Guru
Joined: 20/06/2011
Location: AustraliaPosts: 2979
| Posted: 11:55pm 03 Jun 2024 |
GDay OA47, All,
Most copper clad PCBs are 1oz which has only 0.035mm copper thickness.
I don’t know what CNC you use is but that is about 1/3 of what most cheap CNCs quote for their accuracy.
That aside, I am thinking that the bed may not be entirely flat, I would suggest that you clamp a sacrificial block to the table and mill it flat and secure your PCB to it.
Make sure the other side of the PCB is smooth and free from dust etc.
Then try your cuts. There is a fine line when we are talking copper that is only 35microns thick.
I wonder if you could apply drips of wax to these spots before you apply the coating then by boiling the board you may be able to clear those areas.
BTW
I have just bought a new CNC to play with (old one is a standard 3018) a Genmitsu 3020 Pro Max V2. Which purports to be able to mill aluminium and brass. Not that I need to do that much but I like its rock solid stability and lack of backlash.
I think the issue might be more that your table is not perfectly flat.
Kind regards,
Mick. (The big one)
.