2021-22 is the season for 3D printing!

Continuing the discussion from A community discussion about 3D printing, 2 years after the previous community discussion

@Connor put together a list of why we should be doing 3D printing last May. Here it is a year later and it’s time again to push for 3D printing to be allowed in VRC.

The VEXU seasons have been very successful with 3D printing. A number of VRC have submitted great design winning awards of 3D printed objects. 3D printers are in most high schools and the cost of printers have dropped to the cost of a decent sensor.

The VEXU rules would work, but I’d like to see an addition that before a part is used in a competition that the CAD is available on a public site that if others want to use it it’s available.

@DanMantz @Grant_Cox


I think there are huge knowledge gaps and this would definitely help decrease the margins. This is also a great opportunity to introduce additive manufacturing to the high school knowledge sphere. I don’t think it makes sense to give everyone access to a team’s CAD files, but perhaps the documentation could be publicly availible.

I think there should be some kind of limitations just like there is with polycarbonate and other plastics. Maybe even a weight limit where you have to show documentation of the CAD files and theoretical mass of all 3D printed parts. Possibly even restrict different types of filament to keep as many variables constant.

Price is increasingly becoming less of an issue. Everyone knows of this solid entry level printer that costs less than a v5 brain.


Overall I think this is a really good idea. 3D printing is a really nice way to introduce CAD to newer students and would also raise the ceiling for vex.

I’m not sure how I feel about forcing CAD files to be released, as an inspector I can see this being a nightmare, but at the same time it would help teams that are just starting to learn.

I think a better limit would be (cubic) volume instead of mass. Printer cost generally goes up steeply once you need to print larger parts, so limiting the size of each part to fit in say a 6"^3 box would go a long way towards making sure those with cheaper (smaller) printers aren’t at too much of a disadvantage. In the same vein (limiting costs), keeping the filaments limited to a basic set, say PLA, PETG, ABS, would probably be a good idea, but again I’m not really sure how easy it would be to enforce this.


I wholeheartedly agree this would be an excellent requirement. Perhaps some restriction on the types of filaments allowed.


I am not sure how many teams will bite.
Not saying it is a bad rule, but at the same time this is almost like asking teams to make their codes publicly available before tournaments.

But maybe REC will need to “incentivise” this rule? eg. Tying Inspire Award to the team’s contribution in terms of sharing, etc?

In previous years, I used to disagree that 3D-printing to be included for HS and MS VRC (due to cost and accessibility of equipment), but like what many of you have stated, the cost of good entry-level 3D-printers has gone down. So there is no good reason to not allow 3D-printing for HS VRC.

And I agree - using the VEXU rules will be a good start.


At this point, my concern would be more how would you even begin to enforce it without it being a total headache? Are we really going to stop a team from competing because they forgot to upload a part? How do you verify they’re the ones who uploaded that part? If you wanted to tie an award to uploading your stuff, full steam ahead, but trying to enforce that kind of requirement seems like it would be a huge hassle that’s just going to grind inspection to a crawl slower than security lines at airports.


I agree with you regarding this.
That’s why I am trying to see it from the point of view of “incentivise” it, rather than making it into a hard and fuss rule.


Good questions!

Pretty simple, the same way that I check to see if the plastic is legal. I ask the question on the Inspection form, they answer and they sign the form. It’s the honor system. Unless it’s blatant that those parts came from a bigger than 12x24 sheet I take their word for it. Likewise I’m not running a chemical analysis on the sheet to see it is the correct stuff.

Yep. You want to 3D print you follow that rule. Just like you follow the other thousands of VRC rules.

On the inspection form I’m going to ask where it’s published. I’d be proactive and tell teams “Print out where your parts have been uploaded and bring that paper to inspection,”

@meng and @sazrocks brought up filaments. I don’t really care, I don’t have the means to test, but I can add it to the question on the inspection form. TBH if a team wants to print the entire robot except for motors and electronics, have at it. I’m going to give them fair warning that I’m going to tell the crowd about it and make sure they get the recognition they deserve.

