Alan B
|
| posted on 13/12/06 at 07:32 PM |
|
|
Casting Polyurethane
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
|
|
|
|
|
liam.mccaffrey
|
| posted on 13/12/06 at 08:11 PM |
|
|
not done pu, but done a bit of room temp vulcanising (RTV) rubber, not much use sorry
Build Blog
Build Photo Album
|
|
|
JonBowden
|
| posted on 13/12/06 at 10:13 PM |
|
|
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.
Jon
|
|
|
MkIndy7
|
| posted on 14/12/06 at 12:14 AM |
|
|
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.
|
|
|
DarrenW
|
| posted on 14/12/06 at 09:07 AM |
|
|
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.
|
|
|
designer
|
| posted on 14/12/06 at 09:25 AM |
|
|
Buy rod and machine.
I think I read somewhere that it should be kept in the fridge before machining.
|
|
|
Peteff
|
| posted on 14/12/06 at 12:23 PM |
|
|
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.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
|
|
|
Alan B
|
| posted on 14/12/06 at 01:36 PM |
|
|
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
|
|
|
Angel Acevedo
|
| posted on 9/10/07 at 12:49 AM |
|
|
Just found
Hope it helps...
http://www.bjbenterprises.com/shored.html
Beware of what you wish.. for it may come true....
|
|
|
Angel Acevedo
|
| posted on 14/1/08 at 05:56 AM |
|
|
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
Alan,
Any progress??
I live in Mexico, and I haven`t been able to find PU Bushings on the sizes I need.
Thanks.
Beware of what you wish.. for it may come true....
|
|
|
