[xante]

I've decided to take the plunge and build my own vertical cnc mill. I have several HP Laserjet II's, IID's, and III's for their stepping motors. I also have several older pc's to control the mill, computer power supplies to power the motors and a dremel tool for the spindle.

My questions are, will the stepping motors have enough "resolution" to do engravings and cuttings of names, images, or to actually make a part (probably from T6 aluminium .125 - 190").

Also what controller should I use, I looked at http://members.shaw.ca/axxus/db1v20.htm and think that it might be ok for me, but not sure if it will work with the HP motors.

Any help or comments would be highly appreciated.

[mvaughn]

I'm pretty new at this so the more knowledgable members may need to correct me on this one.

The steppers found in most HP Laserjet II and III series printers have a 200 step per rotation resolution, or 1.8 degrees per step.

If you use 1/4 - 20 all-thread as a lead screw you would get 20 turns per inch. It would take the stepper 200 steps per revolution, times 20 revolutions, or 4000 total steps to go one inch. That would be a theoretical resolution of .00025 inches per step

If you used 1/2 - 10 ACME thread would yield .0005 inches/step

As far as that controller board is concerned, I don't think it will work directly with the HP steppers or any other stepper. I believe that that board requires individual drivers, such as geckos, for each stepper. If you read the page for that controller it explains the requirements.

You may also want to check out http://www.hobbycnc.com/ and our open source controller forums. Pminmo ( http://pminmo.com/ ) and Tachus have some great designs.

[xante]

So I would buy that and a "driver"? So basically the paralell component is just a adapter to send commands to drivers? Sorry that I'm such a newbie at this.

If I get the DB1V2.0 CNC Parallel Port Interface and the Geckodrive stepper, would I be able to move the stepping motors? Or would I be better off with a kit from one of the pages you showed. I want to keep this on a very low budget as I don't have much to play with.

[ger21]

The Axxus DB1V2.0 is a breakout board. Here's what you need. A PC. Controller software, which takes g-code files and sends signals to your drivers. Most people here use either Mach2 http://www.artofcnc.ca or TurboCNC http://www.dakeng.com. There are others as well, but those 2 are those most popular. Then you may or may not need a breakout board, which plugs into your parallel port and usually has provisions for limit and home switches, and possibly relays, and also routes the step and direction signal to the drive(s). The motor drives take the step and direction signals from the controlling software, and actually run the motors. These will require a power supply. There are several alternatives to Geckos, especially if your using steppers from old printers. Both HobbyCNC http://www.hobbycnc.com and Xylotex http://www.xylotex.com sell unipolar chopper driver kits that you assemble and should run those steppers very well. Both are under $100, for up to 4 axis, and neither require a breakout board. But you can use a breakout board with any drive. Geckos would be able to give a little better performance because they would allow for a higher voltage power supply, but would not be worth the extra expense, imo, unless you were using higher performance steppers.

[mvaughn]

Well said Gerry, I would also like to add that it will be helpfull for you to do some searches here on words like xylotex, hobbycnc, unipolar, chopper, picstep, etc...

These keywords will result in tons of information about driver boards. Since you are budget oriented you should read as much as possible before buying any electronics