On 5/25/2011 10:55 AM, Carla Fong wrote:
Hi all -

I'm suffering sticker shock in getting some material for a project.

I need bar stock, either aluminum or plastic in 3/4" thickness by 3"
wide. Perusing the McMaster catalog I'm finding Delrin at about $20 per
foot, Polyethylene at about $5 per foot, Polypropylene at about $4.50 a
foot, PVC at about $11 per foot and 6061 aluminum at about $20 per foot.

Yikes!

I've prototyped the project on delrin - and it would work for what I
have in mind, but is any of the cheaper materials equally good for
machinability?

The 'poly' group (PVC, PE, etc) looks like a nice cheap option, but will
it gum up when I mill deep, narrow slots through the material? (I'm
taking 0.1" pecks in the delrin and getting OK finish)

Any better pricing on similar material, preferably closer to Portland,
Oregon?

Thanks in advance,

Carla

Science is like sex: sometimes something useful comes out, but that's
not why we're doing it. -- Richard Feynman

You should look for local sources first. With any mail-order place, you
are paying extra for cutting, and then paying even more for shipping.

Aldo if you like Delrin (acetal) then you'll end up paying for Delrin,
because there's nothing else like it. No other plastic machines as well
as it does. ...All the other stuff I've ever seen is not dimensionally
accurate or straight, plus is slippery (hard to clamp), soft, gummy
and/or stringy.