Isolation Routing

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msimpson
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Posts: 2816
Joined: Tue Mar 30, 2004 6:19 pm

Isolation Routing

Post by msimpson » Wed Jun 14, 2017 10:46 am

I am starting an in-depth web series on isolation routing printed circuit boards.

I will start by creating a fixture that will help create an easy way to mill a board with as little setup as possible.

I will start with some easy tests to make sure your physical setup is sound, then move into single sided board milling.

Finally, I will jump into dual sided milling.

I will cover the software and process needed to create the board drawings.

You can find my initial postings here:
http://www.kronosrobotics.com/isolation ... troduction

If you have any questions or comments, please feel free to post them here.

baysale976
Posts: 414
Joined: Mon Dec 31, 2012 11:07 am

Re: Isolation Routing

Post by baysale976 » Wed Jun 14, 2017 8:06 pm

I'd love to see a greater discussion of cutting tools, including brand and model/type.

I have a CNC PC Board drilling & milling machine I built in the 1990s that I've used for (some) isolation routing, and for that I made a fixture to hold PCB material. Basically it was a piece of MDF with a pocket milled perfectly flat (by the machine), with small clamps in each corner to hold the material down. I haven't used it in years - not many PC Boards these days - but it did its job well in the day. I never did get a great tool though, settling on a 1/32" mill and going quite slowly.

As for double-sided, each 2s board had two Index holes, pre-drilled, so I could expose, etch and drill the board and have both sides register (line up) well. the alignment holes were part of the PC Board pattern of course.

msimpson
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Re: Isolation Routing

Post by msimpson » Thu Jun 15, 2017 6:50 pm

Did some testing with the 20 degree V-bit today and have to say it exceeded my expectations. While these are not true CAD generated PCBs, they do show how tight the system is.

The spacing on the tiny little rectangle under the CNC text has a spacing of .02" and still leaves enough isolation and clean traces.
_MG_7067.jpg
The little machine I am using (Titan) needs some calibration on the X-axis but other than that its much better than some of my earlier boards I did on the KRMx01 back in 2011. Titan has a water cooled 3HP spindle on it and it purrs like a kitten even at 24000 RPMs.

Here I was able to run a trace cleanly between two pads on an DIP.
_MG_7076.jpg
Here is my writeup on the tests:
http://www.kronosrobotics.com/first-tests-1/

munsonryan
Posts: 34
Joined: Tue Nov 15, 2016 3:39 pm

Re: Isolation Routing

Post by munsonryan » Thu Jun 15, 2017 10:39 pm

Way big double thumbs up. I hadn't even considered circuit boards when building my KRMx02, but this is a huge un-expected bonus... electronics are my second favorite hobby...

msimpson
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Re: Isolation Routing

Post by msimpson » Sun Jun 18, 2017 10:42 pm

Still working on my single sided workflow page.
Here is a quick vid of a circuit I just made.

baysale976
Posts: 414
Joined: Mon Dec 31, 2012 11:07 am

Re: Isolation Routing

Post by baysale976 » Sun Jun 25, 2017 3:37 pm

Very nice Michael.

What software are you using to generate the cutter path?

msimpson
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Re: Isolation Routing

Post by msimpson » Sun Jun 25, 2017 9:41 pm

I'm using Eagle software and the PCB Gcode plugin.
http://www.kronosrobotics.com/setting-up-the-software/

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