What does it take to make decent tires for your projects? According to this 3D printed tire torture test, it’s actually pretty easy — it’s more a question of how well they work when you’re done.
For the test, [Excessive Overkill] made four different sets of shoes for his RC test vehicle. First up was a plain PLA wheel with a knobby tread, followed by an exact copy printed in ABS which he intended to coat with Flex Seal — yes, that Flex Seal. The idea here was to see how well the spray-on rubber compound would improve the performance of the wheel; ABS was used in the hopes that the Flex Seal solvents would partially dissolve the plastic and form a better bond. The next test subjects were a PLA wheel with a separately printed TPU tire, and a urethane tire molded directly to a PLA rim. That last one required a pretty complicated five-piece mold and some specialized urethane resin, but the results looked fantastic.
Non-destructive tests on the tires included an assessment of static friction by measuring the torque needed to start the tire rolling against a rough surface, plus a dynamic friction test using the same setup but measuring torque against increasing motor speed. [Overkill] threw in a destructive test, too, with the test specimens grinding against a concrete block at a constant speed to see how long the tire lasted. Finally, there was a road test, with a full set of each tire mounted to an RC car and subjected to timed laps along a course with mixed surfaces.
Results were mixed, and we won’t spoil the surprise, but suffice it to say that molding your own tires might not be worth the effort, and that Flex Seal is as disappointing as any other infomercial product. We’ve seen other printed tires before, but hats off to [Excessive Overkill] for diving into the data.
Please, spoil the surprise. No-one wants to watch a video if they don’t have to.
Although we might miss today’s sponsor (probably not Flex Seal).
You won’t believe the result! They don’t know you know.
Is this the future you wanted?
[ Yes ] [ Ask later ]
Urethane casting of the wheels performed the best overall. The directly-printed filament tires (PLA and TPU) were slowest and wore the most on asphalt though appeared the least deformed.
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The high-effort cast polyurethane came out on top, followed by printed TPU, with hard PLA and Flex Seal sprayed over ABS both being pretty poor. The Flex Seal appeared to work really well at first, but the thin layer wore off quickly leaving hard ABS to suck just as much as hard PLA.
Thanks to you both.
Made me wonder if Plasti-Dip, the actual dipped kind, not sprayed, would work. It seems pretty tough in the few applications I’ve used it. Not sure if it’s tire tough, though.
Dip a rotating tire form into the goo (maybe slightly thinned) to evenly coat it, then have it keep slowly rotating until cured.
Or maybe truck bedliner would work. It’s quite tough. Traction could be an issue.
I wonder how hard it would be to print some rubber filament directly on the rim, rotating it around its axis instead of moving the printer table. The “rotary Y” setup is easy for a laser, but seems more complicated for a printer that has to take corrections for diameter increasing every layer…
A lot of the experimental printing projects seem to use Python to post-process the gcode. “All ya gotta do” is scale the Y moves by 2pi(layer_height) for each successive layer.
I think you also have to scale the extrusion.
It seems perfectly doable and reasonably simple from the coding side. If “bed” adhesion doesn’t fail (perhaps metal rims and a heating element on a drill chuck?) it could be used to print some sweet airless tires. I think I’ll sacrifice my old knockoff Prusa-clone…
Maybe a empty casting, as a original wheel, would help with the grip.
it is said that lego is the biggest tire manufacturer on the planet by units delivered. and i have enough of them to fill a good size tote. so i just print adapters. still this kind of science is very useful.
I wonder if you can use dual extrusion to do the tire equivalent of hobnailing to extend the life of 3D printed tires while maintaining their flexibility and grip?
But what TPU was used? Probably some rock hard 95a.
(To be fair, I haven’t watched the video, but) I wonder if you could make a PLA wheel with a “mold” on the outer diameter, just wide enough to pour in two part urethane, then peel away the outside layer of PLA, exposing the thin layer of urethane. I might give this a try if I ever need to make wheels…