3" Flex Wheel Polycarbonate adapter

Hey all! So one of the many complaints of the 3" Flex wheels is the fact that when put onto the VersaHubs, almost all of the flex is gone. So I have created an adapter that would ideally hold the wheel on firm, but still allow for a decent amount of flex.
Screenshot 2021-03-08 133610
It is designed to use 2 lockbars, one on top and one on the bottom, that would screw in to the holes as shown. I used metal lockbars for this, but you can also use the plastic ones.

Screenshot 2021-03-08 133640
Screenshot 2021-03-08 140224
The holes for the lockbar also match up with the holes on a gear or sprocket, as shown with a 12 tooth sprocket below. This can allow you to connect a sprocket or gear directly to the adapter.

Screenshot 2021-03-08 135633 Screenshot 2021-03-08 135652
I would recommend using standoffs to hold the wheel onto the adapter- the assembly (without the wheel) is shown below:

Screenshot 2021-03-08 134507
The standoffs would go into the holes on the wheels, with a screw and a steel washer to hold them in.
This was all designed in Fusion 360.
Note: For these images, I used a generic white plastic so that it would show up better. You would probably want to cut them out of lexan.

Thoughts, suggestions, and (constructive) criticisms are welcome! And stay tuned! A 3D-Printable one for VEXU may be on the way!

I have not created one of these, and do not really intend to, but I would love to see if anyone does, and tell me how it works out!

(I am not sure how to import a .step file into this as of right now, if someone would like to help me with that, that would be appreciated)
Edit: .step file below.


You could get a high strength hole using Robosource HS Locabars in place of the VEX low strength lockbar. https://www.robosource.net/38-high-strength-lock-bars-1x1-angle


Yeah, I may make an alternate version using those soon, I actually have those in my Fusion 360 Cad library. I didn’t do it with this one, though, because I really don’t see much need for a HS shaft for this. Thanks though!


Cool! I’d love to see the technical drawing for it.

You’d probably just want to zip a folder and attach that.


3_adapter.zip (9.8 KB)
There we go. Thanks, @trontech569.


Screenshot 2021-03-08 150610

I’m still pretty new to this, so I’m not entirely sure how to do this, but here is my attempt.


I would call out the vertical dimensions of the part (you only dimension it in the horizontal dimension). Otherwise, looks good!

cool part, we use something like this on our robot currently. One question, did you ever consider making it in a more triangular shape to improve strength and/or increasing the amount of plastic around the outer screw holes?

I considered that, but I decided against that. I figured that the standoffs going through the wheel should strengthen it. I didn’t want to put too much around the outside of the screws, as I figured that it would decrease the flex. A triangular one would be easier to cut out by hand, though.

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By the way, this also works with a 4" wheel, too.
Screenshot 2021-03-09 140353


looks amazing but before we had gotten our adapters in we had used a 12 tooth gear with tank tread around it and put it in the center whole and there was no way that it was going to come out


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