Lower profile shaft collar alternative

As you can see, the shaft collar in this spot hits the wheel, because 2.75" wheels are weirdly sized. Does anyone know of any lower profile shaft collar alternatives for low strength shafts, other than shaving the shaft collar down (which I’d prefer not to do)?


Try using a capped shaft.


And before anyone mentions them, rubber shaft collars also don’t fit, and I wouldn’t trust them in this spot.

Unfortunately won’t work, I need to stop the gear from sliding on the shaft.

I’m not following you on the sliding on the shaft issue. The cap at the end of the shaft will prevent the gear from sliding towards the wheel if the cap is on that side.


You would still need a shaft collar on the other side of the c-channel that the motor is mounted to.

One issue you are likely to have is that the gear will slip. This would happen even if a normal shaft collar fits because the shaft is not supported on both sides.

Is it possible to run the shaft all the way across to the other c-channel?


Try to hammer the end of the shaft and put that gear in from the other side.

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Oh sorry, I forgot to put in the shaft in the cad lol.

I need the shaft to run all the way across to the other c-channel.
I think the gear would skip to easily if I just did a cantilevered capped shaft, but I could probably try it, I think we have some.

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What I would personally try is like scoring the shaft, scratching it up on the exact spot you need the gear to stay on, so it won’t slide.

Don’t know if it would work, or what downsides it may have but just a thought.


Would potentially using some small OD spacers (or shaving down spacers if that’s more preferable to shaving down shaft collars) across the shaft work in this situation?


You could bore a hole in the 24t gear deep enough that the shaft collar is recessed but you can still access the set screw. Not sure that is enough to avoid the conflict, probably 1/16 or 3/32 recess.


You could also use a die to thread the end of the shaft and use a nylock


So unconventional way of thinking about it, but what if you wrapped some thing around the gear on the outside.

You would probably want to have some lube for it to work. You could make it out of poly or even a screw and washer/spacer. I what I have said is very unconventional, and there are other ideas like low profile spacers that you should try first.

ALSO are you using the new wheels or the old ones as that could make a difference.


Scuff up the part of the shaft that the gear goes on. I have used both a die and a center punch for this type of thing but both work. You will need to hammer the gear into place, but once you do, it won’t come off unless you hammer it off.

Another, more “proper” solution would be to use a c-clip (not a vex part but it is legal cause it’s really just a washer and could be machined out of a vex washer)


You’d need to make a slot in the shaft but once you did it would be pretty secure. Not sure I prefer this to just scuffing up the shaft but both work.


Okay, thanks for all the replies. I’ll probably try some of these methods later, will report back what works for me.


Do you have to place the collar directly on the gear? What’s stopping you from putting the collar on the outside of the bearing on the other side? Then, to substitute the lack of a collar on the inside of the drive pod, you could put thin spacers on the axle after the 24T gear. That’s what I would do personally, unless the thin spacers wouldn’t fit.

ok, need to go through all the pinion gears and make them shaft collars. (cursed)


We did this for one of our robots

Would suggest greasing up the contacted area before putting together to reduce friction though.


something odd to try would to be to drill a hole through the shaft and thread it on the inside for a screw to just screw directly into the shaft. I think Kepler electronics did this in one of his videos.

The simply solution is to put a dog collar next to the motor (the inside part of the c channel) you would then use thin spacers and put a dog collar on the end