I have started this thread to document my adventure in building my first CNC machine. The primary use of this machine is to help me build an even bigger 4x8 plasma/torch/router table.

What got me really interested in building a CNC machine was when I converted an old plot printer into a vinyl cutter. I still use this machine to this day. Strickly hobby stuff.

My mill/drill/lathe is a central machinery. I know that this does not have a very good reputation for being a cnc machine base, but it is what I have. It runs really really smooth. A lot of time has been spent cleaning it since I received it.

The steppers that I am using are a little under powered. They are MAE (PennMotion.com) 3 amp unipolar steppers.

I am using a Delegrange Technologies, 4 axis driver that is good to 10 amps. I have met Dave Delegrange and he is fantastic. Tech support has been wonderful so far.

I will removing the ACME lead screw and replacing it with NC 7/16 lead screw with my own anti-backlash nut configuration. Thurst washers, etc will be used. This will be a direct drive system.

Once this project is complete, these motors will be removed and 800-1200 in/oz motors will be put in their place (depends on the success of this project). These motors will then be used on the plasma/torch/router table.
These are just what I could afford right now.

Money is an issue with this project. I am a middle school computer science teacher, and my wife has a fit when I spend any money on such things.

Please give me any advise where you see fit. Please realize that I know this is not going to be an "ideal" setup at first, just one to get going.

The following pics are components that I have aquired so far

As a point of reference, this pic that I stole off the forum front page is the style of mill that I have. Color is different but everything else is the same.

Do you reall need 800-1200 oz/in steppers? I have a Sieg/HF mini-mill with 276oz/in steppers and ballscrews, and have more power than I need. It snaps endmills way to easy.

My strategy would be to try to procure ballscrews to replace the ACME's and better lower torque steppers, than your 800+ spec.

Automationdirect.com's spec sheet for it's 276 and 400ish steppers show the 276 having as much or more torque in the rpm range where you would actually be maching with.

The 276's are $39.00 plus shipping each. Sneek in one a month, and by the new year you've got all axis's done!

I bought my ballscrews new, but if you are digilient about following ebay, you can find them cheaper.

The main thing is to turn the stepper in the meat of it's torque curve, go to fast and steps will be lost. With ACME leadscrews/ 10tpi or more, it's very tempting to crank up the feeds, and then the chance to loose a step goes up.

Kinda blathery here, but I had to take some meds for this damn migraine.

Rod

Are you direct driving your steppers?

Jon

X and Y - Yes, http://www.cnczone.com/gallery/showphoto.php/photo/1418/cat/500/ppuser/6377

Z, 2.1-1 belt reduction. I didn't really need the speed, and wanted the extra mechanical advantage for the head. I do NOT have it counterbalanced, and I have had very few problems this way.

Rod

I stopped by my favorite surplus electronic store last name and talked them into 50 cents a piece for these connectors. I hope to use these 6 pin mic connectors as my motor connectors to the controller.

What do you guys think. I have had a difficult time finding amp ratings for these connectors, but feel good they have to be good for at least 4 amps.

J