Larger OD Washers for High Strength shafts

This is a request for a new product. Sometimes the kids run their high strength shafts through a hole they create in C-channel, etc. Often, they will use the black high strength spacers to try to position those shafts. The problem is that those high strength spacers have a square hole and are not much bigger in diameter than the shafts themselves, so if the kids make too large of a hole through their C-channel, the black spacers too often get jammed into that metal hole and cause lots of friction and/or just get mangled.

I suggest a “high strength” plastic washer that has a round hole (instead of square) and a larger outside diameter, so they can’t get jammed into holes in the metal supports. It would be great if the kids don’t have to make their own such washers, since that process can be not only tedious but also a little dangerous because their fingers need to get so close to a sanding belt, etc.

Such washers are already commercially available, so Vex wouldn’t need to do much other than just stock these or allow these types of washers to be used in the rules.

Just drill the holes to the right size and the current spacers work well. Asking for huge washers seems pretty absurd when all you have to do is drill holes to the right size.

Edit: 400th Post!

Well I would like to see some bearings for them, iv’e never seen any.

There are bearings available here.

Thanks, I guess I just never saw them.

We have drilled the nylon washers for these too.

Using a drill press works better when drilling the nylon washers. Clamping down the washer is key. if you are going to do it often, make a jig.

What sort of clamp are you using? From what little I know, clamping from the side (radially) tends to distort them.


What our club uses for spacers on high strength shafts is high strength shaft bearings, but with the holes that you use for attaching it cut off

Hold it from the top. There is not a ton of room though so it is time consuming.

If we need a bunch of these I was going to make a jig to hold a small stack of them in a tube or in a square and drill through it. They may travel up the drill bit but that may be OK.

With the presently available black high strength spacers, there is also the problem of the square hole. When kids are trying to build gear boxes, etc. and are trying to tweezer some of those square-holed spacers into a tight-fitting gear box, they have the additional frustration of getting the square hole to align with the square shaft. If they had washers that would slip onto the shafts without requiring such an alignment, things might go a little faster when working space is limited.

I’m not even sure why square hole spacers are superior to regular washers, but I’m confident somebody will soon explain it to me.

+1 to this. Very hard to put them on in a tight spot. The last one on being a drilled out 1/8" white spacer can help a lot with this.

The tight fitting square makes the spacer not move so you have some benefits that way.

I’m just curious in what kind of situation is that an advantage?

I think when you want to reduce friction as much as possible, then a round-holed washer would let anything slip that wants to slip, but a square hole means there are fewer things slipping since the square-holed washer must follow the shaft.

Also, wouldn’t round-holed washers simply be less expensive?

In a spinning situation like a wheel or a lift arm, the majority of slop movement on the shaft is stopped by the square spacers. Does not move much but you have a wee bit more than a 1/8" left of slop and that is where the last cut out one comes in with your tweezers and the round spacer cut out. Now it is adequately secured and not moving left to right.

Like you said above, if you use the square ones only, you have to hold that last square hole spacer just right as you shove the high strength shaft through the other parts and perfectly align the final spacer blindly. Frustration ensues.

I agree, I hate the square inside shape. I don’t understand why they aren’t just circular like all the spacers for the smaller shafts. Every time we have used the high strength shaft spacers we have gotten angry with that darn square hole.

The current high strength spacers basically serve the double function of a shaft collar.

If you screw up drilling the metal just cut a piece of polycarbonate and drill a hole.

I don’t think they really do though. You can’t trust the spacer to fully hold a gear from sliding around, therefore you need shaft collars also.

Have you used only spacers in lieu of collars when the need to hold a gear or wheel in place arises?

I didn’t choose my words carefully as I was in a hurry, so allow me to reiterate:

In my experience, the high strength spacers over all fit much more snugly compared to the regular spacers on standard shafts, and won’t slip off too easily.

So the closest commonly available drill size that would allow a large shaft to pass through is a 5/16 inch drill bit. That’s 0.3125 inch. I measured the OD of the black square-holed spacers at 0.39 inch. That’s a diameter difference of 0.0775 inch, which works out to about 0.039 inch difference on each side of the shaft, or about the thickness of my thumbnail.

Considering that the kids often de-bur these holes using a file by hand, it’s not unusual that their resulting hole sizes will be larger than the square-holed spacers, which might explain how these type of spacers are getting jammed into the holes and becoming mangled, etc. I don’t see any advantage to these square-holed spacers over plain, flat, round-holed washers that have a somewhat larger OD.