jamie32
09-21-2007, 12:58 PM
I am a college student trying to make some simple electronics. Currently using laser paper transfer method and dremel to make my PCB Boards.
I would like to know who are the cheapest and best CNC PCB Milling machines? I want a mini cnc mill that is designed for small items/circuit boards. I have about $800 bucks saved up for this so price is a big factor.
http://www.sherline.com/images/5400DROpic.jpg
5400DRO By Sherline Mini CNC Mill company?? Any good?
I am also looking for a cheap place to find the wafer boards for simple circuits/projects.
Thank you.
Stepper Monkey
09-21-2007, 04:07 PM
What spindle speeds are necessary for PCB work? I seem to remember it's pretty high. That would probably be the big limitation, as beyond that really most any mill could handle it.
If you are only going to be doing circuit boards and plastics, I know folks often use the Proxxon MF70 for PCB's. They are only a few hundred bucks and take like 10 minutes to convert to CNC. You can even use Nema 17's on them, and they are practically given away as surplus or on Ebay as they are too small for bigger metal cutting mills.
jamie32
09-21-2007, 04:23 PM
Ive read that 3600 RPM is great for PCBs. Do you know a tutorial that explains how to convert Proxxon MF70 to CNC? thank you a lot!!
Stepper Monkey
09-22-2007, 02:59 AM
There is a tutorial video on YouTube - in Italian if I remember correctly - that shows a person doing a conversion in real time. It is about ten minutes long. It is showing how to install thier own pre-made parts, but you can easily make your own adapters in a few minutes. It isn't rocket surgery on these little things.
There are a number of European web sites that show conversions as well, and one that I found in English is here; http://www.indoor.flyer.co.uk/millingmachine.htm
Another really rudimentary one is here; http://www.timgoldstein.com/cnc/Proxxonconversion.asp
In general, I think the mills are a little under $300 new if you shop around. The drivers and steppers can be very small, and therefore very cheap as nobody can use them them for regular machining. I have found new size 17 motors and size 23 half-stack motors on Ebay for 5 bucks or less each, and if you can't find any good deals I have a pile of Vexta 45 oz/in motors left from scrapping old equipment you can have free if you want. They would be about perfect for a mill that size. Just about any driver board will have more than enough power. Power supplies are also easy, as the unit only draws a few amps, so even old laptop bricks will work and should be available for about $10 used.
All in all, depending on how handy you are and how much you want to shop around, you should be able to put together the complete mill for $400-odd bucks or so. For what specific stuff you want to do I think you can probably even get away completely with free software as well.
askman
09-22-2007, 11:50 PM
I had lot of luck with taig cutting pcb material. run it at 10000rpm though it likes higher speed. you need to run high speed to cut/drill pcb.