Announcement

Collapse
No announcement yet.

I found a new (to me) use for the CNC

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • I found a new (to me) use for the CNC

    A new project, turned biz, had me out looking for a firm to do small, but simple PC boards. As we are on a short start up budget, and the board is a very small part of the device, we only need runs of a few dozen at a time. Understandably, the local shops doing such work required to much $'s for them, so it was time for plan B, do them ourselves.

    I made a few prototypes with the etch proccess and found it very time consuming aligning the parts to be soldered correctly. Six of the 8 parts require high accuracy in their locations in order to fit nicely through holes in the face plate when it is attached. The etching proccess is also messy and time consumming. Time for revision 1 to plan B...

    Around 2:00 am it hit me in my sleep (naturaly). Why not make the entire PC board on the CNC, and do so complete with tiny little pockets to line up all components for placement. Copper clad board is .07 thick (including the copper). I am pocketing .03 for components and .01 to remove the copper where needed. I nest the parts and can complete 24 boards in about 40 minutes. One trick is to not try to remove ALL the copper that is not needed. Just cut a line between parts not to be connected and leave the rest of the copper on the board so as to not waste additional cutting time. Holes are all done in the same cycle also.

    Maybe this info can be of help for some of you.
    Stay Safe

  • #2
    One more thing on above post guys. If going to use the mill to draw with resist ink for etching a board, be certain to set your Z offset correctly. The resist ink markers make a huge mess when its driven into the work peice.
    Which brings up a question. If it makes a squishy sound instead of a big crunch or bang, is it still considered a crash?

    If so then consider me crashed.

    [This message has been edited by lotsa luck (edited 04-12-2005).]
    Stay Safe

    Comment


    • #3
      <font face="Verdana, Arial" size="2">Originally posted by lotsa luck:
      One more thing on above post guys. If going to use the mill to draw with resist ink for etching a board, be certain to set your Z offset correctly. The resist ink markers make a huge mess when its driven into the work peice.
      Which brings up a question. If it makes a squishy sound instead of a big crunch or bang, is it still considered a crash?

      [This message has been edited by lotsa luck (edited 04-12-2005).]
      </font>

      There's a guy I used to work with that somehow scavenged such a thing from one of his previous employers. It looked to me less like a mill and more like a flatbed plotter, but with a Dremel-like thing in the head, with a very small milling-type bit. It was hooked up to a PC printer port, and used to make short runs of prototype circuit boards. I've seen finished product, and it looks a little different from the average PCB because you don't need to remove *all* copper, like you said. One problem I envision, however, is that you might want to protect the remaining copper somehow. (Fabricated PCBs are plated all over with solder and/or gold, usually)
      Otherwise, for small runs, I'd say you've hit upon an excellent solution. OTOH, when you can run the budget up a little, check out the following:
      www.expresspcb.com

      Ya download their special software, lay the board out with it, and then use the result to order boards online. I use it for my home-project prototypes when the board is fairly simple. Last I checked, there were certain size constraints, but it's quick and cheap for what you get.

      -M


      The curse of having precise measuring tools is being able to actually see how imperfect everything is.

      Comment


      • #4
        Thanks for the link, but the locating problem of the high output LED's would still be a problem. These LED's are not standard to any current parts size/layout they have in the program and MUST be located an accurate distance from center point of the board. Costs need to be under $.50 per board prior to component placement. Also, the entire board is potted into place for water proofing so the board gets embeded in potting compound thus needing no corosion protection of the copper.

        Thanks again for the link.

        [This message has been edited by lotsa luck (edited 04-12-2005).]
        Stay Safe

        Comment


        • #5
          Been there, done that, worked great; it is, however, slow... (I use my MaxNC 10 for this)

          Comment


          • #6
            From the little I know cnc board were done like this for quite some time aleady, Now the spray on layering paint teunique is the cheap way to go. Or so ive been told.

            Comment

            Working...
            X