Summary

This is a complete redesign of the bracket model from the original project.

https://www.breadbox64.com/blog/diy-mechboard64/

The DXF in the project has errors, and it was pretty much unusable, so I used the PCB to get exact measurements and went from there. Every key has been painstakingly placed where it is supposed to go according to the drill file in the Gerbers. The PCB fits with 0.5mm of clearance on the top and bottom.

The two halves must be assembled using glue. The gap between the two parts is 0.2mm which is quite small and the fit is very tight (you may have to scrape the plastic with a blade to get a perfect fit because of inevitable deformations on the printer bed). For PLA I use cyanoacrylate adhesive or two-part epoxy.

There is another project that cuts the brackets in three parts. I found that if you don't use a brim or a skirt, you have just enough space on an Ender 3 to split the keyboard in two parts. Also, the way the three part keyboard was cut was a little naive, some switches had to sit between two parts, creating a lateral pressure that had the effect of separating the parts. I kept switch holes whole, and each switch sits entirely on one half or the other. That has the added advantage that it gives a continuous surface with more area for the glue to hold the parts together.

Print Settings

Printer Brand:

Creality

Printer:

Ender 3 Pro

Rafts:

Doesn't Matter

Resolution:

0.2 or 0.28

Infill:

10%

Notes:

I had good success with 0.28 layer height and adaptive layers.

With these settings, you can get a pretty fast print with a good fidelity at 0.6mm line width (even with a 0.4mm nozzle) as long as you select wall ordering from Outside to Inside in Cura.