PCB Isolation Milling

Mostly Printed CNC - MPCNC Your Builds
1

Decided to try something I’ve never done before since I’ve only ever operated manual mills in the past.

I tried a double-sided PCB… I had quasi-success due to a problem with my alignment holes during the design process. I also messed up the math a little bit for the effective diameter of the V-groove engraving tool that I used, so wasn’t getting quite as wide a cut as I meant to.

Anyway, it was 7 operations with one tool change and one manual operation. The only reason I had a manual operation is because I don’t currently have a way to use my tiny drill bits with the DW660, so just did shallow pilot holes with the machine. The DW660 is a disappointingly limited tool in terms the shank sizes it accepts. Has anyone come up with a clever solution for adapting different collets for the 660? I may end up making my own, but it’s a lot of work I’d prefer to not do if someone has already solved the issue.

I’ve added pictures of each operation along with a few of the mounting and flipping. I learned a lot doing this. It was fun.

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2

Well that impresses the heck out of me. Looks like one you get this dialed in a tiny bit more you we be able to easily whip out some dual sided PCb’s. I love it, I have a blank board ready for a project but nothing has come up yet.

In my little pcb test vid I did the same thing and underestimated the vbit size, or maybe the actual angle, I forget now.

Any suggestions for the easiest pcb software for the beginner?

3

Thanks, I was pretty excited for it being a first run. I can’t believe how much time I’ve taken trying to do math for effective diameter, and I’m never 100% certain that I’ve done it right.

Software-wise, I have had the best results with Fritzing for the design portion (very easy, intuitive), and FlatCAM for the toolpath and G-code generation (easy, but not terribly intuitive). Both totally free.

4

Oh, I should probably add that the G-code isn’t usable in RepetierHost as generated by FlatCAM (no spaces between X and Y moves). It is also weak on feeds and speeds.

I ran this on the generated G-code, which seemed to do what I wanted:
sed -i -e 's/([0-9])Y/\1 Y/g' -e 's/Z(-[0-9+]\)/Z\1 F60/g' -e 's/G00 \([X|Y]\)\(-*.*)/G00 \1\2 F8000/g' -e 's/G01 ([X|Y])(.$)/G01 \1\2 F900/g'

In order, the expressions:

  1. add a space between X and Y arguments to any move
  2. add a feedrate to any Z axis move (F60, in this case)
  3. add a feedrate to any G00 move (F8000, in this case, which I learned was a bit much)
  4. add a feedrate to any G01 move (F900, in this case)
5

Looks good once you get the alignment worked out.

For an adapter for drilling, I was looking at something like this:

http://www.toolstoday.com/p-5161-high-precision-steel-router-collet-reducers.aspx?variantids=5550,0?source=googleproducts&gdftrk=gdfV22404_a_7c1444_a_7c6865_a_7cRB_d_116&gclid=Cj0KEQjw0dy4BRCuuL_e5MeqmNABEiQAq8iNI2JhDZ4g5TfSWE9G6PJmAE4-Z7hHn9g2RDle-QpW5iIaAsi88P8HAQ

The link above looks like a mess, if it doesn’t work, google “Router Collet Reducers”. I have not ordered on yet, but I think it will work.

I will need to check out FlatCAM when I have some time. Thanks for posting you results.

Dave

6

Thanks for the pointer to flatcam. That seems great.

7

Dave, I think I’ll order some of those collet reducers. Thanks for the tip!

Now if we could just find a way to hold 5/8" shanks.