Anyone done it?
Thinking of suspension bushes in particular. Looking for ideas/guidance on actual tooling sizes etc. E.g. say I need bushing that is nominally
0.875" OD and 0.5" ID what sizes would you actually aim for?
Cheers,
Alan
not done pu, but done a bit of room temp vulcanising (RTV) rubber, not much use sorry
I might be missing the point here. I thought the material came in rods that were machined to size on a lathe.
I know that is how a similar material called Devlon is worked.
Think it depends on the Grade and Stiffness of the stuff your making it out of.
Hard PU can be machined.. the stuff thats like more like the hardness of rubber is very hard to machine.
We made some PU engine mounts for Tin-top and there still a little too hard for comfortable road use and they were a nightmare to cut it just tore at
the material on the lathe.
All of the bought bushes ive seen are moulded PU. An ex work colleague set up a business doing PU moulding for assembly systems. Took him quite some time to get the grades correct and calculate shrinkage etc. The hard work was in the moulds, although bush moulds are somewhat simpler. The PU he was using wasnt cheap and came in 5l tubs iirc. It had a special mixing gizmo. I wouldnt know where to start for small jobs. id just buy new ones from Mac#1 if i needed to replace any.
Buy rod and machine.
I think I read somewhere that it should be kept in the fridge before machining.
I've mentioned before, my nephew makes false teeth (dental technician) and they use a mix for them. I'll probably see him this weekend so I'll ask what stuff they use and if it's available in softer grades.
Cheers guys.
Thanks for the info. I've machined them in the past, and it's not much fun to put it mildly....Buying them makes sense except for having to
use existing sizes and buy from the UK...pricing is good, it's just the hassle.
Soooo...I looked at the cost of castable PU and it works out very reasonably per bush..I can make say a 10 or 12 piece mould very easily.
I'll keep you posted and share what I learn.
Alan
Just found
Hope it helps...
http://www.bjbenterprises.com/shored.html
quote:
Originally posted by Alan B
Cheers guys.
Thanks for the info. I've machined them in the past, and it's not much fun to put it mildly....Buying them makes sense except for having to use existing sizes and buy from the UK...pricing is good, it's just the hassle.
Soooo...I looked at the cost of castable PU and it works out very reasonably per bush..I can make say a 10 or 12 piece mould very easily.
I'll keep you posted and share what I learn.
Alan