I’ve added this ONE questions to the inspection form:

x) Does your robot have 3D printed Part (Legal filaments are PLA, PETG, ABS circle all that apply)? If so provide the piece of paper that has where they are uploaded.

Should add about 5 seconds to the questions. On my standard 32 team event it adds about 3 minutes to the inspection process for all the robots If the upload info is not available, they flunk, they get out of line and start copying URLS. If they put it on https://www.thingiverse.com/ they just need the 5-8 digit number it was assigned. Not hard to do. Not a huge time issue. Not a big inspection issue.

My goal is to get teams to 3D print. It’s been a huge issue with RECF around the lack of parity for the last decade. So I’m adding parity. If a team doesn’t want to give up their secrets to build, don’t 3D print. But it gives teams with minimal CAD skills to get some help. Remember the mission is to inspire roboteers to get STEM jobs. Trophy’s, banners, etc are just a happy side effect. I’ve seen dozens of teams help dozens of other teams across a season with parts, design and build improvements, code, strategy, etc. This is just another aspect of that.

Hope this helped!

(edited to add the filament discussion)


This sounds like it would work great, and make enforcing the rule seemless.

Is it out of the realm of possibility to, either the day before, or morning of, have teams fill out a google form with links to everything so that there wouldn’t have to be a worry of remembering to bring a paper, because it was all taken care of already? Or is that then reaching the territory of making it a hassle?

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They can do whatever they want. Google sheet. Excel sheet. Photocopy the page out of their bound engineering notebook. Limitless on what they do, just hand it to the inspector.


Key point - permanent evidence as evidence during inspection process.


I really don’t think that teams should have to share THEIR parts for EVERYONE ELSE to use. If I do the work for it then i should be in charge of who gets to see my work. That would be like forcing me to share my code or my engineering notebook.


i said the same thing 2 years ago, but vrc really ought to have 3D printing by now. financially it’s nowhere near as prohibitive as it used to be, and even costs less than many vex parts as others pointed out

as for enforcement and general rules, i agree with the cubic volume idea, since it seems a lot easier to eyeball for inspections than weight (given that the part will be attached to the actual robot)

i completely agree with this approach as well


The thing is, your part most likely won’t work for other teams unless they have the same robot as yours. Think about a custom 3d printed change up intake- they could copy all of the wheels or rollers on it, and it may work, but they would probably need to change the part to be able to mount it to the robot, unless they have the exact same robot as you.
And in the end, what’s wrong with sharing your code or notebook with another team? I could see a problem if you came up with a super new creative way to make auton more consistent and don’t want to share it yet, but they’re going to see your robot and program run during the matches anyway.

I would love to see 3d printing on robots, at least in some limited capacity- I think that the 3 parts that can fit into a 3x3x3 Inch cube as discussed in the other thread is the way to go. Another thing that may be good is giving teams a choice between using lexan and 3d printed materials, since that would give teams that don’t have access to 3d printed parts another way to make custom parts, and could even the playing field a little bit.
I would definitely like seeing a database with 3d printed parts from teams- maybe on the teams robotevents page or somewhere similar? That way the inspectors could have the robotevents page for the team open at inspection, and check off that the are shared. If they aren’t shared, they don’t get to use the parts.
Vex could also make an online challenge out of it, where teams would document their parts and do a write up about them, similar to the make it real challenge.


Long overdue!!! 3D printing - really the part design leading up to the print is a critical skill to be learned and there is no reason to not be part of VRC lets go, lets do it!

If you don’t want to share, you don’t have to 3D print. Buy you will be clever and embed “67101C” in the plastic. Teams that just grab and print will have your logo / team number on their robot. That is some serious homage. Remember that you also live on in their engineering design notebook entry: “We took this 12 double reverse bar with each bar sized by the Fibonacci sequence that allows it to expand from 15 inches to 32 inches with just one motor and held together by shoulder screws. The design efforts by 9MotorGang of team 67101C are amazing” Judges do ask where ideas come from and at least my judges frown on taking ideas and not giving credit.

