Since parts can be cut and bent and holes can be drilled, REC is essentially saying that subtractive manufacturing is allowed at all levels of precision, but teams must start using vex pieces as their stock. This does drastically decrease what can be machined, but it also means that most things are still achievable with hand tools. CNC just allows for higher precision.
Additive manufacturing requires a lot more front end knowledge to create parts, and really empowers stronger, well educated teams to perform at a much higher level. If keeping the playing field level is their goal, then providing tools that are prohibitive to use goes against that goal.
Then put limitations on it. Pick materials that are easy. Pick volumetric limitations that essentially make the 3-D printed parts just better versions of what could be subtractively manufactured. Allow n number of 3-D printed parts, each of volume no greater than a m inch cube.
Therefore I would like to recommend that we can have up to 4 3d printed parts with no dimension greater than 4 inches.
This way it is still an erector set but if people want to print some custom support structures, gear boxes, ratchets, or whatever, they can. However, it won’t be most or even a main part of their robot. Just a supporting element that makes their lives easier.
To go a little further down your rabbit hole, there is one other major difference between the allowed fabrication methods and 3D printing: required design tools.
None of the fabrication methods allowed in VRC require any form of computerized design. A team can lay out VEX metal for cutting and drilling using basic carpentry tools (a square and tape measure). They can even get exotic and use a paper template (hand-drawn or computer printed). The same layout tools work just as well for cutting plastic. They can hold a sheet against the robot, trace around it with a pen, then use tin snips to cut it out.
3D printing effectively requires some form of CAD to be effective. While the skill set necessary to do this has come down dramatically, it is a far cry from ‘trace it and cut it out’.
While it is highly recommended, what percentage of VRC teams use CAD at this point in time? I think it is rather low. Introducing a fabrication method that requires CAD effectively forces these teams to either learn a completely new technology or be unable to compete with that aspect of more advanced teams.
I can understand why it looks like the GDC / VEX / RECF are being luddites. I happen to agree with them that allowing 3D printing would unbalance the game even further towards the more technically proficient teams.
I quite frankly don’t see this as a problem. I consider my free access (by being a student) to Autodesk Inventor my most valuable design asset, by far. Real companies in the engineering industry use CAD/CAM packages like Inventor daily, and it is an incredibly useful skill to learn- especially as a student, where you get free, unlimited access to the $2,190 annual program.
Learning a computer-aided design workflow is an essential skill that all young engineers should strive to master, and allowing 3D printing enables an easy and accessible way to reinforce that skill set.
I understand and respect the GDC/Vex/RECF’s choice to not allow 3D printing in VRC this year, but I believe it is an unfortunate limitation of what could be a great learning opportunity.
I feel like next year, the GDC should allow teams to have 1 3D printed parted smaller than a 1 inch cube. This would allow teams to experiment with printing, while the printing not providing a huge advantage (certainly less of an advantage than a pneumatics kit).
I agree with you that learning CAD is an essential skill of engineers, I vehemently disagree with you that it should be an essential skill to compete in VRC. In fact, this directly contradicts the mission of the REC Foundation:
While CAD may be a required skill in some fields of engineering, there is a steep learning curve before you’re proficient. This becomes yet another barrier of entry for getting new students and teams into the program.
There’s lot of ways CAD can be useful in VRC beyond 3D printing robot parts. It shouldn’t be something you’re have to do in order to compete in VRC, it should be part of the progression path students/teams go down as they grow.
Since this seems to be the straw man argument of choice for many in this thread, let’s take a quick look at the differences between allowing 3D printing and pneumatics (without motor penalty):
Pneumatics…
Are heavily restricted by the rules (number of tanks, number of cylinders, working pressure, size of tanks and cylinders, etc.)
Creates design tradeoffs, regardless of if there’s a motor penalty. Many of the people trying to point out of the supposed irony of allowing pneumatics (without a motor penalty) while now allowing 3D printing joined after the ITZ season. ITZ was the last year of Cortex and therefore the last year pneumatics were widely used. Furthermore, any 6th grader who competed in ITZ would now be going into the 10th grade. This means that likely more than half of the students competing this year have never designed pneumatics into their robot. How many of those making this argument have actually designed a pneumatics system into a VRC robot?
3D printing on the other hand…
Limitations on 3D printing (that aren’t full bans) are not easily enforceable. How do you enforce a rule on which printer or material is used? How do you enforce a volume limit? How do you do this while keeping things reasonable for inspectors and teams alike? Creating rules in VRC is a multi-dimensional balancing act…
Does not provide enough of a robot design trade off. “This part doesn’t exist, so I’m going to just print it” or “Modifying this part is much harder than just printing it” are not adequate tradeoffs for the advantages that can be gained from 3D printing. Compare this to the trade off of “If I use pneumatics, I must fit all of these extra components that are of a non-trivial size in my robot”.
