[hcker2000]

I am looking to build a small cnc to mill pcb's with as I do a lot of electronics. I need to be able to do a 6 inch x 6 inch area.

Some thing like this is very close to what I need.
http://kidvideos.blogspot.com/2007/0...-cnc-mill.html

I just want to get input and find out more about what step motors I should look for for the xzy movement and what controller is easy to build.

Thanks in advance.

[jalessi]

You will need to know a little more about the weight and resistance of your machine before making a stepper motor purchase.

The Hobby CNC controller is a very good quality, ez to assemble, economical choice.

Jeff...

[sansbury]

I built a "Brute" from the plans by John Klein bauer for this exact purpose. Google that and you should get his site. A bit of an eccentric but his plans have stood the test of time and given birth to probably more finished machines than anybody for something this size. It's easy to spend hundreds on false paths so $30 for proven plans is a good deal in my book.

Accuracy to better than .005" is possible if you're careful. Mine is good to at least .008" and I can just barely send a signal between IC pins which is really the acid test, unless you're doing SMD stuff.

A PCB router running with ordinary hardware store 1/4-20 rod (as mine is) does not require much motor power at all. 60-oz motors are quite sufficient given the 20:1 reduction. It's hard to buy motors under 125oz and with those I can zip around at 60ipm which makes the little machine look almost industrial. Watching it drill out a hundred #70 holes is fun!

The HobbyCNC controller in my view is the best deal going.

FWIW, my machine did a great job, but I came to hate homemade PCBs. It's a better process than etching, but at the end of the day you still don't have soldermask or plated through-holes. When you look at what services like Batch PCB cost it just didn't make a lot of sense. I'd happily sell you my mill and you can bolt some motors on. PM me if you're interested.