The Build

BOM Parts

• 2 CD Cake Boxes
• 1 High Speed Stepper Motor
• 1 Stepper Motor Driver Board
• 4 M3 x 8 mm screws
• 24 Volt Regulated 2 Amp Power Supply with 2.1 mm Jack

1. You will need two Cake Boxes which hold 30 CDs.  These cases have the unique property that the cover can be mounted on both the top and bottom of the base (see assembled photo), and the center post easily snaps off.

2. Remove the center posts by snapping them out.

3. Using a template, mark out 4 holes for attaching the High Speed Stepper Motor, and drill using a 3.5 mm bit for the M3x8mm.

4. Using 32 mm (1.25") drill saw, remove the center post of  cake box base.

5. Now using a 54mm (2.125") drill saw, cut hole in one of the covers. This hole will allow dropping the coating solution onto the substrate.

6. Using 3.5mm bit and template create holes for mounting Stepper Motor Driver Board in the other cake box cover. Making sure to drill the holes to the side and not centered, to create enough clearance between the motor and board.

7. Attach motor to base using M3x8 mm screws.

8. Temporally place control board in base cover, and mark out where holes are to be drilled for the power and USB cords using a 16 - 20 mm (5/8" or 3/4") spade bit. You can also drill a few extra holes for cooling.

9. Attach the 4 motor wires to control board now before mounting the board to the base.  Trying to do this after the control board has been attached to the base would be more difficult.

10. Attach board to base with screws and nut. The screws provided with board are too long and will need to be cut with heavy duty wire cutters, or M3x12 screws can be used.

11. Attach Rubber Bumpers to base now, then place motor base on base.

12. The chuck is now ready to be attached. This is the only component for which I could not find a stock item since the 5 mm hole for motor shaft needs to be precision machined, otherwise there will be significant vibrations at high speeds.

13. The spin coater should now be fully assembled. Next comes setting up the Raspberry Pi and installing the control software.