crack.

How possible would a combination gear be? Something with a lighter but still strong internal portion and a steel outer? It might be better than holes for the smaller gears? Like this maybe?

http://s32.postimg.org/98yslkhs1/gear_idea.jpg (http://postimg.org/image/98yslkhs1/)

I'm new to this stuff...

Rangel(kf7fdb)

12-05-2016, 16:48

Ain't gonna happen anytime soon for a lot of reasons. Unless of course all you want is the PIXY CAM with a CAN interface... you can make that happen without a whole lot of effort... use the HERO board to do it maybe?

All that being said, 900 is actively talking about how to "cheesecake" vision onto other robots in the future... no idea what that means at the moment but we're talking about it.

The biggest issue with vision isn't the vision or the detection. It's getting more teams to add encoders to their drivetrains and mechanisms. You need feedback to make use of the vision data.

I'd love to see more COTS options for encoder integration.

I would also love to see the CIM-Encoder that AM introduced this season improved. It's hollow and the little center spacer plate isn't square. Make it filled in, more robust, and square the center plate.

And I REALLY hope brushless is coming based on what CTRE was showing off. I'd love to see it happen.

Why couldn't a gyro be an alternative to having encoders on the robot? If the gyro was part of the board, it could likely still be kept all together. I'm not sure if we even used the encoders for our vision tracking this year and we hit every autonomous shot at champs. I'd imagine a game with a bigger goal would be even better.

Edit: Granted, we did use the encoders for going forward a set distance in teleop. This probably would effect our accuracy in autonomous. I would imagine not by too much though. In teleop though, auto tracking would be unaffected by not having encoders.

Andrew Schreiber

12-05-2016, 16:53

Why couldn't a gyro be an alternative to having encoders on the robot? If the gyro was part of the board, it could likely still be kept all together. I'm not sure if we even used the encoders for our vision tracking this year and we hit every autonomous shot at champs. I'd imagine a game with a bigger goal would be even better.

Edit: Granted, we did use the encoders for going forward a set distance in teleop. This probably would effect our accuracy in autonomous. I would imagine not by too much though. In teleop though, auto tracking would be unaffected by not having encoders.

Gyros tend to need to be level. You can cheat to an extent with some of the IMU boards doing a self leveling routine on startup and I guess that's probably a viable approach. Just don't forget it.

But why Encoders - At some point you need to get to a point on the field and that's pretty hard without encoders in the drive.

GDG 2337

12-05-2016, 17:24

FR6-ZZ HEX PS2 Radial Bearings at Boca Bearing, showing 4700 in stock

http://www.bocabearings.com/bearing-inventory/Radial-Bearings/18125/0-3750x0-8750x0-2812-FR6ZZHEXPS2

asid61

12-05-2016, 18:57

FR6-ZZ HEX PS2 Radial Bearings at Boca Bearing, showing 4700 in stock

http://www.bocabearings.com/bearing-inventory/Radial-Bearings/18125/0-3750x0-8750x0-2812-FR6ZZHEXPS2

And look at that- only $14 each! What a steal. /sarcasm
Seriously though, nice find. Good to know there's a source out there for 3/8" hex bearings in tough situations. However, I would still want a 7/8" OD 3/8" hex bearing available from Vex or AM.

asid61

12-05-2016, 18:58

Munchskull

12-05-2016, 20:50

Motor question, are the RS 775 and RS 550 standard motor sizes? If so how are they measured?

PAR_WIG1350

12-05-2016, 21:24

Motor question, are the RS 775 and RS 550 standard motor sizes? If so how are they measured?

Here is what you are looking for (http://www.mabuchi-motor.co.jp/en_US/technic/t_0302.html)

Peter Johnson

12-05-2016, 22:06

I would like to see a better solution for using LED's. Right now LED's paralyze my team with how many choices / setups there are, so usually there's a mediocre attempt at them but never a finished product.
- How do we connect power to the LED's?
- Which LED brand, model, and length do we use?
- Do we really have to care that each light is addressable, seriously?
- To control them do we use an offboard processor, use a Spike, or is there a better way?

Would love to have something simpler that doesn't depend on in-house custom circuitry or an arduino. Plug this 12" LED strip into this device, then plug this device into the PDB and into the RoboRIO using these connectors. Then use this sample code to get going with writing different colors/brightnesses or blinking lights to the LED's.

FWIW, introductory courses in embedded electronics in college were all about blinking LED's, and connection of those circuits to the corresponding code was way more straightforward than the FRC LED situation.

We've used standard cut-to-length non-addressable 12V LED strips (Amazon sells lots of these in various colors) and this tiny board from pololu to control them: https://www.pololu.com/product/2802

Basically the polulu board is a simple digital switch (think of it like a spike without the ability to reverse the voltage polarity), controlled by a PWM signal. The linked one above is 3A but they also have higher current ones. The wiring diagram shows how to wire it up. Load is LED strip, source is either 5V or 12V (depending on LED strip voltage) from VRM. The PWM comes from a PWM output on the roborio. You do need 5V in from somewhere too; if you're using 5V LEDs or a PWM from a MXP board you can get 5V from that connection, or you can get it from the VRM or RoboRIO DIO. I think we used the Talon class in software to control the PWM output--set(0) turned the LEDs off, set(1) turned them on. Easy enough to do das blinkenlights from there with software timing.

nuclearnerd

12-05-2016, 22:27

So we built a prototype of a product about a year ago to do simple LED control called the "blinkin Board"

We got the prototype almost ready for production (needed a bit more DFM work and software) but we ran out of time as we needed to focus on other things (like the SPARK). We also were not sure how many teams would be interested in something like this to justify the effort to bring it to market. It is still something we can definitely make, we just need to figure out where on the priority list it falls compared to some of the other large initiatives REV is working on.

