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Carl Ijames[_8_] Carl Ijames[_8_] is offline
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Default Plastic roll pin

"Tom Gardner" wrote in message
...

On 7/12/2014 9:02 AM, Bob Engelhardt wrote:
On 7/12/2014 5:29 AM, Karl Townsend wrote:
...
My *guess* is pre sltting would not be any easier and would slow down
the CNC lathe work.


The trade off is slitting 15 4" pieces vs 1 5' piece.

BTW - I found a source for 1" x 3/4" Delrin that prices it at $37 per 5'
piece. $2.50 material cost for each 4" piece! 'Course when you're
buying 2500', you'll get a better price, I hope.

Bob



Their lab tried that size and it's too small.
[/quote]

So when you say they will supply the Delrin, does that mean they supply
tubing with the correct id and od, or what? If the outside is going to need
turning to size, use the 1" tubing, do the cut/deburr/slot ops then slide
each piece onto a SS tube mandrel (have to experiment a bit on the size) and
toss piles of them into an oven at 425F or so for 30-45 minutes. The Delrin
will anneal and relax and take up the new ID of the mandrel +/- a bit, so
you get your correct od without turning the full length. Two sets of
mandrels so while one batch is baking the other is cooled, finished tubes
removed, new ones loaded on the mandrels and the mandrels loaded into a
crate maybe standing them on pegs or whatever, so the entire oven can be
unloaded and reloaded quickly. Anyway, just a suggestion.

-----
Regards,
Carl Ijames