pic: 3 cim 2 speed ball shifter w/ external pto

[Dylan179]

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[asid61]

Very interesting design, quite compact. The 3-cim design is unique in the age of the RoboRIO as well.
Have you thought about swapping the hex bearings to 3/8" round flanged bearings with the flange on the inside of the gearbox? That's a pretty common technique for gearboxes.
What shifter shafts are you using? What is the weight of the gearbox? Why is your gear ratio spread so low?

[Chak]

Nice! That looks like it's as small as possible while still having 3 CIMs and PTO.

How do you plan on mounting the gearbox? I see 3 holes near the bottom, but 2 of them are #10 screws that also have to go through the CIM, and the third looks just a bit too high. Maybe you'll have to make your gearbox plates slightly larger for more mounting points.

Assuming this is for WCD, how are the sprockets going to go on? Mostly I've seen them inside the gearbox, and that would make this gearbox wider. I guess your gearbox is too small!

How do you do the hex sleeve thing for the output? I've heard to mentioned before and tried to imagine it, but what's the "normal" way of doing it?

[hectorcastillo]

Very Cool! Did you design the PTO for a specific purpose in mind? Also, do you have a plan for mounting the pneumatic cylinder for shifting?

[Chris is me]

The ratio is a little tight I think, 13 FPS is a smidge slow for a shifting gearbox and 8 FPS is pretty fast for a low gear. How much current are you drawing in a pushing match? You could risk a main breaker trip depending on the current draw of the rest of your robot and how long you are pushing.

[Dylan179]

It's mass is 11.19 lbs as is but it is probably closer to 13 lbs w/ shafts and fasteners.

I am using the vexpro v2 ball shifter shafts.

The pistons aren't hard to mount its just 2 holes and standoffs, they have plenty of space for both of them.

For the speed, I am assuming that this new field is not going to be flat because i like comparing things to 2012's field where you never got to full speed anyways if you had a high ratio gear box.

"Have you thought about swapping the hex bearings to 3/8" round flanged bearings with the flange on the inside of the gearbox?" (asid61)
Good idea, noted.


"How do you do the hex sleeve thing for the output? I've heard to mentioned before and tried to imagine it, but what's the "normal" way of doing it?" (Chak)
If you are referring to how to change the shaft, there is a roll pin than can be removed to change the output shaft.