Oh I would definitely buy this. The need for a dedicated power supply and controller has kept me from prioritizing blinkinlights in the past. Your board looks like a pretty simple drop-in solution.

nuclearnerd

12-05-2016, 22:29

A potentiometer that is designed to work with VEX ThunderHex shafts.

How about an absolute encoder that is designed to work on hex shafts? http://www.chiefdelphi.com/forums/showthread.php?p=1569705

ratdude747

12-05-2016, 23:06

A Spike replacement

I remember a few years ago FIRST beta tested some dual relay modules... Obviously it didn't see the light of day, which is a shame.

Sure, it's just a relay... but a lot of things don't require variable control and in the real world relays are used all over the place (automotive, etc.). Now, they've become so forgotten that everybody (to quote a professor I know) "uses a helicopter to cross the street" by using Victors and the like for things that really don't need one.

I did note that spikes are listed as discontinued on VEX's site but that may not be news (not affiliated with a team, so I don't keep up with that much).

Perhaps even solid state relay options? While not exactly a huge benifit it's modern technology and if anything part of the control system goal is exposure to modern technology (adoption of CAN bus comes to mind).

mrnoble

12-05-2016, 23:10

Oh I would definitely buy this. The need for a dedicated power supply and controller has kept me from prioritizing blinkinlights in the past. Your board looks like a pretty simple drop-in solution.

I'd be all over this too. I sure hope your market research shows demand, I'd love to see it get built.

mrnoble

12-05-2016, 23:18

I think it was a little late last year when I voiced a hope for inverse mounted CIM gearboxes (like http://www.chiefdelphi.com/forums/showthread.php?t=140713) as a COTS item; maybe this year the Wizards at WCP will bring one to market. I'd also love to see the Raw Box made more like Joey Milia's original version; my team would probably keep several sets of that box in stock, it seems like one of the better designs I've ever seen.

hrench

13-05-2016, 09:11

I want a CAN plug-in vision aiming module

Ain't gonna happen anytime soon for a lot of reasons. Unless of course all you want is the PIXY CAM with a CAN interface... you can make that happen without a whole lot of effort... use the HERO board to do it maybe?

All that being said, 900 is actively talking about how to "cheesecake" vision onto other robots in the future... no idea what that means at the moment but we're talking about it.

Yes, I guess I'm talking about 'cheesecake'. Making code and 'teaching' it in the time we have after a running robot has always been the impediment.

I want a module that has the programming built in to actually run the wheels and drive forward/back for the best distance. Or for a turret, to aim azimuth and elevation.

And it would ideally have a 'learning' mode where you'd manually make shots and it would recognize where the aim was to duplicate it.

The biggest issue with vision isn't the vision or the detection. It's getting more teams to add encoders to their drivetrains and mechanisms. You need feedback to make use of the vision data.

Our robot has had a camera and encoders on it every year, necessary for any autonomous.

I'd love to see more COTS options for encoder integration.

I would also love to see the CIM-Encoder that AM introduced this season improved. It's hollow and the little center spacer plate isn't square. Make it filled in, more robust, and square the center plate.

And I REALLY hope brushless is coming based on what CTRE was showing off. I'd love to see it happen.

Yes this would be great. Also a 'cheesecake' aiming system could have a camera/multiple cameras pointed at the carpet and read speed and distance from that. Maybe I'm getting a little too complicated.

On the flip side, if every team has automated aiming and shooting, it may make amazing robots but less fun of a game.

Eric Scheuing

13-05-2016, 09:19

How possible would a combination gear be? Something with a lighter but still strong internal portion and a steel outer? It might be better than holes for the smaller gears? Like this maybe?

http://s32.postimg.org/98yslkhs1/gear_idea.jpg (http://postimg.org/image/98yslkhs1/)

I'm new to this stuff...

I think a gear similar to this would be great. I'd make a simple change though to make it easier to manufacture and therefore (hopefully) cheaper. The gear would be entirely steel, and just case-harden the area you have labeled as steel. Keep a small bore through the center for people who want to use small diameter shafts, but by only case hardening around the outside, it leaves the center area machinable. That way you could use whatever profile you wanted in the center without having to worry about sacrificing structural integrity of the gear. Ofc I'd like to see an option for 1/2" hex bore as well for the teams that don't have a broach or a press large enough to accomodate.

