The nice thing about CNC, is you can let it run while you do
other stuff. So today, I updated the original program and ran another batch of .NET
Gadgeteer base boards. the quality was much better this time. I had
a little hiccup (maybe some EMF) for two holes in the board but it
recovered by itself after that and completed the rest. Oh, and the
feed rate didn't take until after the first 6 holes or so (so those
first 6 burned).
Because of the small work envelope of my Sherline, I had to do
the board with two passes, with two different programs. The second
program was identical to the first, except that I moved +5mm on Y
after each row instead of -5mm. That enabled me to simply turn the
board around, use the existing holes to position the board, and
then start the second program.
Here are a few photos
And here's a video of the new boards being stack-milled. Note
that the feed rate is MUCH higher this time, so the milling only
took a few hours, with one visit by me halfway through.
I used 4/40 machine screws to peg the boards together so they
wouldn't shift when I flipped it around. I also used those to help
when I trimmed the boards on my table saw.
Once milling was complete, I evened the sides on my table saw
and then sanded the whole thing with an orbital sander.
