Homebrew PCBs

I have watched this PCB milling discussion with interest.  I have neither the time nor the inclination to attempt to make a PCB mill.  I could use one however for very small quantity commercial work I do here.  Realistically, what are the low-end options that are actually viable (not mere toys)?  I would consider anything up to maybe $5,000.00 to not be outside the realm of reason, but I understand some of the commercial machines can be $12,000.00 or more, definitely outside of my budget for this project.  

Any guidance on realistic options would be much appreciated.

Syd

  ----- Original Message ----- 
  From: Dave Mucha 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Monday, January 01, 2007 7:53 PM
  Subject: [Homebrew_PCBs] Re: First efforts with isolation milling and the new machine....


  Hi Chris,

  You are correct that Z depth is very important. As is spindle run-out.

  Some tips to try in the early stages.

  #1) do only single sided as you are getting used to making boards.

  #2) never try to run a trace between pads if at all possible.

  #3) make all the traces as wide as possible. shoot for 50 mil.

  There is a feature called rub-out. that will remove all the copper
  around things. it will take forever to do the whole board, but in
  places like a set of dbl row header pins, it is nice to have only
  pads, and not the little diamonds.

  As you found out, depth of cut is vital. I run the cutter along the
  edge of a board and feed it down until it just touches the copper. in
  some cases, that will actually penetrate the copper.

  A spring set cutter and a foot type stand-off will allow you to
  eleminate the Z axis from the work, however, it probably will not work
  with your tool changer.

  http://www.2linc.com/engraving_depth_controlling_system.htm

  expensive, but it might be possible to make your own.

  as you get better making boards, running traces between pads can be
  done. the feel for the depth stop is the key. if you are getting good
  depth control, your traces will be of uniform width and your between
  pad, traces will be reliable.

  The single sided is really just to eleminate the frustration of
  getting the back of the board wrong and having to start all over again.

  I really am envious of your tool changer. great idea.

  Dave



   

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