JesseK

13-05-2016, 13:36

We've used standard cut-to-length non-addressable 12V LED strips (Amazon sells lots of these in various colors) and this tiny board from pololu to control them: https://www.pololu.com/product/2802

Basically the polulu board is a simple digital switch (think of it like a spike without the ability to reverse the voltage polarity), controlled by a PWM signal. The linked one above is 3A but they also have higher current ones. The wiring diagram shows how to wire it up. Load is LED strip, source is either 5V or 12V (depending on LED strip voltage) from VRM. The PWM comes from a PWM output on the roborio. You do need 5V in from somewhere too; if you're using 5V LEDs or a PWM from a MXP board you can get 5V from that connection, or you can get it from the VRM or RoboRIO DIO. I think we used the Talon class in software to control the PWM output--set(0) turned the LEDs off, set(1) turned them on. Easy enough to do das blinkenlights from there with software timing.

Thanks for sharing! We just picked up a few of these to experiment with since our 2016 bot would have had at least a few uses for any kind of LED driver feedback, but we couldn't find any spikes in-house at the time.

So we built a prototype of a product about a year ago to do simple LED control called the "blinkin Board" ...

Cool! I will keep an eye out just in case something comes out.

jwfoss

13-05-2016, 13:46

So we built a prototype of a product about a year ago to do simple LED control called the "blinkin Board"

A system like this definitely makes LEDs less cumbersome. 558 would be very interested in this set up.

Chak

13-05-2016, 14:10

A bigger version of the versaplanetary.

nuclearnerd

13-05-2016, 14:50

Some of these are (unmet) repeats from my 2015 wishlist:

seconding a larger versa planetary. A stronger output stage (with more than two extremely thin #10 mounting holes), longer output shaft (on two bearings maybe, steel ring gears, aluminum encoder stages, and would actually installing the anti-torque pins at the factory would help. We went through hundreds of dollars of busted stages this year :( For larger arms, teams shouldn't have to build their own chain stage - a strong final stage could work as a direct drive!
A system of hubs and bearings for 1" OD tube axles. 1/2" 7075 hex is not up to the challenge of transmitting large torque, over long distances with little twist. 1" tube would fit in AndyMark and Vex bolt circles, and be a lot stiffer
Repeated from up-thread: A pneumatic brake and/or ratchet stage for a versa planetary. This could be small and lightweight to go on the motor side for mechanism holding, or beefy to go on the output side for something like a catapult release
A clutch stage for a planetary output (or maybe just something that slips on a hex shaft. This would let teams use air-cooled motors like the 775 pro without worrying about stalling and burning them out
Something like Vex's 217-4183 bearing mount, but longer, with set distances between holes to fit standard belt-pulley / chain-sprocket spacings. Teams that don't have machining resources have a heck of a time mounting pulleys at the proper center spacing
Longer ribbon cable for talon SRX's, and/or cheaper breakouts

I'll probably come up with more...

JesseK

13-05-2016, 15:22

A clutch stage for a planetary output (or maybe just something that slips on a hex shaft. This would let teams use air-cooled motors like the 775 pro without worrying about stalling and burning them out

Hmm, I generally really like this one...

Munchskull

13-05-2016, 15:36

I have mentioned this before but I would love a VP output stage with a female 1/2" hex coupler.

Also more small usable motors would be great. Stuff in the RS-550 size.

Said this earlier but an electric solenoid and coupler for shifting with no pneumatics would be epic.

Ari423

13-05-2016, 15:39

I have mentioned this before but I would love a VP output stage with a female 1/2" hex coupler.

Why not just use the male 1/2" hex output shaft and one of these 217-4008 (http://www.vexrobotics.com/217-4008.html)?

Sperkowsky

13-05-2016, 15:43

Why not just use the male 1/2" hex output shaft and one of these 217-4008 (http://www.vexrobotics.com/217-4008.html)?

Its a matter of form factor.

Munchskull

13-05-2016, 15:59

Why not just use the male 1/2" hex output shaft and one of these 217-4008 (http://www.vexrobotics.com/217-4008.html)?

Because it would be nicer just to take a piece of hex shafts of any length and have that be your output.

AdamHeard

13-05-2016, 16:07

Because it would be nicer just to take a piece of hex shafts of any length and have that be your output.

If you look at how the hex shaft is held in a versaplanet output, it wouldn't be crazy hard to do your own.

Vex and only sell so many variants of their products w/o losing money due to the increased difficulty of inventory forecasting.

Chris is me

13-05-2016, 16:45

If you look at how the hex shaft is held in a versaplanet output, it wouldn't be crazy hard to do your own.

Wouldn't you have to hob your own spline to do that? I would think that's beyond the capabilities of most teams.

Now making your own female hex coupler, not very hard.

Mark Sheridan

13-05-2016, 16:54

Wouldn't you have to hob your own spline to do that? I would think that's beyond the capabilities of most teams.

Now making your own female hex coupler, not very hard.

The spline is a separate piece. The shaft and spline are combined with a dutch key. I almost did this last season: Press out the shaft and insert a new one and drill in a new hole for the dutch key.

Munchskull

13-05-2016, 22:15

Wouldn't you have to hob your own spline to do that? I would think that's beyond the capabilities of most teams.

Now making your own female hex coupler, not very hard.

You would have to do the spline. I am wondering if it is a standard size, if so there might be external rotory broachs for it.

thatprogrammer

13-05-2016, 22:23

A ball shifter with a longer output!
Hex gt2 pulleys

roboruler

13-05-2016, 22:33

You would have to do the spline. I am wondering if it is a standard size, if so there might be external rotory broachs for it.

