Dumb idea of the day: Remelting old wheels to…
Or am I just really fucking stupid, I mean science says they melt around 300*C depending on the composition
Who wants to do science for the greater good? (I would but I don’t have extra wheels)
Really?
Wheels are not produced by freezing of a liquid, they are produced through a chemical reaction. You can’t “melt” them and reshape them because polyurethane is a thermosetting polymer. Heating it will just cause it to ignite and burn.
Damn…can you bond new PU to an old wheel if you have the right polymers/additives/catalysts/conditions?
There is Thermal Polymer Urethane (TPU) used in 3d printing but I don’t think the urethane used in skateboard wheels has the same ability to be melted and reformed like @b264 said typically plastics and synthetic rubbers are made through chemical processes and recreating the same mix and end product is tough to impossible. From what I’ve seen most people use super glue I think for patching small cracks in wheels to prevent chunking but if it gets too bad the cost benefit analysis says just buy new wheels.
SmoothOn is a company I’ve bought some resins from (expensive… probably over-priced but they do a good job informing you on how to use their products via videos which I appreciate). They sell resins that mix into various hardness plastics, but only some of them are safe for home use others require industrial setup with exhaust vents etc. to keep things safe.
This is a sad day for me…if I can remelt wheels then I was thinking of how to make a tank short board…toss a couple load cells in the deck and use them to run separate ESCs with an Arduino or something for differential steering. Anyone happen to know how to make a wheel from scratch?
What quantity? The process for 4 is much different than the process for 4000 
You can print wheels with TPU that work well enough at least for RC vehicles (like RC cars, not sure how long they last though) and imagine they would even work with a person on board but again longevity of the part is what I would question here. If you’re just tinkering around then this is a fine way to go just wouldn’t trust 3d printed wheels if going at any sort of above walk off of it speed.
^^ this guy has done a lot of different projects using TPU, some shoes some shirts, and wheels in the video there. You can get TPU with different shore hardness but I’ve never actually compared the ones available to skateboard wheels to see if they’re anywhere in the same universe (also can make them more forgiving by decreasing infill, but can’t make them more rigid than the TPU itself).
For something more permanent I used my 3d prints to make molds then pour resin in the molds, but it’s a pretty long process: Custom Pulleys
Volume wise maybe the same as like 2 or 3 sets of 90mm wheels? I was thinking encasing metal tread plates with a 8mm layer of textured PU for the tank build and maybe the perforated pattern for airless tires to make 140mm street AT wheels with tread pattern
Having worked with the TPUs that are available for most 3d printing, my opinion is they are strong, but not wear-resistant at all. I believe the TPUs available also are much softer than is customary for any skate wheels. If I was crazy enough to print wheels that I’d trust, I’d recommend one of the Nylon blends. – those can wear quite a while as long as your print head can get hot enough to get good self-adhesion. the Nylon filaments I’ve used (various taulman blends) are a little soft, but probably would work, with a hard inner core
What would it take to cast wheels with thermoset polyurethane?
Now, lets get serious @ZachTetra … anyone in the forum ever tried to transform lead in to gold? Seems like a nice good idea, what you think?
I’ve printed some nylon pulleys so have a bit of experience with that too and agree in terms of durability and strength can’t really be beat (… within 3d printable plastics… maybe polycarbonate but I haven’t tried that myself yet). Only down side for wheels with nylon would be the natural “self lubrication”, also the spring in a wheel helps it absorb energy and nylon could be too rigid (maybe not just a potential other issue). Either way agree I don’t see it as a really long term or durable solution but fine for some tinkering and keeping the experiments cheap, just don’t bank your life on it.
I’ve played with PC it’s such a pain to print well I’m pretty confident without post-processing annealing (and the risks of deformation!) that the first rock you hit with a PC wheel while the >75KG of rider and board would turn to shrapnel. un-annealed PC fails… quite impressively.
As for the hardness of nylon, I’m pretty confident the slickness would only be a concern for very smooth surfaces – like polished concrete.
The springiness of taulman is about 60 on the D scale, whereas skate wheels range from 70- 100 on the A scale.
IIRC that will put printed nylon on the side of speed skate wheels – so designing some tread in the print would be a good idea, if trusting your body to 3d printed wheels was a good idea at all!
Personally – Having tried using a 3d printed wheel while refereeing for roller derby… nope! i ended up borrowing the wife’s spare set of wheels.
Right didn’t mean PC would make great wheels either and heard it’s worse than printing with nylon but might make more durable parts depending on the kinds of stresses/strains involved (was out of context though)
Same guy made esk8 tires. I’m not sure how the held up over time though.
