Teflon glide bearings

[Bob PerkinsParticipant @bobperkins67044]

[Bob PerkinsParticipant @bobperkins67044]

My current requires a Teflon glide bearing. I have Delrin rod in the odds box but no Teflon. From the info I've read on delrin it seems more machineable than Teflon but I'm unsure of its "glide" characteristics. Is it a suitable alternative?

[Anonymous]

Delrin machines beautifully; Teflon is a bit of pig to machine as it can deform rather than cut, and creeps like there's no tomorrow, making it difficult to hold tolerances.

In terms of friction coefficient, Teflon is about an order of magnitude lower than Delrin, but whether Delrin is suitable for your application will depend on the other surface, the forces invoived, lubrication or not and the effect of static friction.

Regards,

Andrew

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Bob & Andrew,

What Andrew writes is true of pure PTFE (aka 'Teflon'  ) but I seem to remember mention of a material which is PTFE with some sort of a filler.

It still has almost as low a coefficient of friction as PTFE but the filler gives it (more) dimensional stability.

I don't have a name for it and it might be difficult to procure in hobbyist quantities but other forum members may be able to throw more light on the subject.

Best regards,

Swarf, Mostly!

 

Edited By Swarf, Mostly! on 06/03/2013 22:26:26

[BazyleParticipant @bazyle]

We needed to machine a bit of teflon 2ft long going from a couple of inches down to a point. Impossible until they froze it in liquid nitrogen.

There are different grades of Delrin/acetal but might be difficult to find specials in hobbyist quantities.

[KWILParticipant @kwil]

Try Bay Plastics for PTFE loaded bronze

[Michael GilliganParticipant @michaelgilligan61133]

Bob

Have a look at ebay seller:benchrisseb

He stocks a good range of PTFE and similar materials

… no connection except as a very satisfied customer …

MichaelG.

[Chris HeapyParticipant @chrisheapy71135]

Agree with MichaelG about the Ebay seller, I have cleaned him out of my favourite filled PTFE (60% bronze-filled) but it difficult get the size(s) that you are looking for. To buy this stuff new from a stock supplier is prohibitively expensive so buying offcuts is a good solution. My need was for 2 different sizes – 30mm O.D. tube and 8-10mm rod. I managed to get some 30mm O.D. rod but of course machining that down to provide some thin 30mm O.D. seals was a criminal waste of material. But I had no choice

For the small diameter rod I cut up and turned a heavy walled section of 5" tubing, the square-ish sections thus produced provided me with nearly 2-1/2 metres of 90mm-long rods at 10.5-12.5mm diameter. Perfect, and a lot cheaper than buying that as new stock.

Edited By Chris Heapy on 23/04/2013 16:48:09

Edited By Chris Heapy on 23/04/2013 16:48:52

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