DIY wheel and sleeve casting

[DerSi]

Same here. They only loosened from my diy hub motor one time after I exaggerated it. They literally melted off when motor temperature exceeded 90 degrees celsius without me noticing that
Apart from that, no defects at all but i don’t drive them very often either

[Eratrace]

Give my 2 cents here since I’m regularly working with PU, for PU to bond well to aluminum you need really good surface prep and cleaning (sandblasting and acetone for example) and a primer that will attack the aluminums oxide layer and protect it until casting, I’ve used OP9018 from electrolube with some success but some others might be better for aluminum.

[phamaral]

I’ll actually try to cast on top of a regular urethane wheel, not alluminium. Don’t know how well my cast PU will bond to the wheel’s PU so that’s why I was thinking about drilling holes on the wheel. That way the cast PU has something to flow into and lock in place. I’ll do some experimenting first to see if they are really needed though.

Here’s a cross section of the mold i’m designing. The yellow mesh on the inside is a scan of my 83mm wheels. I’ll tighten it in the mold with a bolt and nuts

Don’t know if any of this will actually work, i’m just having some fun.

[phamaral]

Little update on my wheel extension experiment.

The 3d printed mold worked great. But even though i put a layer of vaseline on it the wheel just wouldn’t come off so i had to destroy the mold. (Since it can’t be reused i’ll redesign the mold so it uses less material and is easier to destroy).

My first try casting the PU looked really good until I got tore apart the mold and the bottom was uncured.

Don’t know what happened here. Maybe on the first mixing batch I got the proportions wrong or mixed poorly but I did exactly the same thing on my second attempt and it came out great!

This 70A PU has a really short working time of 40 seconds. Really hard to work with but it was some of the only PU I could find here in Brazil.

And since I botched the first one and wasted some PU on some tests I don’t think I have enough left for three more wheels, but can cast another one for sure. Then I’ll ride them and see how they feel.