Requires a wider breadth of knowledge that is learned from trial and error or from various forums and how-to articles scattered across the internet. Furthermore, creating knowledge base articles to support 3D printing quickly spirals out of control when you consider the number of different printers, materials, and support software that are available today.
These are not the same thing. Quit trying to compare an apple to an orange.
I think the main reason people are comparing pneumatics to 3D printing is not because they provide the same amount of advantage to a team, they obviously don’t. But they do both provide some level of advantage for a comparable price, and I think the case people are making is that 3D printing today is actually quite cheap, cheaper than many robot parts, such as pneumatics or the v5 control system.
But of course cost and affordability is only a factor in why 3D printing is not allowed, there’s the approachability factor, the skill gap that will probably be widened if 3D printing is introduced (is that a bad thing? I’m not sure, it might be), and probably a lot of other factors so I think it’s understandable why 3D printing isn’t allowed. We here on the forum seem to wildly agree that it should be, but we’re a select group of students, and I think the majority of competitors might not want 3D printing.
(Not that I am advocating for 3D parts any time in the near future, for the same reasons given by many others)
BEST robotics (uses cortex system) already allows this. Here’s the general rules that fit similar to what @AperatureLabs was saying:
1.3.2.4 Team Custom Parts
Two Team Custom Parts (TCP) are allowed.
Each part can be made from any uniform (homogeneous) team supplied material.
Each part must be able to fit, unconstrained, into a 2” x 4” x 4” cuboid.
Each part must be a single continuous piece of material (when in its operational state).
The basic raw stock form of the chosen material must be used for the part. The starting raw
stock must be rectangular or cylindrical material if the final part retains any of the original raw
stock shape. Material starting shape is irrelevant for parts that are in a liquid state in the
forming process or if the final part is completely carved/machined from a solid block of the
material.
No other kit parts may be embedded in a TCP.
No hazardous materials are allowed (rule 1.2 item 2 still applies).
No welding is allowed (rule 1.3.2.3 item 8 still applies).
Melting is allowed (rule 1.3.2.3 item 9 is waived).
Chemical change is allowed (rule 1.3.2.3 item 10 is waived).
You could say the exact same thing about the autonomous period/programming skills and programming. In my region, a lot of teams are not capable of programming well enough to have an autonomous, let alone compete in programming skills. The teams that are able to program that well have an advantage, but (outside of basic drive code) the ability to program is not required to compete.
If 3D printing were legal, it would not be required to use 3D printed parts in order to compete, in the same way that it is not required to use advanced programming/sensors in order to compete. Both of those things are things that allow high level participants to have a progression path of growth within the program.
I (satirically) propose we remove the autonomous period and programming skills. After all
"While programming may be a required skill in some fields of engineering, there is a steep learning curve before you’re proficient. This becomes yet another barrier of entry for getting new students and teams into the program.
There’s lot of ways programming can be useful in VRC beyond the autonomous period. It shouldn’t be something you’re have to do in order to compete in VRC, it should be part of the progression path students/teams go down as they grow. "
As an EP, I’m very sympathetic to the argument that enforcing material rules for 3D printed parts is a nonstarter. And there are definitely some exotic materials that would give better funded teams an unfair advantage, and I definitely don’t want VEX to be pay to win. That’s my major concern with 3D printing, and I’m fine with that being a reason to not have it. But, provided there was a limit on the number/size of 3D printed parts, I am not a fan of the idea that we should prevent an opportunity for students to learn how to design 3D printed parts, a very useful skill, just because it would… allow teams that are more skilled to win?
I find the assertion that such limits are not easily enforceable somewhat confusing, considering that in the past the GDC has written rules that do exactly this, back in Skyrise with VEXU:
As an inspector, it seems to me like it would be pretty easy to pull out a tape measure and make sure the parts are within their respective sizing boxes. The GDC could even implement that all parts have to be within a 3" cube (like they did in Toss Up), making things even easier. if you’re that concerned about the inspection process, it would be pretty easy for a team to be required to bring a duplicate of the part in question to inspection where it can be measured freely.
In my experience, the vast majority of the cost of very expensive printers (which can cost upwards of $2000 as you mentioned) comes from their build volume. If you limit the size of the parts to a sufficiently small box, then the vast majority of the advantage a team gains from using a $2000 printer goes away instantly. If it were limited to 3"^3, then teams with $150 printers can essentially print the same parts that teams with $2000 printers can.
I disagree. CAD programs are more accessible than ever and can generally be picked up in an afternoon by a student. The computer hardware requirements aren’t even difficult to achieve anymore. For example, Onshape can run on pretty much any computer that can run windows (In a performance sense; it is browser based), and has plenty of tutorials to get students up and running.
