Axis Calibration

[davidshearer]

I have a Tree Journeyman 310 Mill with a Dynapath 20 Control. The Z axis moves a greater distance that the controller instructs it to (programed or jog). How is this properly corrected? Is it a matter of calibrating the control, the servo driver, what? I currently use the scale function, but it seems a bit around about and isn't all that accurate.

[underthetire]

By how much ? Are we talking thousandths or inches?

[davidshearer]

On the Z axis a 0.100" jog results in a 0.127" move. That's considerable. Sound like a messed up parameter setting?

[elnerdo]

does the z move .127 in both the up and down directions?

the z-axis has a smaller diameter motor pulley (at least on my machine) so a previous owner may have replaced the z-motor, with an x or y motor and not bothered to change the pulley.

changing your user unit parameter for the z should fix your problem. i think i have an extra z-pulley if you want to replace yours.

[davidshearer]

Elnerdo: Yes, the error is in both directions. The hardware is all original. But thanks for the offer of a pulley. After talking with Al Strelbicki at Parts & Smarts, the answer is yes, it's a parameter setting thing and help is on the way.
By way of acknowledgment, Al and his crew really seem to know their stuff when it comes to Dynapath and Tree. I highly recommend them! They aren't free, or cheap, but well worth every dollar spent.

[Toolbit]

Check the z-axis ball screw mounting under the pulley. The nut that preloads the bearing sometimes works loose.

[M.BAVYA]

first u have to check the ratio of pulleys what u put the parameter that is correct or not otherwise we r having laser instrument for checking linear measurement and u should check ballscrew assembly any bearing preloading or any un tightened screws

[underthetire]

Before you tear stuff apart, make sure scaling is set to 1:1. Sounds like a scaling issue to me.