CIMcoder: Encoder Mount

[asid61]

Originally Posted by R.C.

You would probably want to measure if the ball or dog is engaged or the change in velocity. I would recommend this over checking against a variable as shifting isn't instantaneous.

I would much rather put the encoder wheel side so you don't have to keep track of it/probably easier for repairs as well.

I feel like for most teams in most situations the minor time lag associated with shifting shouldn't affect them significantly.
I prefer having the encoders on the gearbox, as they're more protected that way. We occasionally (around once per year) lose encoders due to insufficient protection/some small mistake that destroys the already-vulnerable encoders.

[JamesTerm]

Originally Posted by BBray_T1296

When I print bolt holes I usually undersize a little and print with extra shells (maybe 4 instead of my typical 2) and then drill it out with a free fit tap drill bit. Steel machine screws easily tap themselves into the hole and make their own thread. Otherwise I will drill a clearance hole for non-threading situations.

It is generally a very easy extra operation that saves the hassle of worrying about print tolerance.

Ah that's a good approach... thanks for sharing.
I've went ahead and uploaded a little camera mounting project I did which illustrates what I do for the holes... I found on my printer to just expand the diameter by about 0.02... the threading pitch works out well enough, and I also experimented with 3D printed screws as well... not sure yet if I'll do that again, but if weight matters... it may be worth consideration.

https://grabcad.com/library/camera-m...-m1011-m1013-1

[nuclearnerd]

Originally Posted by asid61

I feel like for most teams in most situations the minor time lag associated with shifting shouldn't affect them significantly.
I prefer having the encoders on the gearbox, as they're more protected that way. We occasionally (around once per year) lose encoders due to insufficient protection/some small mistake that destroys the already-vulnerable encoders.

The more I think about it, the less I think you'd need to measure encoder values *during* shifting. We usually use encoders for auto, and it's not likely that we would shift during auto. Even if we had some sort of fancy always-on gyro compensation, we could probably disable it for a second during the shift.

Thanks for sharing!

[AustinSchuh]

Originally Posted by asid61

I feel like for most teams in most situations the minor time lag associated with shifting shouldn't affect them significantly.
I prefer having the encoders on the gearbox, as they're more protected that way. We occasionally (around once per year) lose encoders due to insufficient protection/some small mistake that destroys the already-vulnerable encoders.

We put our encoders on the gearbox, down stream of the shifting mechanism. This gives us less backlash in our measurement and we don't have to worry about shifting. The accumulated hex backlash due to the clearances that Aren specs is quite large, and the dog engagement also adds to the problem. When you are trying to design a precision autonomous mode, every little thing counts. The best way to design an awesome control loop is to have awesome hardware to control.

[marshall]

We printed one of these using our statasys. The holes for the screws for the encoder are just slightly too large to tap them for 4-40. We ended up putting a bit of glue in the hole and then taping it (READ: forcing the screw in). Worked out well.

Overall, a very nice design.

[Munchskull]

Originally Posted by marshall

We printed one of these using our statasys. The holes for the screws for the encoder are just slightly too large to tap them for 4-40. We ended up putting a bit of glue in the hole and then taping it (READ: forcing the screw in). Worked out well.

Overall, a very nice design.

Thank you. Glad that you like it. I actually believe that when I designed the encoder holes I was designing with the intention of using M3 bolts since that was what the encoder was speced for.

If you actually end up using it I would love to see pictures.

[Monochron]

Originally Posted by Munchskull

Thank you. Glad that you like it. I actually believe that when I designed the encoder holes I was designing with the intention of using M3 bolts since that was what the encoder was speced for.

If you actually end up using it I would love to see pictures.

There is a good chance this will end up on our off-season project. If it does I'll post a couple of pictures.