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Double Sided PCB

Posted: Sat Jul 26, 2014 9:32 pm
by scott216
Created my first two sided PCB with my Shapeoko. It came out pretty good. In my PCB design I put registration holes at each corner of the PCB (they get milled away when I mill the outline). I had to edit the g-code so these holes would be deeper (0.25") then the normal holes. I milled the bottom side, then drilled the holes, then I flipped the PCB over and used pins to register the PCB. The pins don't stay there, I use double sided tape to hold the PCB. Then I moved my x-axis zero point to the left - same width as the PCB. I'm using the new touch-plate feature in GRBL (dev v0.9f) to zero my z-axis. This works great, it's so much faster to set my z-axis now.

I'm using a 0.3mm end mill with lots of WD40 on the board. My feedrate is 4ipm and depth is 0.005 inches. I do want to experiment to see if I can go faster. I'm using Cadsoft Eagle with the pcb-gcode script to generate the g-code.

Re: Double Sided PCB

Posted: Sat Jul 26, 2014 10:26 pm
by cvoinescu
That is a superb PCB. Good job!

Re: Double Sided PCB

Posted: Sun Jul 27, 2014 1:16 am
by WillAdams
Agreed. That's one of the cleanest, neatest boards, w/ the most consistent traces I've seen posted here.

Thanks especially for posting your feeds and speeds. I've been thinking it'd be nice to dress that page up w/ sample images --- yours would be a great one to show just what the machine is capable of.

Re: Double Sided PCB

Posted: Sun Jul 27, 2014 3:24 am
by scott216
I was getting ready to solder it and it struck me I didn't take into account the holes are not plated through :cry: Most of the holes are for headers and I can't solder those pads if they are on the top layer. Previous to this all my double sided boards were sent out to be made so the holes were plated through. I won't make that mistake again.

To get good results you need pretty low spindle run-out. I found on my Dewalt DW660 that the collet runout varied a lot from one collet to another.

I read a tip somewhere that flatbed scanners do a good jog for "taking pictures" of PCB boards, that how I got the pictures I posted.

Re: Double Sided PCB

Posted: Sun Jul 27, 2014 2:35 pm
by cvoinescu
Forgot to ask -- is that double-sided FR1? I would like to avoid milling FR4 (out of concern for both my tool and my lungs), so if you have a source of inexpensive double-sided FR1, I'm interested.

Re: Double Sided PCB

Posted: Sun Jul 27, 2014 4:04 pm
by scott216
cvoinescu wrote:Forgot to ask -- is that double-sided FR1? I would like to avoid milling FR4 (out of concern for both my tool and my lungs), so if you have a source of inexpensive double-sided FR1, I'm interested.
It's FR1, got it from Inventables: https://www.inventables.com/technologie ... ard-blanks
Even though it's FR1, dust insn't a problem for me because I have a the WD-40 pooled up on top of the PCB. It just creates this copper/FR1 sludge. I put a border of masking tape around the perimeter of the PCB to help keep the WD-40 contained.

Re: Double Sided PCB

Posted: Sun Jul 27, 2014 5:33 pm
by cvoinescu
I'm not afraid of FR1 dust, but I want to avoid extra-fine fiberglass dust (FR4). I know Inventables carries the double-sided FR1, but I haven't found them anywhere else.

Re: Double Sided PCB

Posted: Tue Jul 29, 2014 5:27 pm
by Auarhau
Great results!

I thought this video might fit in here, since this is the post that pops up on searching the topic. I found it instructional.


Re: Double Sided PCB

Posted: Thu Jul 31, 2014 1:52 am
by scott216
cvoinescu wrote:Forgot to ask -- is that double-sided FR1? I would like to avoid milling FR4 (out of concern for both my tool and my lungs), so if you have a source of inexpensive double-sided FR1, I'm interested.
Othermachine carries the PCB boards: http://store.othermachine.co/collection ... oducts/pcb

Re: Double Sided PCB

Posted: Thu Jul 31, 2014 8:23 am
by cvoinescu
scott216 wrote:Othermachine carries the PCB boards: http://store.othermachine.co/collection ... oducts/pcb
Thank you. They appear to ship only to the US, though.