Page 1 of 2

Skim 390mm discs

Posted: Sun May 24, 2015 10:37 pm
by el_ringo
Hi All,

Can anyone recommend anywhere between Liverpool and Leeds who can do the large discs?

R

Re: Skim 390mm discs

Posted: Mon May 25, 2015 11:18 am
by SuprSi
Hopefully you'll find somewhere, the lathe the garage used here in Southampton could only just fit my 380's.

Re: Skim 390mm discs

Posted: Mon May 25, 2015 11:24 am
by el_ringo
Yeah, I tried a place locally and that didn't fit. Unfortunately the chap who Grizz knows is away for three weeks.

Re: Skim 390mm discs

Posted: Mon May 25, 2015 12:10 pm
by Shoppinit
Putting floating disks on a lathe is asking for trouble. Surely you'd have to mill these flat?

Re: Skim 390mm discs

Posted: Mon May 25, 2015 12:35 pm
by el_ringo
Yes, that would be more accurate. Open to that too. At this rate a new set if discs will be less ball ache.

Re: Skim 390mm discs

Posted: Mon May 25, 2015 12:45 pm
by Shoppinit
The new disks from TPS are quite cheap, but not as cheap as skimming, obviously. What's your issue? I find that the C6 disks pick up deposits quickly, but that you can get them clean again by bedding in the pads again. Or just doing a couple of big stops.

Re: Skim 390mm discs

Posted: Mon May 25, 2015 1:21 pm
by el_ringo
I upgraded to a used a few months C6 set, but found that it was always causing judder so tried the big stops to sort out the deposits. This didn't cure it so I had it checked and the run out is high.

I've just had new steering rack, PAS pipes, cam blet, water pump, 'stat and 20k service so didn't want to add to that bill too much!

Re: Skim 390mm discs

Posted: Mon May 25, 2015 1:26 pm
by Shoppinit
How did you measure the run-out?

Re: Skim 390mm discs

Posted: Mon May 25, 2015 1:26 pm
by el_ringo
A dial indicator at a local garage.

Re: Skim 390mm discs

Posted: Mon May 25, 2015 1:39 pm
by Shoppinit
You could try this that I've just discovered:

http://www.skimmydiscs.co.uk/why-skim-your-discs/

There are some places near you. Have no idea if it's any good though.

/just found out they use one at my local Porsche dealership.

Re: Skim 390mm discs

Posted: Thu May 28, 2015 2:33 pm
by Jultsu
I've only had good experiences with disk cutting (one side at a time), even with floating bells and up to 405mm. I have access to an old (from the 60's or 70's) lathe that used to belong to a school. Accuracy is within 0.002mm on the outer edge of the finished surface. So far I've worked on RS6 C5 365mm, RS6 C6 390mm, S6 C7 400mm, MTM RS6 C6 upgrade 405mm.

Re: Skim 390mm discs

Posted: Thu May 28, 2015 5:15 pm
by Shoppinit
So, Rrrringo, how'd you make out?

Re: Skim 390mm discs

Posted: Fri May 29, 2015 5:50 pm
by Mr Footlong
Thanks for that link Shopp, I have mildly toasted one of my BG Developments 390mm discs and after replacing half of the front suspension, both front wheel bearings and new pads, all that is left is the disc to explain the low speed brake droning on the right front imo.
Not sure if they can do these floating rotor/bell combos though.

Re: Skim 390mm discs

Posted: Fri May 29, 2015 5:51 pm
by Shoppinit
Hmm.. front right... You sure it's not your own semi-frazzled mumblings you're hearing?

Re: Skim 390mm discs

Posted: Fri May 29, 2015 6:38 pm
by SuprSi
My girodisc discs are floating, and the lathe cut them perfectly :)