Roll your own — double disc

Nozzle correction factor is necessary to compensate for your 3d printer's nozzle diameter. Without it, you will likely wind up with a disc that doesn't fit in your machine.

Since the printing nozzle has a diameter, it prints out filament that's a little wide. This "fat" filament affects all parts of the printed disc. In particular, the main center hole can wind up too small to fit in the sewing machine. For example, if the nozzle diameter is 0.4mm, then the center hole will likely have a diameter 0.4mm too small. The correction factor compensates for this. Enter e.g. 0.4 for a 0.4mm nozzle.

To test: the center hole of the printed disc should be 16.1 mm in diameter. If different, set `nozzle` to the difference, e.g. if the printed disc has a center hole 15.7 mm in diameter, set `nozzle` to 0.4

Note: if you generate an OpenSCAD file, you can edit the nozzle diameter in the file. If you generate an STL file, you will need to come back here to make changes. If you order a printed disc, I will handle the nozzle diameter myself.

Standard Elna discs have a certain amount of overhang which can be a challenge for 3d printers. The options to deal with this are as follows:

• Ignore — ignore the problem, hope the printer can handle it.
• Remove — remove the overhang, removing the problem completely
• 75° — 75° slope
• 60° — 60° slope

Note: If you order a printed disc, I will handle the overhang myself.