hey all im new.

ZOMGAZOMG N00B QUESTION ALERT!!11

what is a CNC machine? is it a thingy that cuts metal and plastic?

Ahoy thar! A CNC machine as a machine tool that uses Computer Numerical Control. It's essentially a programmable machine. You write a program for it or have one generated by a tool. I'm oversimplifying but the program essentially consists of a set of points and rates. You're telling the machine to go to ceartin points at ceartain times. By going there you're cutting away material using the tool. CNC allows to extremely precise parts to be made very rapidly.

Welcome! Are you folding with us? CNC is fantastic. Billy explained it pretty well, but it has particular interest for hacking because while the principle is simple, the machinery required to do it cost a lot. That's why I love the homebrew stuff, because they are doing things that would require a commercial machine worth over $20,000.

but, then the commercial cant sell really good do they?
and that laser thing, where do i get one of those and what else can i use other than a lazer?

Well, most places who need a CNC machine deal with the price, after all, what machine shop is going to spend time building thier own CNC?

If your talking about what I think your talking about:
Industrial Lasers R US
And it'll run you 15k

Most people use a type of physical bit (similer to a drill bit i guess) and usually a lubricant to keep it running cool. But i'm not a CNC person, you should ask around in the CNC sub-forums.

High speed tool steel bits work great with a little coolant. Also, the commercial machines are sold to machine shops that need to have proven reliability and someone to come fix it if it screws up. Nothing that we ever build is going to be found at a professional machining shop, because especially on those machines time and tolerance equals money. Our machines are too limited and simple to do some things that the large industrial machines do.

hmm, those CNC machines sound pretty neat.
i have found out that i want to build me one out of a pen plotter.
but where do i get a pen plotter? is my best try the junkyard?

das ebays are always a good place to look for oddball stuff.

but i live in norway, and im like 16 and my parents totally freak out if i buy something from another country on like the net...

and if i do find one, what will i use to cut? i mean, i know like its good with a dremel, but i only have one dremel, and i cant afford another one? or, the one i have is the real one, the one that is made my Dremel@TM.

is it any cheap dremels i can use?
or, when i think of it, i do have another wannabe dremel tool, but its kinda bigg and stuff, but maybe if i like put it in another case or sumthing i might make it smaller, il check that out.

There are plans to build one where you simply mount the Dremel on the tool, and then take it off when you are done. Here are some plans that might fit the bill for you; http://www.crankorgan.com/

i didnt find the plans? when i press plans the pictures of all his stuff come up, and when i press them, it just goes to the place where he desribes them, but i will definetivly use a mechanisme so i can remove the dremel, unless i can make my other noob dremel smaller...

but where is a good place to look for old pen plotters?
other than ebay. i think i will make me a trip to the junkyard soon ^^.
and maybe the store that gets stuff from the younkyard.

He's charging for the plans. You'd have to click "Order" and order a set.

garr.
but is it posible to use old printers insted of a pen plotter, because here in norway (where i live) i have never seen a pen plotter, and i have never heard of anyone that has one, and besides that, i have never seen one at a flea marked/garage sale (wich i go to quite a alot).
so i doubt that they are many of them here i Norway.
and i just got my hands on 2 old (10 years or more) printers.
maybe scanners or kopy machines are better?

I don't think you'd every find pen plotters to be common in flea markets regardless of country of residence. It's the kind of thing you might have to know somebody to get easily. You might wish to check with vocational schools and larger companies with well-established drafting labs such as those in the heavy machinery and aircraft industries.

the search for servos really depends on how deep you want to get into it. You could use the servos out of a dot-matrix printer if you needed to but the more oddball the source gets the more elbow grease it's going to take to figure out how to make them understand your programs.

Perhaps I should split this thread off into the CNC forum.

EDIT: Done with intarweb magics.