Sankets Journal

How to generate dxf file for top and bottom acrylic case

Author: Sanket Sonavane

Publish Date: 2023-01-29

Last Updated: 2023-03-15

Table Of Content

online tools

apps used

What I wanted to do

So I wanted to generate an acrylic top and bottom plate for a split mechanical keyboard. Normally a lot the popular open source split keyboards have there gerbers and kicad files uploaded to the github repo and those files help you print your pcb. but I wanted to create a acryclic case and for that you need to give your acryclic laser cutter service provider a dxf file. So how do I generate this dxf file from provided kicad pro.

Approach

when you open the kicad.pro file in kicad for the top plate they both seem to have Edge.Cut (border) and F.Mask (plate holes) Layer so you use kicad to plot these files to individual dxf files and now once you have these individual dxfs you need to merge both these to make a single dxf file. This merging can be done in FreeCad.

this is how we use plot in KiCad
kicad-plot

So now that you have two dxf files , open one dxf in freecad and import another dxf in that same opened dxf file. now information of both dxf is present in a sigle document. now you select all layers and export this dxf in FreeCAD and thats how you now have a single dxf file.

using the ruler tool in freecad to measure distances freecad-ruler-tool

repeat the same for bottom plate and give these files to your laser acrylic service and you have your top and bottom plate with plate holes.

EDIT: Seems like F.Mask might generate larger holes than needed so I ended up manually creating those holes (circles) the size of M2 screws on the Edge.Cut layer for top and bottom plate, roughly 2.2mm in diameter. Will get this acrylic cut done and see if all this worked out. will update here.

UPDATE: It worked, the manually generated 2.2mm holes worked perfectly. also ensure the key switch squares are 14x14mm and you should be fine. freecad has a measurement tool which helps you measure the distance between two ends so you can measure the diameter of the holes and distance between opposite edges or a square.

Further notes

While this merging of multiple dxf into a single dxf should be part of KiCAD but its still not there in it, I am a beginner with KiCAD and atleast I could not find this so thankfully FreeCAD was there to rescue.

References