[Help] Z axis motor stuttering

I've been having trouble getting my Z axis motors to work correctly. I'm using the mega 2560/ramps 1.4 combo and Marlin firmware. The problem is when I go to set the steps per mm for the Z axis to the proper number(2560) it stutters horribly even under no load when I tell it to move in repetier. When set to a low steps per mm (400) it appears to work fine other than having incorrect distance movement. Any suggestions on what could be causing this?

Feedrate too high in Marlin?

#define DEFAULT_MAX_FEEDRATE {500, 500, 2, 25}

If it's 5 rather than 2 try change it, compile/upload

If it's not that, check motor pairs with a multi-meter

Steve

---

My updated Instructable on our Prusa i3 Build
[www.instructables.com]

That appears to have helped greatly. Thank you.

I am having a similar issue with my Z axis. The default MAX setting in Arduino was 180..... when I jog it 1mm, it maxes out at 18. Where can I change that setting?