Nylock shaft collars + 393 motor screws

The current vex shaft collars strip so easily. I know Vex sells replacement screws in the shaft collars but if they’re stripped while all the way down, then they’re difficult to remove.

The shaft collars also slide every now and then even if they’re locked. My proposal is to make a nylock shaft collar. Similar to the nylock nuts.

Changing the internal gearing on the 393 motor is a tedious task because the screws that come with the motor strip easily. Vex should sell stainless steel motor screws for those who change the internal gearing on their motors often.

For the set screws, you can try using a metric 2.0 (it might be other sizes) hex wrench. The size should be just barely larger than the 5/64 hex wrench and it’s very useful in taking out stripped set screws.

As for the motor screws that are on the motor, I completely agree with you.

You can perhaps try to get some from the local hardware store. They should all sell them. But if there’s a stripped screw that’s on the motor, try using a bandsaw blade to score a straight mark on the screw, then using a flat head screw driver.

Also, I’ve bought different material fasteners (metal alloy, stainless, NOT chrome, even though they look beast) from a local hardware store and they all don’t strip out easily.

Lastly, in my opinion using a good hex wrench with a good end (some hex wrenches’ ends are stripped and needs to be cutoff) helps A LOT with slowing the process of stripping screws out. Screws usually get stripped when my teammates and I try to tighten them tight with a bad hex wrench. So make sure the end of the hex wrenches are not worn out.

You can always invest in some of the WIHA tools like the Exos:

Hope this helps.

As for my questions for vex,

Is it possible for VEX to have an “upgrade” material for fasteners?
And maybe add a “super” coating on the end of future hex wrenches so they never wear out?


I would recommend going to McMaster-Carr, its an industrial supply company. You can buy most of your screws and nuts significantly cheaper there then what VEX sells.

Here are some parts numbers you should consider looking at
Set screw type 316 steel- 92313A189
Set screw 18-8 Stainless steel - 92311A189
Set screw black alloy steel - 91375A189
Self Locking set screw - 90251A189

There are plenty of more options, just takes a bit to get used to scrolling through.

Also High Torque Hex L-Key
5/64" - 71285A151
3/32" - 71285A152

Check the stuff out, and like I said, there is a lot more stuff out there, and its more often then not less expensive and better quality.

Thanks for the feedback. I wanted to let you know – we’re listening.

We’ve heard complaints about the shaft collar set screws stripping out before. To help with this we’ve taken 2 actions:

  1. We have worked with our suppliers to increase the strength of this screw, eventually we’re hoping this will eliminate “stripping” complaints. It takes time to roll this sort of change out to the entire product line, but I assure you it is in-progress.

  2. We now sell packs of replacement (higher strength) set screws. http://www.vexrobotics.com/products/accessories/structure/276-2385.html

In regards to your request for a “locking” collar set-screw, we haven’t looked into that before. Did you know that the collar set-screws are 8-32 screws, and as such you can use any VEX 8-32 screw in the collar? I know this wouldn’t work in every situation, but maybe you could use one of the VEX locking screws to achieve the functionality you want? [http://www.vexrobotics.com/products/accessories/structure/locking-screws.html


This is good feedback – we currently have no plans for this sort of thing, but I will look into (maybe) rolling out a pack of spares in the future. I’ll also see if we can work with our supplier to increase the strength of these case screws.