I only found this out after being show by a team at CMP this year, but the output shaft assembly ( minus bearing block) is actually in two pieces the spline and the output shaft. As I see it, it would be possible to turn down the end of a length of hex shaft to fit into the spline and re-join them.

In regards to your ½ hex socket. Couldn’t you just cut down the length of the ½ hex output shaft to say ½ inch in length then make a single piece coupler say a 20mm aluminium round aluminium rod with a ½ inch hole in it and then hex broached. Then just attach it to the cut down output shaft with a set-screw

happyWobot

13-05-2016, 22:46

I'm sure I'm missing something and some of this has been alluded to, but how about a small, lightweight, easily mounted replacement for a window motor? Something with low rpm and modest torque. The window motors are flimsy and hard to mount. I love the versaplanetaries but would prefer not to have to use a 3 stage reduction to get to the sub-100 rpm realm.
Clue me in on what you use in these applications.

I was wondering how long it was going to take before someone got around to this. It's unreasonable and somewhat silly to try and turn a VP into a low RPM high torque wervo. They aren't reqlly designed for that.

While a good high torque servo for FRC applications would be very welcome, especially one with its own encoder, what I would rather have is a new transmission designed specifically for window motors (all of them), windshield wiper motors, door motors, rear window motors, etc.

A transmission of this type should be capable of interfacing with gear, square, or module 2. It should be capable of direct drive config, round or Hex Output Shaft and have the ability to mount an encoder (potentiometer) to it.

There is an advantage to these kinds of motors if they are legal. There are lots of different types, some are very inexpensive, some are self braking, and you can get them at just about any corner auto parts store. The problem is there is no standard means of connection them. If it was as simplement as 3 screws to mount or replace more people would use them. And some of the currently legal ones are crazy powerful. But it can take an entire build season to figure out a way to mount and connect one.

I'm not sure why they are considered flimsy though. Maybe they weren't mounted correctly?

wmarshall11

13-05-2016, 23:05

happyWobot

13-05-2016, 23:13

If you look at how the hex shaft is held in a versaplanet output...

Yes I have. Generally I've been very pleased with the VP. Through 4 events they held together running a shooter that worked outside the robot perimeter. They took unbelievable punishment. But they have one potential flaw. We saw the shaft fly out of the VP twice this whole season. Mind you right before the second time the case was making a rattle we couldn't identify. It was trying to tell us something. And then it flew out during a match.

We eventually settled upon the theory that the C ring holding the shaft in place had become worn or weakened. We replaced the ring with one from a soare VP case when putting it back together and it went for another 2.5 events.

It was frustrating knowing that it could do that. For a case that disassembles so easily just didn't make sense that a better design that prevented that from happening could not have been used. But like others, I agree that the output end to the VP gearbox is severely underutilized from a design and function perspective. There is a lot of potential there. Longer shafts, angled output, greater variability of shaft lengths, etc. I could even imagine a U transfer case directing the output back towards the motor for space critical uses.

Munchskull

14-05-2016, 01:24

It was frustrating knowing that it could do that. For a case that disassembles so easily just didn't make sense that a better design that prevented that from happening could not have been used. But like others, I agree that the output end to the VP gearbox is severely underutilized from a design and function perspective. There is a lot of potential there. Longer shafts, angled output, greater variability of shaft lengths, etc. I could even imagine a U transfer case directing the output back towards the motor for space critical uses.

Flex shafts!

IronicDeadBird

16-05-2016, 15:39

How would different colors fix anything? Unless you had to boost the pre-color production to meet a MOQ, that doesn't change the quantity available (and even then, it creates more SKUs for vendors to have to pore over).

Cause some people are OCD enough to not buy some things because they want things to match.

adciv

16-05-2016, 16:25

Cause some people are OCD enough to not buy some things because they want things to match.

Actually, we're CDO. The letters are alphabetized as they're supposed to be.

Chris is me

16-05-2016, 16:29

One more thing I thought of: A VP 1:1 stage. Yeah I know you can directly hook the gearbox up to achieve this, but I'm talking about something you can drop in to replace an existing stage. Sometimes you go from 2 reductions to 1 reduction, but you want to use the same mounting holes, and a 1:1 spacer stage would be good for this. Using an encoder stage for this gets pricey. :)

I was wondering how long it was going to take before someone got around to this. It's unreasonable and somewhat silly to try and turn a VP into a low RPM high torque wervo. They aren't reqlly designed for that.

They definitely are! The BAG motor with a 100:1 reduction is awfully reminiscent of the old Globe motors that used to be in the kit. They can handle the torque.

happyWobot

16-05-2016, 23:52

They definitely are! The BAG motor with a 100:1 reduction is awfully reminiscent of the old Globe motors that used to be in the kit. They can handle the torque.

Never said you can't use a VP or configure it to do servo tasks. But a two stage VP and Bag motor is unreasonably long and still only gets you to 140rpm. What if you want 15-40 rpms? I have to attach a mini-cim to a 100:1 config just to get it to 62rpm at full power. For a simple high power/ low rpm servo, thats just an unreasonably heavy config and in most cases its unmountable if your trying to use it to drive an elbow on a multistage arm. A highly compact high torque, non-pneumatic, low rpm servo is sorely missing in the FRC toolkit. Window motors are highly underutilized for this task because there is no standardized means to connect it to other things with reliability.