There are five groups to appease here:

  1. RECF - they want something that helps improve the program, but something that won’t put teams too far behind teams that have “unlimited finances” or there is a lack of availability. Once craft stores, big box stores, etc. started selling poly-carbonate plastics, the rule came into being.
    By having an existing rule in place (VEXU is unlimited 3D printing) and seasons of seeing it in action this requires one addtional line in the inspection process and a cut/paste from VEXU rules to VRC. But it’s a huge game changer for teams.

  2. Event partners - we want nothing that will make us add people or extend the time of an event. My proposal that could add up to 3 minutes to the inspection process is danger territory. The additional 1 min training course for volunteers on what a 3D part would look like and how to collect the URL sheet may be a deal breaker. But I’m confident that if we keep it simple that people like @lacsap will be able to help in this.

  1. The VEX Worldwide Coaches Association on Facebook - this is a group that is totally against any extra work or cost by the Coaches unless it benefits the roboteers. So this proposal is on the edge with the work, but it’s well under the additional cost and work that they were happy to ignore for VEXIQ field and element upgrades. So it should be a thumbs up from them.
  1. Roboteers - they have been asking for this for a very long time, I thing that a huge majority will jump on this in a heart beat. A few teams may decide that the publish requirement is too much to give up and that’s actually a great thing. It teaches engineering tradeoffs that companies make all the time.
    But I’m also looking for some advanced engineering, currently putting screwed bushings into 3D parts helps in attachments. I’m looking for teams to stop a print, drop in a metal axle reinforcement and continue the print.

  2. VEX Robotics - this is revenue neutral to them, people are not going to 3D print parts that are available from them because the costs to buy heavy duty injected molded plastic are less than trying to print the equivalent. Team 3D printing also gives them examples of things they could decide to re-engineer and issue out as standard parts. I still think there is a demand for the next size up in sprockets.

Lets’s do 3D printing this year, I’ll work on notebooks and code sharing next season :upside_down_face:


Uhh, no atleast for local competitions.
I would be fine sharing code and notebook at states and worlds if needed but if I have to share at local competitions I might just not bring my notebook at all.


Interesting; you’d choose to give up eligibility on winning Design/Excellence in order to keep your code and EN under wraps?

I understand the fear behind not sharing code. However, I think it’s unfounded - teams are too focused on getting their own stuff to work. Team code shared at season’s end by James’ thread indicates most team’s code is tailored for a very specific robot.

I’m a big fan of open-source and even moreso in educational settings. I think opening up all (EN, Code, 3D designs, CAD) resources that students create will lead to a stronger community.


I like this. It’s one thing to have something publicly available, but teams could just call it widget 3.3 and no one would be able to find it even if an inspector could verify it. Robotevents could then allow you to see a team’s submissions, and they could also build in a way for an EP to print out all of the submitted parts for a given team at an event. For true sharing, you would need to have easy links set up like below.

This link could give you all of the submitted parts for team 12345A:

I would be fine with putting my teams’ notebooks on that page as well.

This link could give you a list of all the teams at event RE-VIQC-21-4554 and their parts:

Inspectors wouldn’t even need to print off the parts list, they could just view it from the RE page as it’s a list of just the teams at a particular event (or division within an event if applicable).

Why not? Do you really think it would put you at a disadvantage? License plate holders would be one thing as they would be pretty universal, but a lot of custom parts would only be good for your particular application.

When I was speaking with our local VEXU team a couple of years ago, they commented that they just do a lot of printing because it looks cool, and almost everything they do could be done with standard parts. I don’t think there is much of an argument at all about competitiveness. It just a matter of the time and effort you put into your project, as with all of the other aspects of your bot.


3D printers are now getting cheaper and easier to use, and I have to agree that 3D printing in VRC would be awesome.

Poll time!!

3D printing in VRC
  • I have access to a 3D printer and I would love to use it in VRC!
  • I don’t have access to a 3D printer, but I would like to get one to use in VRC
  • I do have a 3D printer, but I don’t want to use it in VRC
  • I don’t have one, and I’m not going to get one for competing in VRC
  • I would love for 3D printing in VRC to become a thing, and I would order prints online
  • I am like Grayson Meme Lord and I have mixed feelings

0 voters

edit: added poll

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