What COTS parts would you like to see?

[AdamHeard]

Originally Posted by Munchskull

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]

Originally Posted by AdamHeard

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]

Originally Posted by Chris is me

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]

Originally Posted by Chris is me

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]

1. A ball shifter with a longer output!
2. Hex gt2 pulleys

[roboruler]

Originally Posted by Munchskull

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]

Originally Posted by dv/dt

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]

Originally Posted by nuclearnerd

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

I played around with this concept around kickoff, but it got buried by other posts.

[happyWobot]

Originally Posted by AdamHeard

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]

Originally Posted by happyWobot

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]

Originally Posted by Billfred

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]

Originally Posted by IronicDeadBird

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]

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]

Originally Posted by Chris is me

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]

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).