My machine is working on the same principle as the B9C. There are some little differences:
1. The whole print process is controlled by an Arduino Uno, not by a pc. Only the single slices, stored as BMP images, are saved on a pc and are waiting for its retrieval.
2. I am using another projector, an InFocus 3118HD. At present at „only“ 1366 x 768 pixels. No internal modification of the lens barrel was made, an additional lens (f=300mm) is mounted in front of the projector.
3. The horizontal table is guided by 4 linear ball bearings. Its drive is not a DC motor with gear but a stepping motor with a planetary gear. So no incremental sensor was needed for the servo mode and no photoelectric barrier. The same crank drive principle as for the B9C was used. Advantage: The speed of movement of the table is sinusoidal, means low acceleration for the start phase and then for deceleration.
4. The beam of the projector must be blocked (e.g. during movement of the vat) by a two-winged shutter, rotated by a stepping motor. This is necessary because the projector cannot project in between a "black image".
5. The vertical Z-axis has a ball screw. 3 mm thread pitch.
6. The build table is a 5 mm thick PVC plate. Its edges are rounded to avoid any damage of the PDMS during sliding. The plate is adjustable for a perfect parallel position to the vat's bottom by a spherical joint from a tripod. After the vat was moved to the right side, away from the higher platform, the build table is moved up for 3mm and goes down again when the table is in its exposure position. So another sliding over the PDMS can be avoided. I think the B9 works in the same manner. You call it overlift (?).
7. The zero Z-position is found in this way: The current of the Z-stepper motor is switched off and by means of a button on the second shaft end of the stepper the build table is carefully (!) lift down onto the PDMS.
8. The (first) prints directly stuck to the PVC plate. I am not using a printed base plate in between. The surface of the plate is roughened by sandpaper before, then coated by a thin layer of resin which is cured by UV light from a sunlamp. Exposure times: The first two layers are 75 µm thick and exposed for 50 seconds each. The „normal“ layers are 105 µm thick and exposed for 25 seconds. Of course "normal" 75 µm layers are also possible to print.
The WIZARD 1 is still under development. If you like to see my progress (over months), it was posted here on the DAVID-Laserscanner forums:
And in general for 3D printing:
And now here the white-sprayed statue:
Edit: In the meantime I am using the full HD resolution of the projector, 1920x1080 pixels.