Re: 3D printer fun with powder

An interesting aside on photocopiers and laser printers but lets get
back to 3D printing.

A fellow aeromodeler was kind enough to make a video of the roller
spreading the powder, he even marked the roller with a black mark so I
could see the relative motion of roller and gantry. I've asked about
the clearing scraper but it seems a no-brainer and I feel sure I can
actually hear it in the video.

As I suspected the distance traveled by the gantry was basically the
same as the circumference of the roller multiplied by the number of
revolutions it performed over the distance, in other words the roller
does just enough to ensure that the powder it is pushing does not dig
in and nothing more.

I'll stick a stepper on the roller and assemble the gantry belt drive
and then set to work doing the firmware, it should not be too much of
an issue, I can set one pin to operate at some divider of another
using one of the hardware counters, so the roller will be synced to
the gantry.

I also had a most amusing and exciting idea, I'm wondering about
picking up a little Lexmark photo printer we know the Lexmarks tend to
be dumber so that will make things easier. Nema11 motors are quite
cheap if you know where to go and it could be seriously tiny and still
have a useful build volume. But first I must get this one working!

Thanks for all the ideas everyone and the asides, its all very
interesting and thought provoking.

Graham