I was thinking about 3d printing some of the smaller Vex parts because turnaround time is so long. I believe .stl files of vex parts are on the internet, so it’s easy to translate them into Gcode. My question is, if I print out a vex part that is identical (except for color), I’m allowed to use it on a competition robot, right?
Don’t take my word on this… But the VEX parts are delrin, and if I’m correct 3d Printing parts is in ABS plastic and would not be an identical part. But thats my outlook on that.
“Identical” is a very high standard. I’ve never seen a 3D printed part that I would consider identical to an equivalent injection molded part. I don’t know how you would convince an inspector that your gear’s properties (strength, mass, meshing friction, etc) are identical.
If you were to win a match because your opponent broke a gear, do you think they would consider your printed gear fair? Could you convince them that it was entirely due to your superior design/driving/luck, or do you think they might always wonder if you won because you printed a stronger gear?
The identical parts rule is there to prevent teams walking away with that kind of doubt. If I were inspecting, I don’t think I would allow a printed gear for that reason.
and the ABS part is inferior durability to original injection molded plastics,
I don’t think the inspectors would allow you to compete with (even accidentily slightly) changed components. if it is legal to make your own same metals that vex sells, let me know!
-maybe make this question an official question?
I believe you can make whatever you want, as long as it comes from or is identical to VEX parts, and has no glue, heat, etc. applied to it (you can’t melt down the aluminum to make your own parts :()
For example, buying hex rods and cutting, drilling, and tapping them so that they are functionally equivalent to the standoffs VEX sells.
Using different materials (3D printing) would probably not be allowed.
Thanks for the replies! I hadn’t thought about the full rule implications. It’d be nice to test custom parts before cutting up precious aluminum.
In section <R7> f. of the official vex rules states:
ABS is a stated plastic. Would a 3d printed part printed in ABS be allowed, or no because it is treated with heat during extrusion?
It would not be allowed.
Wow that thread is from about 5 years ago.
But I’m only using the heat to help shape the plastic. The plastic is actually not melted during use in 3d printing. Just heated enough to be malleable. It’s a technicality, I know, but is it a loophole? If there’s some one reading this who is a judge or can contact a judge, I’d like an official rulinhg on this. I myself do own a 3d printer, and I’m sure more people will in the future. Whatever they rule will set the precedent.
So in your original post you referenced the wrong rule for 3d printing. That rule that you referenced was in the normal VRC manual where there is no 3d printing allowed. If you want the VEXU ruling on it look at VUR2
I don’t know about actually printing or anything, I can confirm for a fact that the files are available from the vex store website to download for free, as I downloaded some of the templates when I tried out using CAD for design models as I can’t draw.
You cannot use 3D printing, your are not allowed to heat treat plastic, VEXU has explicit rules allowing for the use of 3D printing, vex at the high school level does not allow the use of 3D printing. The act of 3D printing plastic changes its characteristics (i.e. a 3D printed part would not preform the same in a stress test, as an injection molded part) it also has different texture and other attributes, and cannot be seen as identical
Also, in VRC you may use a single sheet of plastic no more than .07" thick, and almost anything you 3D print will be thicker than that.
As for the 3D parts, this is a question that I posted regarding this for last year’s game. I think the same concept applies to this year but I suggest you look further into this: