Re: lexmark 3d printer is back

> I'm using just plain plaster, it does not spreads nice.
> Zcorp plaster is granulated, almost like refined sugar, it should
> spread very nice, I don't have enough zcorp powder to fill the
> feeding bin with it, so can't tell for shure.
> i've tried refined sugar and it spreads very nice.
> The rotation speed was just to get the powder spread,not shure at
> what speed it's rotating, I guess it's about 200rpm.
> The type of plaster is very important, as it should spread without
> lumps.
> There is a granulated dental plaster that I've to check it out.
> I think that the main thing is to get the right binder or glue to
> hold the plaster particles togheter and does not clog the printer
> head, that's a tough one.
>

I tried corn starch which I baked in the oven for a while to dry it
before passing it through a seive, it definately had the potential to
spread nicely as sometimes it did. Sugar water can be used to set the
starch I think.

My conclusion was that the roller should more or less turn so that
it's surface speed matches the linear speed of the gantry. My
reasoning was that the roller should act more or less like a simple
spreader with the turning acting to prevent the pushed material from
digging in. Spinning two fast tended to send the powder backwards and
on to the smooth surface. It probably does not require syncing but a
consistant motor speed would be good, then you could adjust the gantry
speed to match.

Graham