We, Team 1989 are in the process to test 3d Printing the robot. Currently allready printed a “skateboard” frame about 32x28 in and in process to 3D print 4 planetary gearboxes to drive the 4 wheels (in place of Toughbox Minis or so) If everything goes the way we want we will have a “metal free” robot for the most part (except motors and electronics etc and maybe some steel bars to make up the weight close to the 120 lb if this year is a “shoving match” year) Otherwise its going to be PVC hex shaft reinforced ABS, PETG and Nylon with some nuths and bolts. If you are interested in seeing our progress I will post videos once or twice a week or so as a basic “How to 3d print and FRC style robot” (hopefully if it works) on my newly created youtube channel at
It will include filament reviews, print settings and things as to how to do the math and how to design a compound planetary gear box (currently in the works) or how to do a rack and pinion setup etc. Depending on the shape and challenges of this year we might have 15-20kg of filament on our robot this year.
I will definitely be following you quest! We also have embarked on the design of a Swerve Drive which incorporates a 3D printed caster and a number of accessory parts and covers.
Our biggest concern going into the effort is how well the printed parts will survive to vibration, shock and aggressive driving.
Our caster prototype was printed using carbon fiber reinforced nylon. We are in discussions with our local MarkForged printer distributor to investigate printing those caster parts that will be the most abused with Kevlar reinforced nylon filament.
Depends on what you are after. If you take carbon fiber Niylon for example it is both stronger and weaker than the base material. The carbon fiber particles make it harder but the flip side is as they are just particles and not cloth or threads like in a carbon fiber sheet they do not add to the tensile strength actually all particles decrease tensile strength and adhesion and also “mess” with the hydration level of nylon. So if you are worried that your caster or any other part suffers from abrasion or is too flexible an bendy then the carbon fiber or whatever other particle you have mixed in might help as it increases the hardness. If your prime goal is great layer adhesion and tensile strength then you want a Nylon without any particles in it. For a caster or a wheel I’d probably prefer some give and might make up the stiffness by printing more perimeters and upping the infill and see how that goes. I cant see a properly printed Nylon wheel break under the loads we put them through. We are thining on doing some wheels too and will at a later point experiment with some nylons and even some flex stuff for the tires. As you probably know Any Nylon is pretty slippery and you might want some grip So a wheel with a hard core and then a softer Tire might be the trick. Right now we did some speed tests with the planetary gearbox (Bridge Nylon) and it is holding up very well to be run at full speed of the CIM motor (about 5000 rpm) with no visible wear. So our next step is to print 4 of them and stick them on the frame parts we already have printed and load them up with 120 lb (probably a kid or some lifting weights and drive it around the hall ways.
What A good idea. I watched your first video and subscribed to your channel. I will be very interested to see what you learn and how well this project goes.
I’m unclear what ‘base material’ you are referring to-- as far as I know, Markforged just uses Onyx, which is nylon with chopped carbon fiber. If we aren’t talking Markforged, then there’s a whole lot of materials out there…
On the topic of 3D printed wheels, I believe 2175 did ABS wheels in 2013, so I’d agree with your assessment that Nylon (with or without chopped carbon fiber) are likely to perform acceptably in that role as well.
Base material is for example Nylon in Carbonfiber Nylon or PLA in carbonfiber PLA etc. Anyway its all material and every one is good at something and not as good at another. So when you design it you make an educated guess and the when you print it you find out. One thing that speaks against CF for many applications is the cost as we are limited as to what we can spend in material that is on the robot out there. So even though a lets say $200/kg material would be ideal to make the whole robot out of and if you figure you are going to use 15-20kg to do that you have spent enough on filament that - to stay within the rules you probably use the spools it came on as wheels and power it with 2 rubber bands. As we probably (hopefully) will do the whole robot in 3D and will have the 15-20kg of filament on the robot we atm guess that we need to limit the average price of filament to about $30/kg to leave room for all the other stuff that goes on the robot So that means a lot of low cost ABS and PETG and some Bridge Nylon and reinforced with 1/2 in hex pvc solid rods as you can get those for something in the neighborhood of 1.30 to 1.50 per foot (US Plastics) Depending on how many feet you buy of that stuff. I think last year we were allowed to have like 3k worth of stuff on the robot out there and if you got fancy wheels and Talon SRX and a bunch of sensos etc you get close to that rather quickly and it becomes an issue. Hence I am testing the cheap Hobby King PA (Nylon) to see if its useful to our needs. Just figured out its a 6/6 most likely so you got to rehydrate it after you print it.
