Question???? JUMPY AXIS

I have a Smithy 1240 Combined mill and right now the axis's are sporatically jerky on ALL 3 axis's and with every jump/jerk they lose a few thounsandths position, I am wondering what may be causing this and I have looked and cleaned every connection I could find to each motor and the board connections in the computer. It is funny that it is All 3 axis's though and seems to be the worst in one direction over the other.

Any thoughts on what this may be or are my drivers/computer burned out?

 

If I am running a program, it will run just fine however all of a sudden you will hear a stutter within the stepper motor axis once in a while but if I run the jogs and feeds slower it does better. basically every stutter lets just say I will lose .005 on position on that axis. I can't Video it right now due to a broken z axis ball screw.This happens on all axis's though so it seems like it may be in the drivers. Is there something that drives ALL 3 drivers that may be going bad? It used to always run just fine for years and all of a sudden started doing this. ??????Lightening??? I don't know. 

www.google.com/url?sa=t&source=web&rct=j...raln0Q0u3A5d6CvfC2SN

has it got the wrong lubricant on the slideways and ball screws.... how did you break a z axis ball screw?

worn out or broken?

More guesses: latency spikes and/or marginal step times ?

Run latency-histogram with the correct base and servo period settings and post a screenshot.

It is a smithy 1240 combined CNC and I am struggling to send Videos, I could e-mail them to you if it is acceptable just give me an address. I have been using Vactra 2 oil for years. The ball screw broke during homing the machine and you can move the head with extreme ease except when the motor jerks of course. Weird, I have been machining for 30 yrs and this has me ?? I believe it is something driving the stepper motors?? The spindle motor runs smooth as glass still and for the most part it is only 1 way on the axis motors.

Thanks
 

I did run the latency test these are the results. I ran it 3 times with similar results each time                                     
                                     Max Interval (ns).     Max Jitter (ns).    last interval (ns)
Servo thread (1.0ms)      1009663                     20109                  984976
Base thread (25.0us).          33233                     12686                    30183