Re: 3D printer fun with powder

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Graham Stabler"
<grezmos@...> wrote:

>
>
> Have been experimenting further, the plaster I have is not fine

enough

> I am fairly sure, its certainly not as fine as the corn flour I

have

> so I have gone back to using corn flour even though I have read it

is

> a bit harder to spread than plaster. I'm pushing it through a

sieve

> with a spatula and it seems pretty fine.
>
> At the moment the 10mm roller cuts through the supply area nicely
> leaving a nice finish but the powder it pushes gets turned in to
> perfect little sausages and these roll over the build area without
> dropping in. Increasing rotation speed of the roller helps a bit

but

> powder then tends to get pulled around with the roller and thrown
> backwards.
>
> So I'm going to a bigger roller, I think 7/8" was mentioned before
> anyway, I've picked up some 20mm aluminium tube that I'll polish

up, I

> can always go to stainless later. I have a feeling the angle the
> roller makes with the surface will help and it will be more

difficult

> for powder to find its way over the back of the roller.
>
> Graham
>

Graham, I've the zcorp user's manual, and there is drawing of the
gantry on it, it shows a spreder roller, a snow plow at the sides of
it and what looks like a blade to scrape the powder back to the
front of the roller.this way the powder won't roll on the roller
itself.
It's not very clear, looks like a hand made drawing.
there is also a suction cup on the printer head bay.
I'll try a 20mm anodized aluminum tube and the blade, but first I
have to build a plataform for the printer and the feeding bin
mechanism, so the spreader roller will be last one.