Originally shared by Shane Gough A new post about the  and milling PCBs.

General CNC CNC Routers
,
1

Originally shared by Shane Gough

A new post about the cnc and milling PCBs. This one covers the steps needed to set up a level work area for milling and how to use probing and auto-levelling to correct for small differences in height.
http://thegaragelab.com/cnc-probing/

2

@Shane_Gough Hmm, i guess some things in your flow are wrong. Ok here some advices.

  • you use the wrong material for the wodden bed, please use MDF (Medium-density fibreboard) and mill a pocket for PCB. The result have to be perfect. Please remember, you dive with your bit only 0.1mm (or less) deep. Every pice of wood under the PCB disturb you.

  • use a double side tape, to glue ur PCB on the bed. thats let the PCB perfect lying on the bed, without ball and pressure and so on :slight_smile:

  • Please use the autolevel Feature in GRBL or TinyG with chillipeppr, that makes your result perfect.

3

@Frank_Herrmann Thanks for the tips, I appreciate it.

I am using a single piece of wood under the PCB, I’m just using a fairly thick piece of pine rather than MDF so I can bolt it to the aluminium bed of the CNC.

For autolevelling I’m using bCNC which has a similar function to chillipeppr.

The reason for mounting the PCB with screws rather than double sided tape is twofold - first I didn’t want to introduce any other material between the wood and the PCB that would interfere with the height and secondly the screw mounts make it easier to align the PCB for double sided milling.

Unfortunately this introduced some bowing to the PCB due to the tight fit between the screws and the alignment holes - using the pressure probe has eliminated that though and I’m pretty happy with the results.