[cjchands]

-->Completed setup minimill-- X,Y ok.. BUT Z-AXIS has problem--- Need advice!!!

Hello guys,
I am using hobbycnc 200oz-in 3 axis drives/motor and I completed mounting 3axis with the mini mill show in the picture. I am running the software with MACH3 and motion seems fine on X-Y axis.

One problem!!! The z-axis when move down seems ok, but when it move up SOMETIMES it lag few steps before it pulling the spindle head pull up.
I believe the reason might have to do with
1. Motor 200oz-in is not powerful enough to pull up the spindle head?
2. Too much friction between coupling at the contact with the motor mount.

This is the first machine I built, so I assume that Mach3 and Driver should be ok and the problem lies mainly on MECHANIC!!!!!

Any advice from experience people?
Thank you
Jeff

[pastera]

The stock screw has a LOT of backlash.
Change out for an acme screw - you may be able to use the X-axis lead screw (available from Little Machine Shop)
Counter weight the head to offset weight.

Aaron

[drwc]

Thats characteristic of backlash, happens both ways but always more noticable on the way up. Will badly affect your accuracy in CNC environment.