[SteveCNC1969]

Here's the issue I'm having. Just purchased a CNC mill, one of those Rongfu conversion setups. Was done REALLY professionally with Gecko drives and servo motors. Ok here's the deal, it came with Mach2 and was working fine although for some strange reason Mach2 wouldn't function properly with my g-codes that called for incremental positioning. So what to do, upgrade to Mach3 of course.
So Mach3 works perfectly ..... except ..... when I move my X and Y axis they now hesitate for fraction of a second when they initially start to move. BUT (and yes there is always a but) if I stop the motor and start again in the same direction it doesn't hesitate on startup, BUT if I switch directions the motor will hesitate again for the split second when it starts to move in the new direction.
The motor velocity/acceleration setting in Mach2 were accel 3.99 velocity 1.001 and moved the motors at about 30ipm. But to get the motors to move at the same speed with Mach3 I had to set accel at 40 and velocity at 10. What am I missing here?
You can see the steppers 'hesitating' here at [nomedia="http://www.youtube.com/watch?v=JKvwl2XR36o"]YouTube- VIDEO0006.3gp[/nomedia]
Nothing mechanically is stuck, everything moves smooth and easy manually and it does work perfectly with Mach2, just hesitating with Mach3
Any suggestions are GREATLY appreciated.
Steve

[cmacclel]

Bump......no one??

[neilw20]

Do you have backlash compensation enabled?

If so, whenever there is a change in direction on an axis, the other axis have to wait while the one changing direction catches up.

or

Do you have the logic edge for the step signal active low instead of active high, or vice-versa?

Look at the specs on the driver, to ensure that when the direction signal changes, the step signal is in the correct state.