mrgnex

Some of my ball joint dust covers are deteriorating. There does not seem to be any form of replacement (be it OEM or universal/aftermarket) and the only way to fix it is buying a new suspension arm.
I was thinking I could draw the dust covers in CAD and have them printed in TPU, possibly outlasting the rubber stock solution.
The part I'm worried about is layer adhesion and durability of a TPU print under the car.
What are your thoughts on this?

MincVinyl

For the most part the boots would be within the wheel and mostly protected. IDK universal replacement boots are faily cheap if you just make a list of all the sizes needed then amazon replacement prices. I tend to replace arms as a whole, which assumes the ball joint has already gone bad.

mrgnex

Thank you for your insights! Getting replacement arms here would be a magnitude of what I paid for the car and more than it's worth to me.
I have hard time finding universal boots since the stock ones seem to have wonky sizes.
Luckily my ball joints are in great condition. I cannot see or measure any play.
Maybe I need some more research to find the right universal boots but I might come out defeated. So this was my backup plan.

MincVinyl

I wish I had spent more time on it, but one of my coworkers at my last job had used TPU for linear rail bushings. They came out really well with 5+ years of expected use.

How cheap could it be to print a set? Like $5?

spectre6000

Try it and let us know. Share your models.

Laminar

TPU is a squishy, flexible material kind of like rubber. It wouldn't be used for a bushing.

My last roll of TPU cost $25/kg. The final piece would probably cost pennies in materials.

MincVinyl

Yeah it may not have been TPU then, I know he had a few different rolls he was having fun with on the Prusa. If I remember correctly it was 85A durometer.

Fickert

iTrader: (6)

They make various TPU's and TPE's with durometers. For a boot id use something in the 55-65A range if possible. It prints like a wet noodle so it takes time. It has back pressure effects due to how squishy it is inside of the extruder. Pressure advance is something to take consideration of when using it. a 85-95A TPU would require a pretty thin wall thickness, and it got pinched, I'd expect it to fail pretty quickly.

I would think you could make a thicker 1.5-2mm wall thick boot with that stuff and it would work well.

Again, if it is worth your time, IDK if it would be worth mine. But to experiment and use that for other ideas or projects could make it worth while.

I have some 55A filament at home and it is impressive when you get a print to complete with it. I can't seem to find the brand without being at home but here is some 60A stuff.
https://spool3d.ca/tpu-60a-ultra-fle...nter-filament/

motodenta

Easy to print, need a direct driver printer tho.
However, not reasonable to do. I have a bag full of all boots set with grease and zip ties, bought from facebook group, never get around to use or needing, only grab 'em to have spare,
they look very generic and should be able to be found online.