Author Topic: nylon bushes  (Read 5029 times)

Offline Diamond Hell

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Re: nylon bushes
« Reply #10 on: 29 October 2012, 10:44 »
Ahem.

Syncro.

No beam.

Trailing arms, on subframe.

Big expense is the bushes on the subframe.

Like this:



Big fat fookers.

I seem to recall that freezing poly material makes it easier to cut down to fit, doesn't it?
Just because you're offended doesn't make you right.

Holiday cottages on the Isle of Wight for 2-10 people? PM me.

VW BUSH

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Re: nylon bushes
« Reply #11 on: 29 October 2012, 21:10 »
Deffo poly in that application with that range of movement.

PU generally has a glass transition lower than your freezer will go so you wont crack it :grin:
It will get stiffer the colder it goes, but to be honest your best not putting too much heat into it while cutting as freezing really only works on small diameters and harder pu.
Freezing it to doof it in works a treat though.
There is a knack to machining soft polys, you need to get a cut on (don't be shy), and need to support to stop the deflection if its hanging out the chuck or vice
Use a tool with a fine honed cutting edge (no rough grinding), 2 ish mm tip radius with all the faces cut back to clear the poly rod and a narrow tip angle.
High surface speed and a light feed is a general starting point but hardness of the Poly will dictate this.
The poly should come away in a clean long ribbon and try to drag your face into the chuck :grin:
Milling is best as the material comes away in smaller chips/strips but if you dont have turntables etc then anything round becomes a ball ache...
If it comes off all scabby and stringy leaving a badgers arse behind you are doing something wrong :grin:

If you could lay your hands on a set of powerflex bushes to measure them up, you would be in a good position to try harder PU materials and cost it up properly.

Let us know how you go  :smiley:

Offline Diamond Hell

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Re: nylon bushes
« Reply #12 on: 29 October 2012, 23:21 »
Deffo poly in that application with that range of movement.

Those are just the sub-frame mounting bushes.  They are pretty much static and have nothing moving in that application - those are different bushes, which are much like the small bush on the front control arms.
Just because you're offended doesn't make you right.

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Offline danny_p

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Re: nylon bushes
« Reply #13 on: 30 October 2012, 00:16 »
not afraid of getting a cut on.....   if anything i usally get to ambitious ( mainly due to getting bored stood there watching it )

for the subframe to body bushes i've thought about solid lumps of ali once or twice but something with some give will be better i think,   lump of the hardest poly i can find is the order of the day i think,  due to the nylon / water issues mentioned. 
all the VW's have gone bar 1.

VW BUSH

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Re: nylon bushes
« Reply #14 on: 30 October 2012, 20:59 »
Deffo poly in that application with that range of movement.

Those are just the sub-frame mounting bushes.  They are pretty much static and have nothing moving in that application - those are different bushes, which are much like the small bush on the front control arms.

You will have to forgive my lack Syncro running gear knowledge, I am a virgin in this area :grin:
I would still stand by a "rubber" bush if that's what the car was designed with.
Solid will pass a lot of vibration and stress into the surrounding components and fixings and maybe cause a failure under load
Obviously you can get round the Increases in stress, In pretty much the same way you go about using bearings but this blows dannys seat fund out the back of his pants :grin: