3d printed quick swap motor thing

For those of you who don’t know, to make a motor quick swap is to use zipties to hold motors to their fronts instead of the screws that they are typically held shut with, making motors easier to replace if they die or you need to swap the cartridges. Since this doesn’t affect actual matches, and just makes life easier for builders, would it fall under wire management, as one of my teammates suggested, or nonfunctional decoration? If the latter, would it be legal to 3d print something to hold the motors together so that we don’t have to use and cut so many valuable 11 inch zip ties?

If I was doing inspection, I would consider that functional cause it’s keeping the motor together/connected. I would call it illegal though I think that would be nice to have.


Very good idea! But sadly I also agree that these 3d printed parts are very much a functional part of the robot, and would not be allowed.


well, yeah, they do have a function, but it serves no role inside of the match, its more of a thing to make life easier for builders and to reduce the waste of zipties. Of course, I’m not going to use it unless we get official approval, but I’d like to be able to.

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Another option is releasable zip ties. (Though, I haven’t tried these myself, so I’m not sure how effective they are.)

If you think the 3d-printed solution might qualify as cable management, then you should ask on the official Q&A.


I don’t see how releasable zip ties would be considered legal either. Just because VEX sells a certain type of zip tie, does not mean that all types of zip ties are considered legal. The official wording of using parts that aren’t directly from VEX is that the parts used on the robot must be “identical” to the ones sold on the VEX website. Granted, there is of course some slack to this rule given to zip ties. Pretty much any regular zip tie that is of the same length/width of an official VEX one will do, however there is a major difference between the zip ties VEX sells and the mentioned releasable ones.

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Fair enough, I guess this is up to specific rule interpretation as well. Probably worth a Q&A post.

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What Q&A would be right for that? Nether judging Q&A nor Online Challenges Q&A seem right.

The official game Q&A.


VEX sells battery straps, which are fancy resealable zip ties:


But, in my experience, I wouldn’t really trust the battery straps to hold up to potential motor strain, especially after a couple of uses.

Now a good question would be how to build a similarly functioning piece out of Vex parts. (But the way I see it, this solution would be big and bulky, and not very practical to use.)


How secure is the attachment, do you have a picture of how it works? Is it secure does it shake around?

The attachment doesn’t exist yet, I didnt want to spend time cadding and printing something only for it to be declared illegal.

IMHO, this is clearly not wire management or non-functional decoration and, if I were inspecting, I would deem it illegal and not pass your robot unless an official Q&A were to be posted that allowed it.

You aren’t managing wires, you are affecting build. Even if you were managing wires, it would be illegal unless commercially available (see that discussion topic). It is clearly functional, as it changes how you can build. A non-functional decoration isn’t allowed to affect build (for instance, a big 3d team name decoration must be backed up by legal material if it blocks cubes from getting stuck somewhere). How the robot is built and what materials are allowed is the core of Vex; just as well say we should be allowed to use any metal or any plastic parts (not just Vex) - sure, might not change much and might make things easier… but still illegal (at least at this time).


Maybe there might be a way to quick fasten motors with vex pieces.
Are we talking about fastening the two halves of the motor together, or fastening the motor to the robot?

Connecting the 2 halves of the motor

Well then, is quick swap with zip ties legal? It says zip ties are legal for wire management, and they are assumed legal for nonfunctional decoration. If quick swap falls under the latter, which makes sense, as its not adding or removing or changing any functionality of the motors, than the argument could be made that a 3d printed part is legal. If not, than the argument coulde be made that quick swap isn’t legal, though I’ve never seen anyone be given trouble for using it.

All official ruling concerning for this seasons’s game must be made as responses by the GDC to the Official Q&A on robotevents.com- this is explicitly explained in the Game Manual for Tower Takeover.

Using (official Vex) zip ties in general is perfectly legal; you are not required just to use them for wire management. We’ve used them in place of screws, to hold things at weird angles, to move balls down specific paths, to help on rubber band intakes for flipping caps, etc. In the game manual it even references zip ties as an example of a restraint one might use for maintaining a starting size.

That said, a debate I recall from years back was in fact that quick swapping itself may be illegal (since it could technically be considered a modification of an electrical component). @Karthik did address this at the time, though, and state that it was in fact legal (as teams could use motors that were missing motor screws, and removing those screws was an allowed process for changing internal gearing).

This doesn’t have any real bearing on your 3d printing question, however, because zip ties in and of themselves are legal for regular build use and 3d printed items are not.

As @lacsap stated, if you want something official you have to go to the GDC official Q&A. Everything on the forum is our best guess & opinions only!


I had specifically asked earlier on this season Official Q&A about previous seasons Q&A carried over - and the answer was essentially ‘no’ - and that response was added to the game manual.

So, if you want to do ANYTHING that is not explicitly spelled out in the Game Manual, you MUST ask again for the current season’s Q&A for it to be competition legal.

So it may seem simplistic for me to say to ask the Official Q&A for official answers about the current season’s exception, event though they have been answered for prior games, that is the official rule.

Functional and non-functional for 3d parts is pretty clear - if you can remove the 3d part from the robot and have it keep doing what it does, then it is non-functional. If it stops working, then it is a functional part. In this case, specialized 3d motor casings would appear to be functional… if you removed them, then the motor parts fall out…

Please ask the Official Q&A on such issues.

It is a good discussion…