[jaru-eri]

My Taig Z-axis stepper loses step if I set up the speed to more than 20 inch/min, so maybe I need a stronger motor. I use Gecko 540 as driver and need to know which size of stepper motor I can use in order to prevent this.

[ThreeDJ16]

I have zero issues with my 386in/oz from Automation Direct and also a G540 with UC300ETH. And I'm running a 1 HP motor, R8 spindle with power draw bar.

Another thing to check is see if your Z gib is too tight.

[jaru-eri]

Another thing to check is see if your Z gib is too tight.

What do you mean about z gib? Is that the nut around the lead screw, or the clamps on the sides of the slide? I recently tighten it up in order to avoid backlash, so it could be the reason for this issue.

[ThreeDJ16]

What do you mean about z gib? Is that the nut around the lead screw, or the clamps on the sides of the slide? I recently tighten it up in order to avoid backlash, so it could be the reason for this issue.

Actually you should see a screw on the top and bottom of the Z saddle (right hand side) and that has the brass gib in between them. Best thing to do is rapid it back and forth and watch for hang ups. SInce you have made some changes, it could have affected the gib. You turn the top and bottom screws to push the gib around making it tighter or more loose. Youtube has some vids on how to do it. Just search Taig Mill there and a guy from Taig has vids on doing all that stuff.