Re: 3D printer fun with powder

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:

>
> In Graham's machine, he is trying to use the roller to level the
> dust. I can see a lot of ways this could go awry. I wonder if
> a blade would work better, but the commercial units seem to use
> the roller. But, there may be a non-obvious trick, like static
> electricity, roller surface characteristics, etc.
>
> Jon
>

Essentially the roller acts as a blade but a blade that constantly
lifts the powder preventing dig in.

You could imagine it as a paddle steamer paddle with an infinite
number of paddles, no powder can exist above the lowest point of the
paddle (that's the leveling effect) but the paddles will flick powder
forwards onto the powder ahead of the paddle. There is very little
friction between the new and old powder because it is never dragged
rather it is lifted and thrown forwards, it is this friction that will
ruin the old layers because they become dragged up.

I don't think there are any special tricks because on occasions I have
got half decent results by hand.

Graham