[hesslerk]

Looking for some plans/tips on how to make a desktop CNC to carve traces on a PCB and drill out the holes as well. Any help would be great!

[Rhodan]

Use 1/2-10 ACME screws with Kerk (style) anti-backlash nuts and you won't really need anything beyond a full step controller. Each step is 0.0005" which is fine for circuits. The nuts are pretty cheap too - Dumpster, Kerk, or the kerk-alikes at McMaster carr would all work.

Other than that don't freak about getting a massively sturdy machine. Just figure out the largest PCB you'd want to make and size to that. 12"x12"x3-5" should be plenty to do PCBs and enclosures/front plates and the short travels allow the use of lighter materials without deflection getting in the way.

If you want to tackle harder metals then I'd suggest going commercial. The K2 KG-1414 would be righteous for PCBs while also being very solid for aluminium etc. http://www.k2cnc.com/Machines/CNC_ro...414_detail.asp

The KT-1414 would be great for PCBs but not great for Alumunium (other than cutting aluminium sheet for front panels). The unsupported round rails just aren't stiff enough. I have the KT-2514 and believe me, the round rails aren't stiff enough. I replaced the 14"x3/4" round rails and bearings with SPB8 OPNs and supported rails already and, when money permits, I'm putting HiWin rails and trucks on the 25" axis. Then I'll try solid aluminium again.

See the "The bit was HOW small?" thread to see the 2514 in action.

If you want to do good PCBs then thats the spindle you want - wood routers are simply not going to work worth a damn and the dremel-style tools have too much runout. The Wolfgang spindles run ~$250 with mounts and AC motor.

Get a few 0.0100" stub endmills (the less pointy ones) from Think & Tinker (try a 0.005" if you like, but its hard to solder without bridging over the 0.005" cut) . http://www.thinktink.com/cgi-bin/car...ep=20&start=18 0.01" bits will let you fit up to 0.02" traces between 0.06" pads. The 0.005" lets you fit two 0.012" traces between pads (but better be good at soldering or cleaning up bridges).


Hit Drill Bit City and order a couple of Circuit board maker kits (the 90 degree bits aren't really needed for PCBs but can be handy if you want to engrage brass or something. Also grab a pack of 0.063 carbide router bits. They're perfect for routing holes larger than 1/8" and cutting out boards or slotting. Think & Tinker have them too but at ~$40 for 10 instead of ~$25 for 10.

http://www.drillbitcity.com/catalogue/special_tools.asp

It can also be handy to get the http://www.drillbitcity.com/catalogu...g=102-10W59-50 #70s drill bit set for larger holes. Dont need them all that often but fuse holders and power jacks generally fall into this size range.