The thread Encoders got me thinking. We are currently building our first WCD type chassis with shifting gear boxes. There seems to be some discussion on the negative to putting the encoders on one of the intermediate stages of the gearbox with the mounting locations supplied. Has anyone considered mounting an encoder similar to a CIMcoder or AMT103-V kits on the axle? It would be a nightmare to work on but if your not using the inside of the tube for chain there is a <1" of unused shaft there to use a hollow shaft encoder. Or build it right into this thing.
Even Beyond WCD Chassis there would be uses to encode mid shaft vs all ways finding ways to mound at the end.
There’s not really any appreciable advantage to putting the encoder on the output of the gearbox vs mounting it on one of the other wheel shafts, as many teams do. It’s a lot easier to do (can just drill a .25" hole) and to maintain / access.
We did our first WCD chassis last year, and ended up mounting some Grayhill encoders on one of the non-gearbox shafts. It was pretty straight forward to build a mount to hold the encoder approx in line with the shaft, and connect it to the shaft with some surgical tubing (accounts for any misalignment). We are always looking for better ways, though!
I’m looking for through shaft encoders. These adapters look like it would only get you end of shaft coupling. Still a interesting way to use products you may already have for a use not originally intended.
I’ve fantasized about a through shaft hex bore encoder for a long time. We’d use the heck out of it.
Modifying the versaplanet is too expensive and heavy for my liking.
I’d also like it fully supported on its own small bearings so that it can be placed floating on a shaft, and literally tapes,glued or zip tied to something rigid.
Paging CTRE, Vex, and AM (or others). We’d probably jump in line for this too provided it is more closely related to the CTRE Mag encoder than to to the CIMCoder.
I can definitely see the appeal of a product like this. Something that’s basically plug and play, no ulta precise positioning required would be a huge benefit. Heck, you could even match drill the mounting holes in place with a hand drill if you felt zip ties or tape wasn’t robust enough.
There’s definitely been a lot of progress on the front of making encoders more accessible what with gearboxes coming standard with encoder mounting options, and of course the VP encoder, but neither of those is appropriate for all applications in FRC.
With regard to the OP’s original question about encoders on a WCD chassis, I would have to agree with previous comments that it is far easier to mount the encoder on the other wheel shafts. We have done this for the past few years and it works well. We mount a CTRE Mag encoder on a 3D printed mount that spaces the encoder properly and machine our wheel shafts to accept the magnet for the encoder (similar to how it is shown in the user guide).
Personally I have always felt that every robot needs a minimum of wheel encoders and a gyro to enable basic autonomous. While there are other ways to measure distance, encoders are simple and relatively cheap.
I just finished probing the web for multi poll ring magnets to maybe try and create a solution. I found Phoenix American Magnetic Encoder solutions. Turns out they make the CIMCoder already.
Last time I checked, CTRE did not see a demand for a hex bore encoder. They don’t check CD too often, so sending them an email will be vastly more effective than posting here.
Looks like many are having success with 3D printed variations. Maybe a revisit to plastic components is worthy. It doesn’t need to be industrial like the pictures make it look. Plastic hex interface with plastic housings might just cut it.
