For a couple of years ago I bought Powerflex polyurethane bushes and
replaced the rubber bushes in the front suspension. I was never really satisfied with the small bush in the lower rear a-arm as it felt like they're a tiny bit too small. Also, the design of the bushes does not do a very good job of handling lateral forces. It has always been on my agenda to replace them with something different and now as the play is worse I've decided to take care of it.
There are many ways to make bushes, and I decided to try to mould my own. Partly because I don't have access to a lathe, but mostly because I'd like to see if it would work out.
So I 3D-printed moulds and reused the steel tube from the old rubber bushes. I used some wax as a release agent, and moulded with a 2-compound polyurethane. I let it cure for 24-hours in room temperature, and then 14h in the oven @ 80°C.
The result was surprisingly good and I put it in the car and test drove it. No play and no binding! I don't know how it would hold on track though, but it would probably be fine.
The design of the bush is still not very good because it still doesn't handle lateral forces.
But I have a new plan...