This year we decided to drive our mecanum wheels with a 1:5 reduction, as accomplished by using a Versa clamping single reduction gearbox.
We also did not have the machining experience to bore a shaft for the Talon SRX encoders, so we went with what seemed to be a simple installation encoder.
Enter CimCoder, the direct mount encoder for the the CIM.
I was wondering if anyone has tried this combination before, in our CAD model it looks like the clearances will be tight.
If you have used this setup:
What kind of hardware did you use for mounting the encoder to the motor? Mounting the motor to the gearbox?
Where you able to install the key and pinion gear while maintaining the correct spacing for the encoder?
I can’t comment on this specific combination, but have you considered putting a .25" hole in the end of the hex shaft and pressing a Grayhill style encoder into it directly?
If you buy ThunderHex, there is already a .201 hole, so you just need to enlarge that at one end to .25 and you should be able to put a Grayhill in there. If you are careful you may be able to do this sufficiently well without even using a lathe. If the fit is a little loose, just a touch of thin painter’s tape around the Grayhill shaft may help tighten it up.
Last year we used a vex SS, DR gearbox with the output shaft (the part on the back end of the gearbox) connected to a grayhill encoder via surgical tubing ziptied on. It worked great and was an easy way to get the encoders on their with minimal machining capabilities.
I am going to make the presumption that they mean the Andymark one. The 3D printed on I made is less than a poor choice. If I remember right I concluded you would have to weld the gear to use the one I made.
We attempted this a couple years ago and it was too painful to continue. The clamping gearbox already leaves very little room (less than 3/16") to be able to put a retaining clip on the CIM’s output shaft to hold in the pinion gear. The CIMcoder will set you back 3/8".
Therefore, retaining clips won’t work.
Most shaft collars will interfere with the 72tooth gear.
Welding works if you have the capability. (we don’t)
We tried drilling a hole through the pinion and the shaft and pressing in a roll pin, but it was too messy.
Having said all of that, we have used them successfully with small modifications for a Versaplanetary gearbox and an AndyMark Toughbox Nano.
Faced with a similar problem, I ended up trying the CUI AMT-103 encoder. The plan was milling a pocket for it, on the clamping gearbox, opposite the motor, so the stack was motor-gearbox-encoder-gear. It all fit together, but it does mean milling out a distressing amount of webbing. You have to use the 103 or you mill out even MORE webbing. We never ended up battle testing it, so I can’t guarantee the weakened gearbox won’t crumple at a hard hit, but it’s another option if you have any milling capabilities.
We developed a way to use the CUI AMT-103 encoder we got from FIRSTChoice with the Vexpro clamping gearbox. If you have access to a 3d printer we would be willing to send you the files.
