# Traction for 3d printed wheels? DIY traction tires?



## nychris (Dec 11, 2016)

I've been enjoying the whimsical possibilities of 3d printed G-scale parts, for example, after printing out the mine tip car that's on thingiverse, I discovered that I had a whole bunch of 3mm shaft gearboxes from tumbling differential-drive trash-grade RC cars, so rigged one along with 3xAA's to the printed chassis to power an axle and make a "runaway" car.

That can _eventually_ reach a speed that sends it flying off the track, but the key word is "eventually" - with a hard PLA plastic wheel and a little weight on the wheels, there's not much traction so it slips until it gets up to the motor's speed. Obviously things would be better with throttle control for sane acceleration - if this goes anywhere as a project, it is towards something more staid, like a handcar or a streetcar, or possibly a dual-purpose RC pickup / maintenance of way vehicle with fold-down rail wheels.

But what apart from adding weight might I do to increase traction? Trying to find something to make a traction tire comes to mind, any suggestions on how to scavenge something suitable? That printed mine car has really tiny 25mm wheels, but I'm curious about things in a more normal 30-32mm range, as well as a bit larger for potential switch engine drivers.

Any success stories? Any brilliant "cut a slice of this standard hose, it fits perfectly" type discoveries?

I did think about trying to print a wheel with both a rail flange and a hub for a lego tire, at least to explore configuration options for a handcar.


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## SD90WLMT (Feb 16, 2010)

Slices of bicycle inner tubes.
Small ready to buy..O-rings.. Various various out there...
Think out side box..!
SD


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## nychris (Dec 11, 2016)

SD90WLMT said:


> Small ready to buy..O-rings..


O-rings - perfect! I have a whole bunch of those that keep escaping the box they are supposed to be in. I suspect the ones actually on hand are too small, but definitely the right idea, and they are of course available in a wide range of sizes.

----

I wonder what would happen if I made a groove and filled it with hot-melt glue?


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## SophieB (Nov 22, 2015)

You could try Bullfrog Snot. My husband uses it on our O scale locos.


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## Garratt (Sep 15, 2012)

Look into thin walled silicone tubing or flat O rings that will stretch and seat as a tire. Tube comes in many sizes with different wall thickness. I think replacement LGB ones are flat O rings.

http://www.vanguardproducts.com/custom-rubber-silicone-o-rings.html

Andrew


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## kormsen (Oct 27, 2009)

i would try, to smear some silicon sealer on one wheel.


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## Garratt (Sep 15, 2012)

A bit tricky to avoid the tire being bumpedy, bumpedy, bump.
You can get reasonably large (15mm or so) thin walled surgical silicone tubing that is only 0.5mm wall thickness.
That may be too thin and wear quickly. It needs to be retained in a shallow trench on the tread. Perhaps about 1mm or so wall thickness would be ideal.

Andrew


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## nychris (Dec 11, 2016)

Thanks for all the ideas! 

- On the flat O-rings, if I can decide on a size, mcmaster carr's price for a box of 50-100 isn't bad, but it would add up quickly if I have to guess on sizes. I'm seeing hints they are often stretched a lot in this usage, I may try printing various wheel sizes for the 3/4" OD ones I found in my parts box to get a sense of the ratio of relaxed to installed.

- A package of replacement tires for the playmobil diesel was only a few bucks, so if I want to try putting ~38mm drivers on anything I can use a pair of those and still have spares for that engine.

- I also found an O-ring like 30mm OD lego tire that goes on their 24mm sheeve. At first I was looking for a larger diameter leg part to act as a flange, but then I realized I could print a wheel with both the groove and the flange, and hopefully a capture for a lego axle. That could potentially permit some lego technic streetcar power trucks, or an experimental platform work out the gearing and lever lengths for a handcar.


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