> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On
Behalf
> Of Walter Banks
> Sent: 11 February 2011 18:39
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Cutting holes in thick uPVC pipe caps
>=20
>=20
>=20
> Carl Denk wrote:
>=20
> > And on Walter's suggestion of Forstener bits, will have to try that,
> > wouldn't have expected that to work. :)
> >
> >
>=20
> The trick with any cutting of plastic is to keep the bit cool. There
have
> been
> suggestions to pre freeze. I have done that works but a better way is
to
> use
> coolant to keep the plastic below its melting point as it being cut.
> Plastic is
> an insulator and doesn't conduct heat very well so the bit needs to be
> cooled.
> Alcohol is a good coolant because of its low boiling point. Water will
> work
> quite well but needs more care. It the plastic starts to stick to the
bit
> it isn't
> cool enough.
>=20
> For plastic caps that I have drilled I have usually used a mill or
drill
> press
> at relatively low speed.

I've even managed to use the "spade" bits designed for boring holes into
wood with great success on soft plastics like PVC.

Mike

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
law. If you are not the intended recipient of this message, you must
not make any use of this information, or copy or show it to any
person. Please contact us immediately to tell us that you have
received this e-mail, and return the original to us. Any use,
forwarding, printing or copying of this message is strictly prohibited.
No part of this message can be considered a request for goods or
services.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.