Comments on: PCB Milling with the MakerBot CupCake (Almost)

By: Darin White

Darin White — Mon, 07 Mar 2011 21:34:32 +0000

Keith, I’m using a 60 degree v-shaped bit. It’s a hand-me-down used bit from a friend that runs a pro LPKF mill. For pro purposes the bits are swapped out after so many inches of cut, but for my less-discriminating and low-budget application these are fine. Obviously with the v-shape I need to be careful about how far I plunge into the copper as the cut gets wider the deeper you go. This causes grief where traces are tight together and the toolpath out of pcb-gcode is fixed at a certain width. I know 45 degree v-bits are available and would be less sensitive to this phenomenon, but no experience with those.

For a different spindle design, check out Dave’s work: http://makeyourbot.org/ on the Mantis 9 mill. If I had better shipping rates to Canada from http://www.sdp-si.com/ and http://www.mcmaster.com/ I would have already built one of these.

Really like your site. It’s a must-read in my RSS feeds.

By: Keith Neufeld

Keith Neufeld — Mon, 07 Mar 2011 21:07:15 +0000

Darin, great-looking boards and nice job on the meticulous improvements! I’d love to find a spindle well-balanced enough that it doesn’t require remote mounting, but I’ll keep that in mind.

What’s the bit you’re using in the picture above “The tie wraps work well?” I like collared bits, so I might be interested in trying some of those.

By: Keith Neufeld

Keith Neufeld — Mon, 07 Mar 2011 21:04:06 +0000

Pierre, I just ordered a set of bits from the same seller on the US eBay site. Thanks for the pointer!

By: Darin White

Darin White — Mon, 07 Mar 2011 19:16:28 +0000

Hi Keith,

I had better results when I mounted my Dremel off my mill on a bungee and connecting a flex-shaft to the z-axis. The reduced vibration made a huge difference in cut consistency. See this post:
http://www.kwartzlab.ca/2010/06/pcb-cnc-mill-rocking-out-board/

By: equinoxefr

equinoxefr — Mon, 07 Mar 2011 18:54:14 +0000

Hi,

You can use carbide engraving bits from ebay. Ex: http://cgi.ebay.fr/5-Carbide-PCB-Engraving-Bit-CNC-Router-Tool-45-0-1mm-/250768483594?pt=LH_DefaultDomain_0&hash=item3a62f7650a

If you can, buy high quality bits, epoxy on board is hard for your tools

Pierre

By: Keith Neufeld

Keith Neufeld — Mon, 07 Mar 2011 15:29:43 +0000

Andy, 1/64″ is a little over 15 mil, which is a pretty large inter-trace distance on some of the boards I make. I hope to find a pointed-tip bit with which I can make narrower isolation cuts (when desired).

The Make Your Bot guy does seem to have a pretty effective spindle setup, though! I might give that a shot if nothing else pops up first.

By: Andy Soukup

Andy Soukup — Mon, 07 Mar 2011 15:16:41 +0000

You can buy 1/32″ and 1/64″ end mills on ebay for like $10. I’m working on building a PCB CNC from scratch that is based off of http://makeyourbot.org/start (and by $100 CNC, he means $300)