CIMcoder: Encoder Mount

[Munchskull]

Originally Posted by pilleya

Fantastic design, this will work very well with Versa-planetary CIM input adaptors, just less shaft to cut off.

I confirm that this will not work with WCP Dog shifters, due to the CIM gear-first stage, meshing at the end of the shaft.

After about an hour of trouble shooting and math, I developed a new mount that works an the WCP DS Gearbox. The one catch is you have to use an Andymark 12t pinion gear (or any pinion gear that is 0.52" or less).

[nuclearnerd]

Originally Posted by Munchskull

After about an hour of trouble shooting and math, I developed a new mount that works an the WCP DS Gearbox. The one catch is you have to use an Andymark 12t pinion gear (or any pinion gear that is 0.52" or less).

Looks nice!
Note that using your encoder mount on a shifting gearbox like the WCP DS will mean you won't be able keep track of actual distance travelled after shifting.

[Munchskull]

Originally Posted by nuclearnerd

Looks nice!
Note that using your encoder mount on a shifting gearbox like the WCP DS will mean you won't be able keep track of actual distance travelled after shifting.

Correct me if I am wrong but couldn't you use a true-false variable to determine if you were in the high or low gear? Then from there you could a just the way your code reads the encoder.

[R.C.]

Originally Posted by Munchskull

Correct me if I am wrong but couldn't you use a true-false variable to determine if you were in the high or low gear? Then from there you could a just the way your code reads the encoder.

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.

[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.

[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.