The Great Re-Invent The Wheel Project

[garthscs]

I have been experimenting with 3D printed wheels of different plastic types. The Great Re-Invent The Wheel Project combines 3D printed plastic wheels with an aluminum axle hub. So, the idea is design any wheel you like in 3D print and vulcan mind meld it with a metal hub with set screw axle mounting. The best of both worlds combine if you will. The aluminum hub is produced by Steve at Ranch Design. If you would like to try the idea the hubs can be purchased by sending Steve (Ranch Design) a PM (personnel message on the 1-43 HRW forum). Photos of the test program to date attached.

[TuscoTodd]

That is a slick idea!

[HO RacePro]

I have been printing 1/32nd scale front wheels and tires in TPU (ThermoPlastic Urethane). I'm printing the wheel and tire as one piece. I press-fit and superglue a 3/32 inch ID brass tube into the center so it spins freely on a 3/32nd inch OD stub axle. These wheels/tires have been successful in IHSR racing.

I true them on my Professor Motor machine, clamped between two shaft collars tightly enough that they are both square versus the axle and locked against it in rotation. They can be sanded concentric to within one-thousandth of an inch.

The downside is they aren't pretty. But I have made round self-adhesive stickers printed with wheel images to give them a little bit of detail.

The TPU filament I use is pretty high durometer, so they are a bit noisy. But that hardness also gives them minimal traction -- desirable for racing. Add to that the fact their OD is tapered, so only the extreme outside edge of the tire is in contact with the track.

I am planning to try fitting them with ball bearings. I also intend to try wet polishing them with an extra-fine wet/dry sandpaper -- 1000 grit or above.

I have to say your printed wheels do look gorgeous. Do you true them? Might be worth trying.

[garthscs]

Most of the plastics are remarkably true. The trick so far is getting the printed hole just the right size before reaming to .125 diameter. Also pressing the hub insert in must be done very accurately. The hub is designed to have a very slight interference fit. I also epoxy glue with the just a small amount. Different plastics can be trued as well. That being said I have had great success with more than one type of plastic. I do all of my on Cad drawing so I have control of the print files I send to people to print for me.

[HO RacePro]

Garthscs,

I used to have others print my parts. Then I saw I could buy a Creality Ender 3 Pro printer for about $250. For what I was paying to have my parts printed I could easily justify buying my own machine. Downside: I had to learn a whole new technology. Upside: I could refine my parts through many design revisions quickly at almost no cost. Filament is cheap!

If you have the smarts to do CAD you can do the printing.

And in the 2+ years since I bought my machine there has been a lot of improvements in the technology. I am about to install a major upgrade to my machine at a cost of US$110. It basically replaces all the hardware except for the X/Y/Z drives. I'm anticipating significant improvements over what was originally a pretty capable machine. If you go shopping for a printer today you should be able to get all that newer technology included.

For accurate press-assembly I use my drill press. The spindle feed gives me exact vertical motion and more than enough force. I can fit an axle in the chuck to help hold a bushing square for insertion.

An extremely useful tool is a dial indicator. You have no good way to know how true your wheels and tires are without one. They're not expensive and dirt simple to use. But you may need to lubricate your tires to prevent drag/sticking versus the indicator.