Substitutions for Neo key

Our team needs to find a way to create a substitute key for a Neo without buying one. Do you have any suggestions? Thanks!

Which type of neo key? There’s a couple types, the cim style key or do you mean the ones used in MaxSwerve?

The (REV-21-3005-P10-PK3) are the ones from the MaxSwerve kit and can be ordered as spares MAXSwerve Spare Parts - REV Robotics and would be tricky to make on your own

The regular CIM style keys are just 2mm x2mmx10mm pieces of metal laid in the track on the neos shaft. These are easier to make and source 2 x 2 x 10 mm Machine Key - AndyMark, Inc

It’s just the cim style key, but we need it very soon and don’t have access to any machining equipment

Got any old CIM motors put into a “KitBot” Am14U gearbox? Those require at least two motor keys per gearbox. Otherwise you’re looking for 2mmx2mm stock which is close to 5/64 inches. Most hardware stores stop at 5/16 as the smallest they have in house. So then it’s a special order. I got lucky and found a key stock set at Harbor Freight once

Good call.

@theovandermarck - You could go from 5/16 stock as suggested to 5/64 pretty quick with a file. You could even start with a small screw and file that square. If you can buy a piece of metal and a file, you can make this happen.

In a pinch a small nail can get the job done… though it may damage the motor shaft and/or gear.

McMaster also has 2mm keys:

Thank you all for your help. In the end we settled on cutting apart a 5/64 alan key which is currently working.


Pocketing this info for later. That’s a great fix in a pinch, let us know how it holds up over a longer term. I’d be worried about the hex v square shaped but if it’s working don’t question it.

Will do!

Buy a 2mm drill bit and break it off to length. Should be OK-ish in a pinch.

I did that to couple my bike’s cim to its gearbox and so far it hasn’t taken any obvious wear

We used the left-over tail of a pop-rivet (after we used the rivet). Wouldn’t recommend for heavy duty but worked in a pinch.

Update: We showcased the bot for a weekend, running all of the motors and subsytems at full speed, and it’s held up very well! We haven’t physically checked on it, but it seems to be perfectly fine. We will definitely be doing this if we’re in a pinch at a comp (although knowing the FRC community I doubt it would be hard to find one to borrow).


A 10-32 screw will also fit in a 5mm keyway. I wouldn’t expect long life or high torque out of it, but it’ll do in a pinch.