View Full Version : X3 cnc conversion questions

12-23-2009, 02:42 AM
I'm trying to get a good understanding of what all is needed in a X3 mill cnc conversion, been doing alot of reading but it hasnt all sunk in yet.

From what I can gather- The computer is connected to the breakout board, which the motor drivers are wired to, the drivers control the stepper motors.. Power supply is needed for the motors, and then a small 5v PS for the breakout board?

This kit #1


Plus this stepper motor kit


And then a comp + Mach 3 software..

Is there anything else involved for a basic cnc conversion?

Also, Ballscrews or stock mill leadscrews. Is the extra cost of getting ballscrews worthwhile for a hobby mill? I understand there is less slop/backlash with ballscrews but what kind of tolerances would that equal out to on machined parts compared to leadscrews?

Thanks again!!

12-23-2009, 03:22 AM
There was an excellent set of articles in the British Model Engineers Workshop in about Nov 2004, over three issues. It detailed drive motor selection, the fitting of ball screws, and the construction of the electrics. It used a Desk CNC driver card and a later article in March 2006 discussed some tests on another completed unit.

If you can't source the articles, I may be able to assist.

Let me know if I can help

12-23-2009, 08:08 AM
Try this link


12-23-2009, 08:23 AM
I think you are on track. The connections work like this.
Computer---Breakout board----Driver boards-----stepper motors.

The breakout board usually requires a 5V or 12V power supply. The driver boards require another (Single) power supply up to 70 volts depending on the size of the driver boards and the stepper motors. All three stepper motors can run on one power supply.

I see no need to spend money on "CNC kits". You can buy breakout boards anywhere...(Ebay). Same with steppers. It is best to stay with 4 wire stepper motors. I have been using Gecko driver boards because they can run up to 70 VDC. Gecko also has a breakout board. Gecko has great customer support and instruction sheets for setup.

Link to my projects:


12-23-2009, 08:41 AM
If you're just starting out I'd stick with the supplied acme screws on your mill and build up from there. It's much simpler that way. Later if you want to convert to ballscrews you can. It is really alot simpler than it appears. I used Bob Campbells breakout board just because it seemed a lot simpler to deal with.
If you use gecko drives read the online tutorial on their site. I will prove to be a vakluable resource specially when building a power supply.

12-23-2009, 01:01 PM
Thanks for the replies,

It is starting to sound fairly straightforward now. All I saw before was websites full of boards, drivers, motors, controllers, PS's etc. Without having a general idea of what did what made it pretty tough to get an idea of what was needed.

I'll do some more reading on the links provided, hopefully my next questions wont be as basic!

12-23-2009, 02:07 PM
Yes, It's easier to start out with a simple conversion and upgrade as your experience and budget allows.
With Stock Acme screws your rapid speeds will be reduced and backlash might be a bit of an issue. But they will be fine for hobby work and to allow you to get up and running quicker.

The x3 is a small machine and so don't need to spend a lot of money on steppers and drives.


12-23-2009, 06:06 PM
I use Rockford Ballscrews.


Their 5/8-5 rolled ballscrew is least expensive and accurate to +/-.001 per foot. Pretty good for hobby stuff. Their standard ballnut has .004 backlash. Order the ballnuts with oversized balls to have .001 backlash. Ballnuts and screws are hardened so they should last a long time. The ballnuts have a 15/16-16 mounting thread. I also made my own ballnut mountings.

Rockford Ballscrew will cut the ballscrew to length and anneal the ends for machining. I ordered a 6' length of ballscrew. Cut it to length and annealed the ends with a torch myself. I bought the last ballscrew and nuts through Motion Industries then drove to the Rockford Ballscrew to pick them up rather than pay shipping.