Anyone who has delved into DIY wheels knows that they are a trickier than it may seem, especially if the wheels aren’t just for show and need to provide things like decent traction and durability. 3D printers have helped a lot, but they’re not a cure-all.
Check out how [Robert K.] makes wheels from segments of automotive silicone hose, which are constructed with fibers embedded within them for durability and structure. Not only are these hoses easily sourced, but the silicone makes a great wheel surface and the hoses themselves are highly durable. He uses a 3D printed jig to cut a slice of hose that press-fits perfectly onto a 3D printed hub. [Robert] finds that a 28 mm hose pulled over a 35 mm diameter wheel is a perfect fit.
These wheels are for a Beetleweight class combat robot, which are limited to three pounds (1.36 kg) or less. You can see some video of [Robert]’s previous Beetleweight robot named ‘Bourbon’, and we have featured what goes into the even-smaller Antweight class (one pound or less) in the past.
Please, don’t cut my automotive silicone hose into your DIY wheels
You cant tell us what to do darius!
There used to be a circular section vacuum cleaner belt, maybe for actual Hoovers, that made a nice tire for a smaller wheel, haven’t seen them in a while though. They were good to pick up cheap on clearance. That was back when every department store and hardware store carried vacuum belts though.
Lightly loaded tires, you can also get away with using small bore silicone or rubber tubing circled around the wheel and spliced together. Not good if the weight involved is gonna flatten it, or the motor torque is just gonna strip it off. However for more weight handling, low speed, you can slit it lengthwise and pull it over the sides of a thin enough rim, but then you’ve only got the single wall thickness for cushioning. If you don’t need too much grip on something small you could save stripped off wire insulation for it I guess, that’d be coin sized wheels really.
Polycord can easily be molten and pressed into molds to form small tires.
Wouldn’t rubber provide more traction than silicon?
Rubber is most often a general term for a wide range of very flexible materials, silicon, butyl, polyurethane, etc. There are so many synthetic types of rubber, that when referring to natural type, it’s usually called specifically natural rubber or latex rubber.
In any case, silicon rubber with a durometer in the 50A range is pretty grippy. I have some from a project that needed to be food safe and high temperature, and it would definitive make good wheels/tires. It’s not slick at all.
Silicone!!!! Not silicon.
https://xkcd.com/386/
Just going to leave this here: Silicon O ring comes in diameters and you can stack them sideways if you need wider tires.
That’s what came to my mind, too, but … those are going to be like 20 or 10 cents apiece, whereas this is more like a few bucks per foot, which might yield 20 or 30 “tires”.
Rubber washers would also be pretty cheap if you don’t want to cut. And maybe some garden hoses would work well if you’re willing to cut your tires.
How about bigger diameter softer wheels? I have (1:10 scale) DIY RC-car project waiting for some really good ideas. At the moment I’m thinking I will be forced to go with the boring commercial option and buy some 1:10 RC wheels. I’m trying to do as much as I can myself, so some other options would be nice.
At that scale you might find just straight up 3d printing them in a flexible material the best option.
You can then tune the infill and perimeters to get the desired softness in the tyre.
Next best/ perhaps the best DIY option after that involves creating molds to fill with whatever grade of grippy stuff you want – a 2 part silicone, those silicon that stinks of vinegar as it cures tubes usually used in bathrooms, natural rubber, almost endless options so take your pick. This will allow you to create exactly what you want with a great deal of effort. – So i’d say its only worth it if you can’t find a good match to buy. Make sure to pay attention to things like mold release or your rubber tyre and the mold could end up one solid lump.
Folks, we need to be clear about our nomenclature here. We’re all smart enough to know these things, but I’ve seen this error twice in these comments.
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard and brittle crystalline solid with a blue-grey metallic lustre; and it is a tetravalent metalloid and semiconductor.
Silicone also known as polysiloxanes, are polymers that include any synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms, combined with carbon, hydrogen, and sometimes other elements.
It’s true, ‘silicon’ when one means ‘silicone’ seems to be a particularly stubborn error for some reason.
I’ve been thinking about this and wondering for a while now… my spelling was “perfect” as a child, but after living overseas for a few years, learning the basics of multiple “English-alphabet” languages, and learning to read Cyrillic and Arabic, my American US spelling has gone to shit. Is it because I’ve gotten older? Is it because the parts of the brain responsible for “correct” spelling have been repurposed? Any studies on the topic?
In college, I had a friend on staff who was like 8 years older, and I’d always be reading emails like “OMG, what the heck!” It’s been a steady downward slide since then, I routinely go back and look at what I wrote and see just random freestyling in there, not even like you’re/your type things, sometimes there will be words a significant edit distance from what I intended. I think it’s just that your brain gets full and you get diminishing returns, then your brain starts declining …
An alternative may be to use silicone chaulk, and rotate your (still wet) wheel over a stationary wiper to make it round.
Silicone chaulk is quite sticky and stretchy, but it tears easily. It can be reinforced by winding yarn into the silicone before drying.
You can also use RTV (Room Temperature Vulcanizing) compounds, which are higher quality silicone based glues.
There are also many 2-part silicone rubbers which can be poured into a mould.
Silicone hardens by absorbing moisture from the air, not by drying out, and thick layers of chaulk can take very long to dry.
In the movie / prop / masks industry sometimes a bit of wetted (wettened?) flower / corn starch or similar is mixed through the silicone to make it harden all through.