BTW, the single stage 1:1 is a great idea. We ran into the same issue needing to refab the mount in order to convert from 1:1 to 4: 1. The same thought occurred to me. Why wasnt there an internal extension to enable 1:1 in a single stage case.

jwfoss

07-06-2016, 11:05

Some offseason designs, and our limited in house capabilities leave us wishing for 1/2" hex stock with a pilot bore (aka Thunderhex minus the rounded corners).

Max Boord

07-06-2016, 11:27

Some offseason designs, and our limited in house capabilities leave us wishing for 1/2" hex stock with a pilot bore (aka Thunderhex minus the rounded corners).

Can you provide an example where the rounded corners make thunderhex shaft inferrior to regular hex shaft? Also thunderhex bearings alone should be enough of a reason to use thunderhex over Regular hex.

Michael Hill

07-06-2016, 15:00

Can you provide an example where the rounded corners make thunderhex shaft inferrior to regular hex shaft? Also thunderhex bearings alone should be enough of a reason to use thunderhex over Regular hex.

We had a small issue this year. We were using the cheap-o plastic Vex hubs with thunderhex shafts in the front and back (6-wheel drive, center wheel had regular hex). We had 8" pneumatic wheels on a 16:1 ratio. We noticed the thunderhex shaft was rounding out the hubs. I think it was a combination of the plastic hubs, thunderhex, and high torque at the wheel axles. We took care of the problem by switching to the aluminum hubs and regular hex and saw no more problems. I couldn't tell you which one solved the problem, whether we would have had the same issues with regular hex with the plastic bores (possible) or the thunderhex with aluminum hubs (not likely).

The problem was not strictly with the thunderhex shaft, but in that particular application, using regular hex shaft would have possibly not worn out the plastic hubs (or at least would have delayed the problem).

Knufire

07-06-2016, 15:21

We had a small issue this year. We were using the cheap-o plastic Vex hubs with thunderhex shafts in the front and back (6-wheel drive, center wheel had regular hex). We had 8" pneumatic wheels on a 16:1 ratio. We noticed the thunderhex shaft was rounding out the hubs. I think it was a combination of the plastic hubs, thunderhex, and high torque at the wheel axles. We took care of the problem by switching to the aluminum hubs and regular hex and saw no more problems. I couldn't tell you which one solved the problem, whether we would have had the same issues with regular hex with the plastic bores (possible) or the thunderhex with aluminum hubs (not likely).

The problem was not strictly with the thunderhex shaft, but in that particular application, using regular hex shaft would have possibly not worn out the plastic hubs (or at least would have delayed the problem).

I think the official VEX recommendation is using a metal hub on one side (to transmit the torque) and a plastic on the other side to support the wheel.

http://i.imgur.com/Ej9OvcU.png

marshall

07-06-2016, 15:43

I think the official VEX recommendation is using a metal hub on one side (to transmit the torque) and a plastic on the other side to support the wheel.

http://i.imgur.com/Ej9OvcU.png

We had a similar issue and cracked the plastic hubs. Some very nice people with crazy pants on Team 1296 helped us out with some aluminum replacements. Reading that note on the Vex site is important.

Michael Hill

07-06-2016, 16:07

I think the official VEX recommendation is using a metal hub on one side (to transmit the torque) and a plastic on the other side to support the wheel.

http://i.imgur.com/Ej9OvcU.png

I've never noticed that. Thanks for pointing it out. I knew you could get by with a single aluminum hub. I guess I misunderstood the purpose of the plastic one. In all honesty, they could just sell a plastic part with no versahub, just a mock bearing and it would work fine (and be cheaper to make).

Michael Hill

07-06-2016, 16:10

Basically a plastic version of this: http://www.competitionrobotparts.com/shop/drum-rollers/1-25in-diameter-roller-end-cap/ with a 1.125" OD.

Gregor

07-06-2016, 16:30

Basically a plastic version of this: http://www.competitionrobotparts.com/shop/drum-rollers/1-25in-diameter-roller-end-cap/ with a 1.125" OD.

http://www.andymark.com/product-p/am-1305.htm

Kevin Ainsworth

07-06-2016, 17:29

The attached gear was pocketed on each side .112, leaving a web thickness of .150.

Maybe leaving a little more meat by the gear teeth so you don't have a stress riser that can propagate to the thin web. We leave a 1/4" from the outside of the teeth to the OD of the undercut with about a 3/16" chamfer that cuts into the teeth slightly.
It looks like the broken gear has about 1/8" from the outside of the tooth to the undercut with about a 1/16" chamfer.

I also want Vex steel gears in 3/8" and 1/2" hex bores, 30 teeth and smaller.
We like to make the smaller gear steel and the larger gear aluminum. Aluminum on aluminum tends to wear out prematurely. Especially for the practice robot that gets much higher wear than the comp bot.

-4"x1.5" and 4"x2" Aluminum Wheels with 1/2" Hex Broach
-Anti-backdrive stage for VersaPlanetary
-Disc Brake set up with 1/2" Hex or "Standard" Sprocket Hole Pattern

Anti-backdrive and a disc brake add-on for 1/2" hex stock would be a great addition.

