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Slipring episode 2: laser cats

Well no cats, but we did use lasers.  We had read about a different technique to transfer the pattern to the board. You paint the copper board with black spray paint, then use a laser cutter to burn away all of the paint where we don’t want copper.  After that the process is the same as the toner transfer, you soak it in the acid to remove all unwanted copper.  

We made up a test piece from scrap copper.  The laser cutter was able to etch the paint but it took over 5 passes and even then it wasn’t really perfect.  also we were hoping the laser cutter could cut out our center and bolt holes, but for some reason it wasn’t happy with the plastic of the board and wouldn’t cut through it. 

  Video of the laser cutter in action on our test piece  

the test piece:

The top got really charred from trying to cut test circles, on the bottom we were testing the best distance between channels.  The yellow is the exposed plastic after etching away the copper.  (we etched the paint first, then dissolved the exposed copper, then put it back in the laser cutter to cut the circles)

After removing the paint with acetone, reveling the copper:

While the laser method did work, it was really time consuming and using the lasercutter was complicated and costs money to use.  We went back and re-read about toner transfer and realized we may have messed up the ironing step. We held the iron still and applied pressure, but some internet sources said that you have to apply pressure and move the iron around on the plate to distribute heat, so we decided to give it another shot.