Minimally milling fine-pitch circuit board features

A project log for Minamil: a minimal CNC mill. And friends.

Each axis: $̶5̶$8 motor+lead screw, 3x LM6UU, 3x 6mm x 100mm rod, 1/8in hardboard, PC case screws

Paul McClayPaul McClay 10/12/2021 at 03:190 Comments

update: text style edits; comment re tool change/through-holes

Responding to a comment on an earlier log, I wrote:

I haven't written much yet about the blue Wen dremeloid used for most of this project so far to keep it cheap. The main trick [...blah blah...] acceptable runout. I don't think it was ever going to cut the SSOP footprint tho.

Since then, I got some renewed motivation to try again...

...and made it happen. A perfect spindle would be nice, but in the spirit of pushing down the hardware requirement and frustration with the "better" tool, I went back for another round of tweaking away runout. I'm finding more tricks but don't really have that down to a method for a good how-to yet.

The overall process for milling this example went something like:

Tool changes for drilling and milling won't be so carefully precise. Notice in the video below:

Sub-2-minute video for eye-candy: