pic: Fun 3 CIM Shifter Idea

[Kevin Ainsworth]

Are you running both gears on the CIM shaft directly? This will be almost impossible to achieve due to clocking all the gears. Imagine two CIM gears and two shifting gears, no problem the shifter gears will rotate into position. Add one more motor with a single gear and that second motor will be free to rotate into position. Add a second gear on that second motor and now your clocking for that second gear is based on its alignment to the first gear. You now need the second motors gears to align properly to each other to engage the two larger shifting gears without interference. Adding a third motor makes it impossible if you are using luck. We had issues with two motors doing this in 2013, luckily we were using hex shaft adapters coming off the CIM shafts so we had six different alignments to try per motor. I can only imagine the trouble three motors would cause. This could work if you were to wire EDM the gears or fixture the gears while broaching in the key slot or hex shape. In larger applications you could use a taper lock keyless bushing so that you could line up the gear teeth and then lock down the gear to the shaft, but there would be no room for this with an FRC gearbox. I just want to educate everyone about this method of gearbox design where the CIM motor has two gears on it and the potential issues you might encounter.