Re: Vacuum Forming --- Was--->Lights and lenses, the poor mans laser?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:

>
> Graham,
>
> I have been wanting to try some vacuum forming for a while now. Can
> you give me a quick rundown on the process? I am planning to make a
> molded cover for the back of my machine (the one on the home page).
>

I'm not much of an expert, I'm only making really tiny parts. Like
any other forming technique it comes down to the mould. It needs to
have a nice finish if you expect a nice finish (though thick plastics
will still have a nice finish on the other side). You need to add
releif angles so you can get the part off etc. Lots of stuff on the
net about this.

The plastics are normally styrene, abs and even polycarbonate though
the latter will tend to bubble unless you bake the moisture out of it.

For heat the lamp did work really well, before that I put the plastic
in a frame and stuck it in a little oven but I much prefer this. The
plastic goes through various phases, it buckles, tightens and then
droops, you form on the droop. Positive and negative moulds are
possible, negative is better for deep stuff, they sometimes even suck
and blow.

A shop vac is what I use.

Graham