"Spencer" wrote in message
om...
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Hi Harold,
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Maybe the outside surface is just a cut surface, but with great care
taken with tooling, angles, lubricant, etc. I don't cut delrin with
any kind of fluid, I just go slow.

Spencer

Hey Spencer,

Just a little tip on cutting Delrin. The faster you run it, the better it
performs. If you keep your tool nice and sharp, the finish is superb.
Delrin does not get gummy from heat like many other plastics. I've had
chips coming off in a continuous ribbon that shot over my shoulder and piled
up on the floor in a nice heap. It is one of the nicest of all the
plastics to machine, the only problem with it is it has considerable stress
and moves about a great deal as you rough it. Be certain to rough parts
before finishing, leaving a reasonable amount so you can remove the error
generated by the movement. I've often done it in three phases to get
parts straight. I used to make telescopic blowpipes for bagpipes, which is
where I learned of the tremendous movement it displays.

Regards,

Harold