What COTS parts would you like to see?

[mklinker]

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]

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

[Knufire]

Originally Posted by maxnz

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]

Originally Posted by Knufire

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.

[Knufire]

Originally Posted by maxnz

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.

Originally Posted by waterwaterwater

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]

Originally Posted by Knufire

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. For whatever reason, (Not a web developer so can't tell you why, AM's links require the .htm at the end.

[maxnz]

Originally Posted by Knufire

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]

Originally Posted by maxnz

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.

[nuclearnerd]

Originally Posted by maxnz

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/sh....php?p=1569705

[ratdude747]

Originally Posted by FrankJ

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).

[Kevin Ainsworth]

Originally Posted by AdamHeard

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.

Originally Posted by jwfoss

-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.

Originally Posted by mklinker

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]

Originally Posted by Kevin Ainsworth

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.

[Chris is me]

Originally Posted by Kevin Ainsworth

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]

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]

Originally Posted by Tal_Esh

-custom 971's-like roborio connections board

you mean this?