Newbie to CNC, could use some advice.

[Blacksunshine]

Actualy I am not new to CNCs, ran a rotery 600w laser cnc for 6 years.

I enjoy it so much that I would like to be able to do something similar in my shop.

My question/delema is do I purchase a CNC system like torchmate etc or is it more economical to build one my self?
Either way I go I dont have a clue on all the components I need to make a CNC operate. I see some kits on ebay from germany that look nice but its just the bare bones x,y and z, after that I dont know what I need to make it run.

I would like to be able to have a CNC 4'x4' and at least a 5" or better z axis.
whats better to do? buy a system or build a system?

any help on this would be great since there seems to be a lot of profesional in this forum.

[project5k]

ok, let me say this first, im a total noob, i dont have a working machine, i havent used a cnc machine, and im definately no pro...

now that having been said... i'm building my own machine... most of the folks on here will caution you to start small, get that working, and learn what makes it tick, then go to a larger machine... me, im not one to do things in stages.. and yes this has cost me at times, but my personal opinion on weather to build or buy is dependant on your abilities and budget.. if you have the $$ and are in a hurry, then do some homework, see whats out there, decide on what you want the machine to do, and then add some for the future, and decide on a machine and write the check...

as for me, i dont have the big $$, but what i do have is a solid understanding of mechanics, electronics, a welder, and a dream... so i'm building my machine.. i'm also not starting small, im going to go at least 4'x4'x6" working area to start, i would prefer to just go 8'x4'x12" the first time and be done with it... but im in the design phase right now... I have built one of my driver circuits.. its a L297-L298 type, 2 phase bipolar system.. my motors arrived today, but were damaged in shipping... you can see http://www.jpcustomcrafts.com/badshipping.htm to see what the men in brown can do to some really nice parts....
you can see my thread off the wall nooobie design ideas to see the path i went.. first thing to do is to take stock of what you have, both in materials, tools, skills, and $$... then decide what it is you want, or really need, figure in some room for growth, and weigh it out like that... if you just take off into this and dont do some real hard thinking, some serious planning, and some pro/con tables, you might end up with less $$$ more frustration, and something that isnt fit to carry to the dumpster...

looks to me like your starting out right, getting on here, reading, researching, and learning...
the basics of a machine look something like this....
motors, to make things move
some way to turn that rotary motion from the motors into linear motion... this could be screws, belts, chains rack and pinion... depends on the accuracy you need and your $$$...
the machine, this includes guides, rails, bearings, metal or wood, depending on how strong you want it and what your gonna cut with it...
something to do the cutting, this could be as small as a dremmel, or some kind of big power spindle, or maby you would prefer a plasma table... then you gotta have the plasma cutter power unit and some kind of torch...
then theres a computer, and software... now on this, and well with all of it there are options.. but basically you'll need 3 things.. cad or something to draw what you wanna make, cam to convert this to g code(the language of the cnc machine) and an interpreter controler software... this takes the g code, translates it into signals that the machine can follow. i have 2 of these decided on... my cad is rhino, cause i already had it... and my interpreter is Mach3.. simple, powerfull, and reasonably priced at about $160... i havent decided on the cam yet, im still researching this....

and last but not least there's the drivers...this is what takes the signals from the computer and interpreter software and make them strong enough to actually run the machine.... there are options here too, but this and your motor selection go hand in hand.. as you read and learn more you will find that there are lots of different types of motors, drivers and so on... i prefer steppers, just cause there cheaper and i understand how they work... servos would be more expensive, but have theier advantages...
with a stepper system, you can build your own drivers, or you can buy, i have heard (but have no experience) that gecos are a really good option, but are about 2-3 times the cost of home built...

the bottom line is what do you value your time at? if your willing to learn, and put in the wrench time, i really think that you will find it cheaper in actuall $$ to build... plus i just really enjoy tinkering, so its relaxing, educational, and a great excuse to be out in my new 2400sqft shop... if i had the $$$ yea i'd probably write a check..i'm impatient, but then i wouldnt know every bolt and nut, and noise, and quirk of it... theres a certain level of pride when you build something, stand back and say " I DID THIS"
ofcourse, i allways follow that under my breath with "and i shoulda done this and that and the other thing and not done this other..."

sorry for going on and on, just got started on a line of thinking and started typing