Long title, says it all basically so I was after a bit of advise.
My mill is a Denford Easymill with 3.5 amp steppers on all axis, this weekend while machining some parts the Z started to loose steps while retracting on rapid moves in fact it just stopped moving sometimes, just like it was getting stuck or something.
Anyway I tried the axis by hand and it felt OK and moved smoothly, I then lowered the rapids down from 1m/min to 500mm/min.
The same happened but I noticed that the stepper seems to go through a funny patch like it's vibrating or something, could this be harmonics?, it's when it's making this noise that it stops being able to drive the axis.
X and Y have no problems with the same 2:1 ratio and 5mm pitch ball screws but they are dealing with the weight of the whole table however they weren't doing anywere like the same amount of work as the Z axis.
The workshop was really hot this weekend so I wondered if the driver was overheating and not being able to output enough power to the stepper so when I get chance I'm going to try it one evening when it's cooler. (unfortunately that looks like tomorrow)
I'm using Routout CNC 10amp drivers and a 37V 20amp power supply but no cooling fan in the case.
So if anyones got any ideas please let me know.
Thanks
Steve