I would like to see a ratcheting gear and pawl. It would be nice if the ratcheting gear had a 1/2 inch hex broached bore.

Option B would be a ratcheting gear with the standard FIRST bolt circle to attach to a hub.

Dido on the ratchet and pawl for a 1/2" hex bore. We modified McMaster ones for both our winch and climbing mechanism this year.

AdamHeard

07-06-2016, 17:33

Maybe leaving a little more meat by the gear teeth so you don't have a stress riser that can propagate to the thin web. We leave a 1/4" from the outside of the teeth to the OD of the undercut with about a 3/16" chamfer that cuts into the teeth slightly.
It looks like the broken gear has about 1/8" from the outside of the tooth to the undercut with about a 1/16" chamfer.

I'm pretty certain we actually failed that gear on the hex as it was pocketed way too close to the shaft.

there is actually a decent amount of material under the teeth based on what we've had work in the past.

Michael Hill

07-06-2016, 18:21

http://www.andymark.com/product-p/am-1305.htm

Wow! Andy's quick!

Chris is me

07-06-2016, 18:35

I also want Vex steel gears in 3/8" and 1/2" hex bores, 30 teeth and smaller.
We like to make the smaller gear steel and the larger gear aluminum. Aluminum on aluminum tends to wear out prematurely. Especially for the practice robot that gets much higher wear than the comp bot.

I've never had an aluminum gear "wear out". I've broken aluminum gears, I've run aluminum gearboxes for hundreds of hours on practice robots, but I've never had a gear "wear out". I'm sure you guys are properly greasing your gearboxes and taking all of the right steps for maintenance, so I'm really curious to see what your failures look like?

Tal_Esh

07-06-2016, 18:58

Not sure if was mentioned before but:

-2" omni and meccanum wheels, those are quite hard to find
-custom 971's-like roborio connections board
-more bevel gears

Chak

07-06-2016, 19:04

-custom 971's-like roborio connections board

you mean this (http://www.wcproducts.net/sensors)?

Knufire

07-06-2016, 19:05

-custom 971's-like roborio connections board

This was designed by 971: http://www.wcproducts.net/catalogsearch/result/?q=spartan

Michael Hill

07-06-2016, 20:52

Not sure if was mentioned before but:

-2" omni and meccanum wheels, those are quite hard to find
-custom 971's-like roborio connections board
-more bevel gears

http://store.kornylak.com/SearchResults.asp?Cat=20

We rolled the RW640s in 2015 for sideways motion initially. Didn't quite work out in that application (too slick). But 118 likes to use them for other applications. Check out the transwheels as well for light loading http://store.kornylak.com/SearchResults.asp?Cat=3

Tal_Esh

08-06-2016, 00:11

Didn't know it is being sold, greath news :P

Mk.32

08-06-2016, 07:22

-4"x1.5" and 4"x2" Aluminum Wheels with 1/2" Hex Broach
-Anti-backdrive stage for VersaPlanetary
-Disc Brake set up with 1/2" Hex or "Standard" Sprocket Hole Pattern

Discs brake you want eh?
https://electricscooterparts.com/discbrakes.html

I learned that BRK-512 works with BRK-480L and has a hole pattern that is close enough to work with the AM 1.875in hole pattern with number 10s.

jwfoss

08-06-2016, 07:47

Discs brake you want eh?
https://electricscooterparts.com/discbrakes.html

I learned that BRK-512 works with BRK-480L and has a hole pattern that is close enough to work with the AM 1.875in hole pattern with number 10s.

Thanks for the heads up, did you also buy the caliper from the same company? If so which one, and do you have any images of integration into your robot? Thanks!

Monochron

08-06-2016, 10:01

Thanks for the heads up, did you also buy the caliper from the same company? If so which one, and do you have any images of integration into your robot? Thanks!

Seconding!

Greg Needel

08-06-2016, 10:29

Seconding!

We used a mechanical brake this year, and had good success integrating one like this onto the robot. https://www.ombwarehouse.com/universal-disc-brake-caliper.html

We actually just used a sprocket as the disk without problems.

Brandon Holley

08-06-2016, 11:53

Dido on the ratchet and pawl for a 1/2" hex bore. We modified McMaster ones for both our winch and climbing mechanism this year.

Boom.

http://www.armstrongtools.com/MagentoShare/media/catalog/product/cache/5/image/1200x1200/9df78eab33525d08d6e5fb8d27136e95/A/R/ARM_54-110_FRNT_MAIN_8.jpg

-Brando

Ryan Dognaux

08-06-2016, 11:54

Discs brake you want eh?
https://electricscooterparts.com/discbrakes.html

I learned that BRK-512 works with BRK-480L and has a hole pattern that is close enough to work with the AM 1.875in hole pattern with number 10s.

We've also used disc brakes for the past 2 seasons. It was extremely helpful in 2015 for holding our elevator's position without stalling motors.

I'm about 99% sure we purchased this kit from Amazon - https://www.amazon.com/Signswise-Mountain-Bicycle-Mechanical-Rotors/dp/B011704A48/ref=sr_1_3?ie=UTF8&qid=1465400884&sr=8-3&keywords=disc+brake Came with 2 disc brakes and 2 caliper kits. Great for a practice bot and competition bot setup.

