Gene, Gary, I use double sided tape a lot for milling EPS/XPS foam and sometimes for PCB milling. There is a problem with the tape wrapping around the mill when you mill through the tape, not that much of a problem for PCB material with a spade mill but it could be a problem with one of those combined engraver/drill bits for PCBs. Surely tape is a problem with foam, the tape will stick on the sharp edges and influence the quality of the cut.
A vacuum table is the better solution and easy to make yourself. Although I don't like Andrew's design (it does not allow you to use smaller PCB material) it is nicely made. Check out this link http://www.cnczone.com/forums/showthread.php?t=33585&page=2 <http://www.cnczone.com/forums/showthread.php?t=33585&page=2> in the cnczone, it shows photo's of a home made grid type vacuum table. Nice thing on the grid type is that you can use a silicone or rubber band to create a smaller vacuum area. Made out of PVC it is not expensive, not too heavy and very forgiving in case you drill or mill too deep. And yes, you do need a vacuum pump and the litter wonder that Gene has is a very nice humming pump. Most membrame type of compressor like used in a refrigerator are also a nice, they don't make as much noise as my vane pump (mostly being used to vacumize large 70" x 20" carbon forming molds). When buying a vacuum pump, be sure it is suited for this kind of continuous high vacuum load. Under load the motor may become hot and even a smaller pump may need a cooling fan to guarantee long life. Regards, Rob Gene Heskett wrote: > On Thursday 14 May 2009, Gary Fiber wrote: >> I think some use double sided tape to stick down PC boards. I read on >> someone's site he used Scotch 667 double sided tape so I got a roll >> and will try it. Others use carpet tape. >> > > I may give that a shot. Obviously clean the table off with alky first so the > tape will stick. :) > > >> Others use vacuum clamps. Have a look at http://www.drewtronics.net/ >> > > Neat, and wonder of wonders, I actually have one of those little pumps! > Hummmm... > > ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
