CNC build few snags

[Papa_lazerous]

After toying with the idea for far too long I am finally going to build my own CNC, I've spent long enough working on them that I figured my own one at home would be ideal for me.

I make allot of pcb's at home using a UV light box to expose and its a time consuming method, I already know how to post G-code from Eagle and I also have Gibbs CAM so I am set on the programming side as thats what I do for a living.

I am at the early stages of design, I will be going for a gantry style mill/router with moving table and fixed gantry. Got some sketches worked out already, although I can't get anything too solid designed as I have a stumbling block already.......Hey you knew it was coming or I wouldnt be hear asking right

I found a seller on ebay that seems to have some pretty good deals on linear bearings so I'm sorted there.

Spindle wise I really dont know whats available, sure I have a dremel but I am thinking I will want something with a little more power as its gutless.

Also from hours of googling I am pretty sure a NEMA 23 motor would be perfect, the whole uni-polar bi-polar thing is a little bit to take in also, from what I understand bi-polar is better for me

Driver and power supply, I am sure I found a site a while back that had loads of information on power supplys motors and driver boards and was based around using PIC microchips to drive them, that would be ideal for me as I have a PIC programmer and a stash of PIC's cant find it for the life of me though.

Also lead screws, I have seen some very basic designs using threaded bar, simply a length of M14 studding and a nut, Any of you guys use ACME or ball screws? if so are there any sources out there for something suitable for me? I have only found ones that are for full size machines

I dont expect anyone to jump in and type an essay and reply to all of this, but if you can point me in the direction of some links or have any good information I would appreciate it. Just seems google is great for finding sites where people want to sell me stuff

[harryn]

Hi, if most of your work is pcb oriented, then here are a few links (for more reading of course)

a) A section of this forum specific to pcb milling.

http://cnczone.com/forums/forumdisplay.php?f=403

I suggested reading through the posts and experiences of cnczone members Jay C and pminmo, as they seem to have their hands deep in this area.

b) A small web site specific to pcb milling.

http://millpcbs.com/

Sorry for not being more specific on the equipment specs, but these posts are from real world users with real world good results.

PCBs are actually a really tough test for machine performance, but the nice thing is that usually it is over a relatively short range.

Good luck,

Harry