The hole pattern was close enough to get 3 or 4 bolts aligned to mount a 1/2" hex hub. We used a small pneumatic actuator to pull the caliper's brake cable, worked great. You can see a video of it here (https://youtu.be/JrebWdH8x4c?t=2s).

Mk.32

08-06-2016, 17:54

Thanks for the heads up, did you also buy the caliper from the same company? If so which one, and do you have any images of integration into your robot? Thanks!

I have listed both model numbers for the disk and caliper: BRK-512 and BRK-480L. You should find both parts on the website. The caliper uses a regular old bike cable.

Heh.. ironically this was an happy accident. As I did not buy these parts for FRC but for a gokart I race at makerfaires (us mentors gotta have something to build in the off season). And I used AM tires for the front, and realized that everything lined up nicely so it saved me the trouble of making an adapter hub.

You can also make your own disks to if you have basic milling abilities, take piece of .09 flat stock and drill the holes you want into it. You do not need any of the fancy cutouts and speed holes/etc of the commercial disks. Just need the stock to be flat.

Mike Schreiber

08-06-2016, 21:55

Yes I have. Generally I've been very pleased with the VP. Through 4 events they held together running a shooter that worked outside the robot perimeter. They took unbelievable punishment. But they have one potential flaw. We saw the shaft fly out of the VP twice this whole season. Mind you right before the second time the case was making a rattle we couldn't identify. It was trying to tell us something. And then it flew out during a match.

We eventually settled upon the theory that the C ring holding the shaft in place had become worn or weakened. We replaced the ring with one from a soare VP case when putting it back together and it went for another 2.5 events.

It was frustrating knowing that it could do that. For a case that disassembles so easily just didn't make sense that a better design that prevented that from happening could not have been used. But like others, I agree that the output end to the VP gearbox is severely underutilized from a design and function perspective. There is a lot of potential there. Longer shafts, angled output, greater variability of shaft lengths, etc. I could even imagine a U transfer case directing the output back towards the motor for space critical uses.

I've seen this occur because the snap ring is over stretched when being installed. It is easy to deform these if you're not careful. Don't open up your pliers too far, just the bare minimum to clear the spline, this should ensure a nice fit when they spring back.

Michael Hill

08-06-2016, 22:26

The spline is a separate piece. The shaft and spline are combined with a dutch key. I almost did this last season: Press out the shaft and insert a new one and drill in a new hole for the dutch key.

Do you have any pictures of this? I looked at our VP output shafts and couldn't find anything that resembled this. Maybe I'm just blind.

Mark Sheridan

10-06-2016, 18:53

Do you have any pictures of this? I looked at our VP output shafts and couldn't find anything that resembled this. Maybe I'm just blind.

http://www.vexrobotics.com/217-2894.html

You can see it in this picture. There are two dowel pins used as keys, thus making them dutch keys. 100% of mine look like this but our shafts were sourced from 2013, 2014 and 2015. Its not a published spec, so vex could have another revision that is not made this way. We found a way that avoided taking apart this feature, i am not sure how hard it is. I used the dutch key professionally as an emergency reinforcement of key way, they were not drilled straight so once the dowel pins were inserted, we knew it has really hard to take apart thus threw away the assembly when there was down time.

Michael Hill

10-06-2016, 20:42

http://www.vexrobotics.com/217-2894.html

You can see it in this picture. There are two dowel pins used as keys, thus making them dutch keys. 100% of mine look like this but our shafts were sourced from 2013, 2014 and 2015. Its not a published spec, so vex could have another revision that is not made this way. We found a way that avoided taking apart this feature, i am not sure how hard it is. I used the dutch key professionally as an emergency reinforcement of key way, they were not drilled straight so once the dowel pins were inserted, we knew it has really hard to take apart thus threw away the assembly when there was down time.

Wow, ours don't look like that at all. Our's have a continuous back side, but there's a small hole in the middle.

Aren_Hill

10-06-2016, 21:17

Wow, ours don't look like that at all. Our's have a continuous back side, but there's a small hole in the middle.

It does depend on the shaft, the 1/2" hex shaft does not have this as it is machined from solid, same for the 1/2" round. But the 3/8" and 8mm shafts are two piece units.

-Aren

Michael Hill

10-06-2016, 21:54

It does depend on the shaft, the 1/2" hex shaft does not have this as it is machined from solid, same for the 1/2" round. But the 3/8" and 8mm shafts are two piece units.

-Aren

Makes sense. That's exactly what I was looking at. I think we've got an 8mm output shaft somewhere I'll have to check out. Thanks!

DonRotolo

11-06-2016, 15:42

tl;dr

A good elbow joint, using most any motor, light and under $400. That woud be a great COTS part.

Lil' Lavery

19-09-2016, 11:38

Chris is me

19-09-2016, 11:42

It's probably too late for this, but I'd be really happy if there were COTS 32mm wide HTD pulleys available from Vex. Right now if you run double 15s you need two separate 18mm pulleys, and that's just annoying. I don't like making pulleys from stock. Would be best if we could just buy 'em. 9mm wide belts in the drive is often pushing it anyway.

Oblarg

19-09-2016, 13:02

AdamHeard

19-09-2016, 13:04

Taper-lock (http://cmtco.com/maxitorque.html) hubs.