I also disagree that making such restricted 3d printing legal will “add a barrier of entry”. With rules limiting the size and quantity of parts, 3d printing will hardly be required to be competitively viable. Would it be required to compete at the highest levels? Maybe, but at those levels so are advanced programming concepts, which as a software engineering major I can say have a much higher learning curve than CAD. In fact, I would say that autonomous programming for VRC requires much more time commitment and is a much higher barrier to entry overall than CAD would be.
I’ll bite. I’ve been competing (in VRC, now in VEXU) since before there was a motor cost for pneumatics. Not having pneumatics put my team at a significant disadvantage, and it was simply never going to be in our budget to purchase a kit. Therefore, we rejoiced when the motor trade off was added in NBN. I don’t know yet how this year will play out, but it seems to me like the increased weight and space taken up by a pneumatics system are not on their own enough to balance the extra functionality it gives, especially in the era of vastly more powerful V5 drivebases. To be clear, I’m not making a statement on whether they should be legal or not, but rather that I don’t see how they will be quite as balanced as they were in the era of the motor trade off.
How is this any different from the much more competitively important aspect of VRC, programming? Programming a robot effectively takes a lot of work, and while blocks programming may make it more accessible, to get maximum effectiveness text programming needs to be utilized. VEX has knowledge base articles for very basic programming, but there isn’t really anything there that teaches the more advanced but still essential concepts, such as advanced logic and closed loop control. That information has to be "learned from trial and error or from various forums and how-to articles scattered across the internet. "
Overall I think this boils down to a few things:
I think that 3d printing in a limited state, such as it was in VEXU in Skyrise, would not be as competitively overpowered as you are stating it would be.
The barrier of entry to CAD is very low, and in some aspects can be lower than the barrier of entry for programming.
The barrier of entry into 3D printing is pretty low now, and in such a limited state, a team with a $2000 printer would not have much advantage over a team with a $150 printer.
There are immense benefits to teaching students how to use tools such as CAD. While programming understanding is essential for Software Engineering, CAD understanding is essential for mechanical engineering.
TinkerCAD is a good analogue here - it, like blocks, is designed for children and is very easy to use. Yes, the parts you can make are far more crude than real professional CAD, but that only contributes to this analogy. Custom part creation in CAD does not have a high barrier to entry.
My guess it is an example of a constraint… Propose a reasonable starting point like BEST or VEXU SkyRise that is straight forward to understand, and reduces fear that whole robots will be 3D printing and put an end to all new VRC teams.
You can make all the custom parts you want, use VEX Pro products, and challenge yourself to come up with the most complex programming you are capable of in VEX AI.
I am a team coach and 15 or so years ago I took some college classes in CAD and 3-D modeling, but haven’t touched it since. I picked up 3-d printing this summer and after a day of learning, I started calibrating and designing custom parts for my classroom and personal projects. Some of my robotics team put together, calibrated, and then printed some HS Bearings within a few hours with a $200 printer my school had in a box. While it will take a while to really learn the details of 3-D modeling and printing, it is honestly nothing to go from brand new, to just experienced enough to use to solve small problems on their robot. Also, I prefer just a maximum dimension of 4 or 5 inches, which is even easier for a judge to measure than the VEXU rules or the lexan rules.
As stated above, we already have limits on the amount of lexan, which requires a lot of trust to believe they follow, because NO ONE is taking apart every square inch of a robot, laying it out, and measuring. However, just a simple sizing tool could make sure that 3-d printed parts are within spec.
Additionally, restrictions on how many prints could be used still challenges teams to use them wisely, and encourages creativity without increasing the performance gap significantly. Limiting teams to 4 parts can allow for two pairs of symmetric parts, or even a complex mechanism that uses all 4.
I am firmly in favor of very limited usage of 3-D prints to expand creativity without undermining the foundational principles of the game. I feel that 3-d printing and current [restrictive] pneumatics rules make for a robotics competition that employs engineering practices much more in line with modern robotics/mechatronics in general.
A thought I had regarding limiting number of parts, often a single “part” is printed in multiple prints because, especially on lower-end printers, it’s impossible to print as a single print. If you have one of those fancy dual filament printers so you can print dissolvable support material, you might be able to print things in a single print that somebody on a $200 printer can’t.
A possible workaround would be that you can have multiple prints count as a single “part” provided the assembled size is smaller than whatever size limit you impose, and that none of the sub-parts move relative each other.
Of course, this adds further complexity to the rules/inspection, which is not ideal. I dunno, I don’t have a firm opinion one way or another whether 3D printing should be allowed, purely from the rules that become required to keep the financial playing field as level as possible.
If two parts are glued together to make one, and it is a single solid part that is within spec, then I don’t see why it should count as more than one. Fair point.
