I work in a company that owns some HURCO machines. One is a HURCO VMX 24S. After a "tech" guy came to fix some issues on the machine, we started to have some issues on axis z
So let me describe what is happening:
-on power up everything is ok
when i'm trying to calibrate axis, x is ok, y is ok, but z it goes to 0.006 and an error message is displayed "Axis limit switches +Z" and on the bottom of the screen " Following error on axis z"
-if i reset servos and calibrate again, z it goes to 0.012 and then to 0.018 and so on
- i can manually jog x and y axis, but not z
-spindle is turning ok
Does anyone know ho to try and fix this?
I have attached a picture of the screen.
PS: i'm not a very tech-know-how guy so please try to explain as clear as possible.
Your machine is much newer than the machines I am familiar with.
Axis following error means the machine did not move as far as was expected, or moved too far.
Usually the error is caused by mechanical looseness in the drivetrain for that axis. There are couplers in the Z axis between the motor's driveshaft and the ballscrew. These can loosen up over time. Check they are tight.
The problem can also be cuased by trouble with the encoder. I don't know if the encoder is on the motor or on the machine itself. If the encoder is loose you can get these problems.
The problem can also be cuased by servo tuning. I cannot help with this. I am not familiar with the servos used on newer machines.
Thank you for your time and advice. I will try and look at the axes limit switches, and then try to see if the encoder settings and functioning is ok. At the same time i have contacted Hurco support to get some hints from them to.
I don't think is a mechanical fault, but i will not rule out that possibility yet.
Thank you again.
If the encoder is loose on the motor shaft you can get the axis following error. If the motor is loose where its attached to the ballscrew you can get an axis following error.
I don't know what type motors you have. If the encoder is attached to the motor it's under the motor's end cap. The Z axis motor is easy to get to if you can get up that high, it's sticking out of the top of the machine.
I would first check that the motor is tightly connected to the ballscrew.
Then check the motor is tightly connected to the encoder.
I believe the newer machines are direct drive from the motor to the ballscrew. The coupling is known to loosen up and cause this problem.
I have checked and cleaned z axis limit switch. It runs fine, but on current z axis position the z+ limit switch is pressed. so i removed the axis limit switch and tried to manually jog z axis, but no movement at all. So what to do next?
What happens when you jog the Z axis in the opposite direction of the limit switch (if the +Z limit switch is on you can still jog in the -Z direction).
Does the Z motor turn?
Does the Z position on the screen change?
Do you get the Z axis following error?
Do you get a different error?
I cannot move z axis in any direction, even if i removed from location the limit switch.
I get after calibration a " following axis error" , the z position on the screen changes with 0.006 MM
The z axis amp isnot showing bb on start-up i get a P not after power-up.If i use mode/set button, i don't get a run mode, only P not, fn 000, pn 000 and un 000. The amp is a yaskawa sgdh 30 AE
When you calibrate the machine does the Z move? Can you jog Z before you calibrate? You should be able to jog Z with the machine uncalibrated - actually you should be able to jog all the axes with the machine uncalibrated. Even if a limit switch is active you should be able to jog away from it. So, if the +Z limit switch is active you should be able to jog -Z.
If Z never moves even when you jog it manually, you've got a problem with the servo amp, the servo motor, the encoder, or the wiring. The reason for the following error is because the control tells the axis to move and it does not.
If Z moves when you calibrate, then the Axis Following Error occurs afterwards there's almost certainly something wrong with the encoder.
So, please tell us if you can jog Z before calibrating, and if Z moves automatically when calibrating.
Are you getting a PoT and noT on the drive display? Positive over travel and Negative overtravel is what it means. If so it could be a bad limit switch, but both plungers at the same time is odd. Is there a limit switch indicator always on your screen in the manual page just under the axis position readouts? Z+ and or Z-.
Thank you for your posts. The machine is now working. Yesterday they have called a technician to fix the machine and he has fixed it. I was not at work at that time, but from what i heard from my colleagues, the z axis was mechanical blocked,he removed the problem, and he modified some machine parameters to fix z axis travel. Today we will test the machine. I will try and find out more about what that guy did and post the procedure, if i can. Thank you for support.