Re: What COTS parts would you like to see?
 

It seems like that would be much more expensive than just making a lightened steel one, however I can't comment on the strength.

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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).

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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/sh...d.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.

Re: What COTS parts would you like to see?
 

I want a CAN plug-in vision aiming module

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.


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


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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

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

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

A bigger version of the versaplanetary.

Re: What COTS parts would you like to see?
 

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

1. 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!
2. 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
3. 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
4. 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
5. 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
6. Longer ribbon cable for talon SRX's, and/or cheaper breakouts

I'll probably come up with more...

Re: What COTS parts would you like to see?
 

Hmm, I generally really like this one...

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

Why not just use the male 1/2" hex output shaft and one of these 217-4008?

Re: What COTS parts would you like to see?
 

Its a matter of form factor.

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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?

Re: What COTS parts would you like to see?
 

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

Flex shafts!

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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. :)

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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).

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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).

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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).

Re: What COTS parts would you like to see?
 

Basically a plastic version of this: http://www.competitionrobotparts.com...oller-end-cap/ with a 1.125" OD.

Re: What COTS parts would you like to see?
 

Re: What COTS parts would you like to see?
 

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.

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

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

Wow! Andy's quick!

Re: What COTS parts would you like to see?
 

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?

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

you mean this?

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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!

Re: What COTS parts would you like to see?
 

Seconding!

Re: What COTS parts would you like to see?
 

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


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

Re: What COTS parts would you like to see?
 

Boom.




-Brando

Re: What COTS parts would you like to see?
 

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-Mou...rds=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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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!

Re: What COTS parts would you like to see?
 

tl;dr

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

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

Taper-lock 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.

Re: What COTS parts would you like to see?
 

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!

Re: What COTS parts would you like to see?
 

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?

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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!

Re: What COTS parts would you like to see?
 

??
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.

Re: What COTS parts would you like to see?
 

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).

Re: What COTS parts would you like to see?
 

[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.

Re: What COTS parts would you like to see?
 

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.

Re: What COTS parts would you like to see?
 

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

Re: What COTS parts would you like to see?
 

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.