Legality of Turning LS Round Axles out of HS Axles?

In short, I’m thinking about experimenting with using a cnc to “turn” (method of machining) square HS axles into cylindrical LS axles for our drive. In theory it would be much more efficient for the drive axles to be bearing load on a cylindrical axle than a square one. I would also grind in flats for shaft collars. This seems legal for VRC, can someone confirm? What are your thoughts? I would also keep a video of us creating them on my phone to show comp officials that they were legal vex parts, and not bought.


Interesting out of the box thinking. Should be legal to do.

Also a way to go from LS to HS for gear/motors on one end.

Please post pictures and how long it took to make a part. I’m thinking you could do this on a drill press.


this is plenty legal. you can physically modify non-electronic parts by cutting or bending all you want. And cnc-ing or lath-ing parts definitely qualifies as a physical modification.


this is legal. i did it yesterday lol

Please use the terms “Milling,” “Turning,” and CNC Machining (if you want to specifically refer to CNC machining). CNC-ing, would mean computer numerical controlling, which doesn’t really refer to any process. Lathing is actually an very old trade of putting wood lath onto stud walls before plastering…it has nothing to do with turning parts on a lathe, which is simply called “turning.” You’ll impress judges, especially those in the industry, by using proper terminology.

Yes, turning parts from HS axles would be perfectly legal according to the game manual R23. Taking a picture showing the STUDENTS doing the work would be a great way to document the work in the engineering notebook, and show to an inspector if necessary.


One thing, when I attempted to turn a HS shaft I ran into the issue that it’s hard to squarely put a square shaft in a 3-way vice. Other than that I see no flaws with this plan.

Yep, square stock needs either a 4-jaw chuck, or use of a square-stock ( collet (most commercial lathes can use 5C collets, I don’t know about the miniature “educational” lathes.). There is a possibility, although I haven’t tried it, that the HS axle stock would fit a 19/64" collet (, since the VEX square stock uses the “thunderhex” concept, that is, fully round corners. (see the VEX pro pages for more information).


Jesus Christ, that one little piece of mounting hardware is 50 bucks?

Yep, and if you buy it now and use it every day you’ll be able to give it to your grandchildren and they will be able to use it too. :sunglasses: And it will still look brand new.


just wait till you see how much the mounting hardware to hold one of those little pieces of mounting hardware costs lol

it’s an investment but like foster said they last quite a while if you take care of them

(disclaimer- the collet in the pic is 5/16” and for round stock and not what i use for turning hs shafts. u want a 4 jaw chuck or 1/4” square collet for that purpose as was mentioned earlier)


Can you post some pictures of parts turned from his shafts? I would really like to see them.

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Yeah I have a lathe (well, my school has a lathe but I’m the only one there, teachers included, who knows how to use it, so it’s practically mine).

I think we might actually have some of those collets, but I’ll have to check on Tuesday.

not yet, but soon : )

@Ethan5956F - Ping to see how the shafts turned out.

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oh i completely forgot about this tbh. i made a lil step down on this one here so it can spin super smooth in a bearing but idt i did any testing with it lol