I am in the process of a CNC conversion and thought id share what i have. Comments are welcome!

Im using the 4030's from Keling and the 425oz motors. Everything is powered with 3 computer PSU's in series for 36v. The power supplies are controlled with an optoisolator board that I made for this project

Folder of pics here: http://www.rfhv.com/cnc/

http://youtube.com/user/cr99991

Looking good!

Jack

Looks like it's well on it's way :)

The z axis is always the biggest pita when converting an X2. Your method is much like the cncfusion idea. Are you planning to go 1:1 with the z or use a belt and pulleys to get some other ratio? The ballnut mounting block doesn't appear to be threaded, curious how you plan to mate those pieces.

I copied the counter weight idea shown here this weekend
http://www.cnczone.com/forums/showpost.php?p=467241&postcount=63
Cheap and effective.

What type of ballscrew system are you using? Have a site or anything form them...


-Jason

Thanks for the replys.

The motor will be mounted directly above the ball screw shaft with a 1:1 ratio. The ballnut mounting block is actually threaded for the 15/16-16 ballnut. I had not planned on using a counter weight but if my motor has problems moving the head, I may use an air spring.

My ballscrews are from McMastercarr. I probably should have gone for the Roton ones because they look a little nicer, but I think the one I have should get the job done.

How much backlash ( if any) do you have on your ballscrews?

I did a conversion on my lathe with some screws similar to yours (mine are Thompson) and found .005" backlash. I'm going to put a double nut on my z-axis and replace the balls in the x-axis nut with larger balls to take out the backlash.

Cheers,
Jack

I am only using a ball screw on the Z. The X and Y are stock. I have no idea how much backlash my Z screw will have tho. Hopefully the weight of the head will make the backlash less of an issue. I have about .006" of backlash on the X and Y, but mach 3 seems very good at eliminating it.