a marble shapes cutting lathe


Thread Starter


i want to cut revolutionary marble shapes with a disk coming from above the workpiece.
i'm trying to make it a 1-axis motion,by making the Z vertical displacement function of the current of the cutting disk; and the Y horizontal displacement function of Z.
Y:servo motor Z:asynchronous motor.
how to do it, knowing that sometimes i have 2 values of Y for one value of Z (case of a vertical cut in the workpiece), which means that no displacement in the Z direction while there is a current turning the disk.
any idea?? thx

Cameron Anderson

I have been reading your post over and over and am trying to make some sense of it. This is what I understand:

You have lather where you have a block or cylinder of marble in it. As it rotates you want to bring a circular cutting disk into the marble, but the speed (rate of displacement) it feeds into the part will be based on how much current the cutting disk motor draws? Horizontal displament will be a ratio to the position that the disk cuts into the part?

If I am understanding correctly, the best solution will be 2 servo drives in a Master/Follower mode. The Z-Axis is probably a leadscrew slide? On the slide is your cutting disk/motor assembly. You will your Y-Axis stage mounted to the Z axis. XY Stage assembly, just tipped up so that one is vertical and the other
is horizontal. Y-Axis will also be a servo.

You will need a current sensor on the Cutting motor that gives us an 0-10V signal. This will come into a the Z-Axis servo drive. The Z-Axis program will do an indexed move where the velocity will be changed on the fly from the analog feedback. When the current is high, then we slow the velocity and vice versa.

The Y-Axis will gear off of the Z-Axis at a set ratio. When the Z-Axis moves, the Y-Axis will follow.

You should beable to do this with several different Mfgs.

1. Emerson En Drives with FM-3 modules.
2. GE Fanuc S2K Servos
3. Baldor Mint Drives
4. ...others as well

Now if you want to make more exotic shapes like helical type cuts. Then use a multi-axis controller and you will need a encoder on your spindle. (or buy a CNC machine)

Cameron Anderson
Motion Control Specialist
Power/mation - St. Paul, MN