I found some HTD pulleys using this style of bushing lying around our shop last year, and they're basically the most convenient thing ever. If FRC suppliers could start making stuff that uses this in lieu of set-screws, it'd be very nice.

We use these on keyless bushings a lot in industry (more often keyless bushings).

Clamping interfaces are a great way to do things, but I'm unsure if they'd come in cheap enough for the average FRC customer.

Would love to get them though!

nuclearnerd

19-09-2016, 13:20

marshall

19-09-2016, 15:00

I love this thread. I thought of another since my last suggestion:
Gearboxes with hex-bore 3rd stages. Imagine how much easier replacing a gearbox would be if you could leave the drive train all connected and just slip the gearbox off the final drive shaft?

We've been kind of doing that for a few years with the AM ToughBoxes and using the same style of mounting that the kit chassis uses. You can pull the gearbox without pulling the drivetrain with it. Kind of nice.

That being said, the ability to place any arbitrary 1/2" hex output shaft would be nice.

Oblarg

19-09-2016, 15:06

I love this thread. I thought of another since my last suggestion:
Gearboxes with hex-bore 3rd stages. Imagine how much easier replacing a gearbox would be if you could leave the drive train all connected and just slip the gearbox off the final drive shaft?

I designed (and 4464 constructed) a gearbox like this a couple years ago, and it was indeed fairly convenient. The only problem is that it is less-conducive to WCD-style drives, since you need to support the output shaft separately.

nuclearnerd

19-09-2016, 21:19

I designed (and 4464 constructed) a gearbox like this a couple years ago, and it was indeed fairly convenient. The only problem is that it is less-conducive to WCD-style drives, since you need to support the output shaft separately.

Why would that be difficult? Center wheel supported by hex shaft in bearing blocks, same as per wheels. Hex bore gearbox then slips over hex shaft on the inside of the frame.

If you're really clever, you could put the gearbox on a fourth jack shaft between wheels, and reverse the mounting so that the mounting bolts are accessible, and the gearbox slides off the shaft outward from the frame, same as the wheels. That would be amazing!

GeeTwo

19-09-2016, 21:47

VexPro gussets (namely t-gussets) with the pre-drilled holes aligned at a 1/2" offset. Right now the t-gussets support aligning versa frame rails to each other ever 1", but having a gusset option like this would allow alignment options every 1/2". Obviously there are many easy workarounds to achieve the same end result with existing products, but "native" support of those configurations would be useful.

??
Both the VersaFrame T gusset and the VersaChassis gussets have holes every 1/2". Did you mean a 1/4" offset?

A tool to punch holes in tread for the alligator clips would be great - we mangled about a quarter of our clips, and half of the other three-quarters aren't quite right. The ideal form of this tool would have a ledge for the setback and small hole punches (not awls) to make the holes.

A miter box for versaframe to help put the hacksaw exactly where it should be for square, 30 degree, 45 degree, and 60 degree miters.

VF Gussets for 37 degree and 53 degree angles (that is, the acute angles of a 3-4-5 triangle). And a miter box for that, too.

Oblarg

19-09-2016, 23:03

Why would that be difficult? Center wheel supported by hex shaft in bearing blocks, same as per wheels. Hex bore gearbox then slips over hex shaft on the inside of the frame.

If you're really clever, you could put the gearbox on a fourth jack shaft between wheels, and reverse the mounting so that the mounting bolts are accessible, and the gearbox slides off the shaft outward from the frame, same as the wheels. That would be amazing!

It's certainly doable, but it's not nearly as trivial as simply bolting the gearbox in place as is done in an ordinary WCD (you have to leave space for the second bearing and whatever hex bore coupler you're using as an output).

nuclearnerd

20-09-2016, 03:02

[QUOTE=Oblarg;1607585(you have to leave space for the second bearing and whatever hex bore coupler you're using as an output).[/QUOTE]

No that's just the thing. I don't want a coupling, I want a hex bore all the way through the gearbox, supported by internal bearings, so it is just a bolt-on operation.

marshall

20-09-2016, 07:31

A tool to punch holes in tread for the alligator clips would be great - we mangled about a quarter of our clips, and half of the other three-quarters aren't quite right. The ideal form of this tool would have a ledge for the setback and small hole punches (not awls) to make the holes.

We gave up on those aggravating clips years ago and switched over to rivets... which come with their own problems but we find them easier than the clips to deal with.

Oblarg

20-09-2016, 07:35

No that's just the thing. I don't want a coupling, I want a hex bore all the way through the gearbox, supported by internal bearings, so it is just a bolt-on operation.

Still need to leave room for the second bearing on the output shaft, though.

GeeTwo

20-09-2016, 20:42

We gave up on those aggravating clips years ago and switched over to rivets... which come with their own problems but we find them easier than the clips to deal with.

What wheels do you use, and what size (bore and length) rivets? Which style tread is this with?

At the end of Red Stick Rumble, we wound up wiring the (pebble top) tread on with steel wire wrapped around the wheel and tread in about six places, which seemed to work better than anything we had done all season. Failing a good way to secure clips, we were already planning that in a situation like this year we would go with "solid rubber" wheels (e.g. colsons, or kit wheels from 2010, 2015, or 2016), and carving tread if needed, or the wiring solution. We'll have to try some rivets.