Rapid Proofing Material

Message: 18
Date: Sat, 28 Dec 2002 15:16:46 -0000
From: "abbylynx <abbylynx@...>" <abbylynx@...>
Subject: Rapid Proofing Material

Hi,

What do you guys use as a proofing material when you want to test out
quickly whether a part will come out like you want. I'm tempted to
use wax since it's nice and soft, and you could remelt all the chips
when you're done and mold it into the shape of more or less any stock
you wanted. What worries me is that it might simply melt like a
candle and gum up the cutting tool/leadscrews/etc etc.

[If you don't spin the tool too fast, wax works well. I've been using the
hard blue machinist's wax from Freeman supply (www.freemansupply.com) and I
like it a lot. They sell it for about $4.50/lb in bulk. You can save your
chips and remelt them. It shrinks quite a bit, but that helps it release
from rigid metal molds.]


So far I've been using some soft pieces of wood I found around my
house, but it's not been without trouble. The fine particles of dust
got into my leadscrews after a few cuts (Okay, it was my fault for
being impatient and blowing the dust as the mill was cutting because
I wanted to see the part :P) and the mill started making horrible
sounds and losing lots of steps. I had to take the whole thing apart,
clean it with acetone, re-oil and recalibrate it. That said it moves
REALLY smoothly now, the Y-axis purring like a cat. :)

[Wood dust can be a problem if your machine wasn't designed to cope with it.
It's attracted to oils and greases, and forms a paste which clogs things up.
Wood routers often use linear bearings and nuts with wipers to cope with
this.]

So what do you use for rapid proofing?

[Ever try any of the urethane tooling boards, like Renshape and Butterboard?
They're easy to cut, and have a good cut-surface quality with less fuzz than
most woods, as well as generating less dust. Freeman has it too.]

Andrew Werby
www.computersculpture.com