Guru
Joined: 12/08/2011
Location: AustraliaPosts: 322
| Posted: 05:11am 04 Jan 2024 |
Hi All
After persevering with the routing of PCB's for a few days now, have abandoned it.
Learned some lessons that others treading this path may wish to heed.
1. Cutting tools are the biggest problem. The tapered 30 degree or 20 degree type
work great for about half of the pcb, after which the edge goes off the cutter and it starts
tearing the copper. You also have to go to deep to get say a 0.8mm isolation.
If you go very slowly you may succeed, but I wasn't going to wait for 2 hours for a simple board.
Tried a 0.8mm Titanium (coated ??) end mill and still had to go very slow, because it bends.
Being an end mill and going in say 0.075 depth, you are using side cutting which causes tearing of the copper.
2. Table levelling.
With more sophisticated programs you can accommodate an out of level table. I can't.
Even a slight bubble in the very thin double sided tape causes problems, but that can be overcome. To get the table level, I would have to bolt on a block of wood and mill it level
with a fly cutter, then put the pcb on top of it.
3. Board design
A lot of time has to be spent on guaranteeing the gap for the cutter you intend to use.
An isolation gap of 0.8mm ends up being 1.0mm (Bearing play, cutter bending etc)
I also ended up simplifying the design knowing I had to cut it.
Didn't want to drill any holes (except for terminals) so made it mostly surface mount.
4. Finished board.
Hand Soldering components onto a board with a 0.8mm isolation gap is fraught with problems.
Solder will bridge the gap and you spend more time cleaning it up.
Never tried any drilling, but with a drill file converter to gcode that shouldn't be a problem.
However in the end the mass of copper and the grooves all over the board made it look like Sh*t.
Some of you may think (or say) "could have told you so" , but I now understand the router
a lot better and also Kicad 7.
So redesigned the board with all the features that I wanted on a double sided board and ordered it on-line (5 boards for $27) but the killer is the freight. Hervey Bay is a remote area apparently.