RE: Re: Stereolithography machine

I think your accessment is correct, that UV lasers are expensive. There
some diode lasers around 400 nm, 20 mW. Even these are in the multiple $k
range, not quite UV, and rather low power.

Maybe a better way to go would be to use DMD's and a UV arc lamp. These are
devices made by TI and used in TV projection. Resolution of most of them is
720P. A UV lamp putting out several watts would be patterned by the DMD and
imaged onto the film of polymer. This could be put together from a TV
projector with a different lamp and mildly tweaked optics. The imaged
region would be focused to about a 0.72" patch for roughly 0.001"
resolution, and step and repeated to cover the whole area.

TV projectors have offset fields, so the actual usable field size can be at
least twice the actual imaged size. Therefore lens motion can be used to
scan, reducing issues of field flatness that some scan schemes would have.

Further image size could be accomplished (much more slowly) by moving the
entire projector parallel to the surface of the polymer being exposed.

Sounds like a fun project.

Elliot Burke

From: "skullworks" <skullworks@...>
Subject: Re: Stereolithography machine

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Mat" <bergson7@...> wrote:
>
> Hello friends
> I am trying build small stereolithography machine and we have
problem
> with Ultra violet laser for it. There are a couple sources for it
but at
> the moment all of them are quite expensive. I am still searching.
>
>
> Is there anybody who made or tried make this in the past ?
> Best regards.
> Mat
>
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