[foolmaker]

Hi-there

I keep getting the error msg

GROSS POSITIONING ERROR Z C

followed by the rset of the sceen being filled with lists of letters and numbers, are these parmeters?
The machine runs fine for a while until the error msg occors then I have to redatum the machine which is most anoying!!!
PLEASE HELP!!!

[gus]

You need to explain exactly what you were doing.

Most likely it was a rapid in z and the z needs the servo tweeked or perhaps jsut slowed down if it is just old and balky

[foolmaker]

It only seams to happen when rapiding down or up in Z axis at 100%. Ive been told I can slow this down by changing the parametrers but Im not sure how to excess them, or which ones to change! Can you help???

[foolmaker]

Ive managed 2 change the parameters now slowing the rapaid speed by 1000 but it still comes up with the error msg.... Do you think the z axis motor is on its way out!?

[A.A]

Hello Everyone,

I have a more interesting "GROSS POSITIONING ERROR A" Problem. I switched ON my machine after more than one year of use .When i was referencing the machine axis it referenced the Z axis normally and when i tried to reference the Y axis it came up with the "GROSS POSITIONING ERROR A"..................................

Now the interesting thing is that after turning ON and OFF the machine many times the " Y axis Reference " line on the CRT became highlighted and the Y axis motor started to rotate in opposite direction i.e. the table started to move away from Y reference and without detecting limits.

Is there any one who faced such a problem ever ???????? for TNC 151

Regards,
A.A

[gridley51]

Here`s my reply to your problem in the first thread you had started.

"I still think the drive was ok and you have been done.The reason for this is that to stop the spindle the control turns the analogue 0-10v to 0Volts and removes the enable from the drive when the spindle reaches zero speed as set by a parameter in the drive.It`s a bit more involved than that but that`s the basics.The drive does not know,recognise or care what code you put in to the cnc control.I could run that spindle up and down,forward,reverse,stop.start with a couple of switches,a pot and an AA battery without a cnc control being there.
Gross positioning error is the most common error most Bridgeport owners see and is applicable to Heidenhain.The letter after it determines where it came from and this is explained in the manuals which you can download for free from Heidenhain.com
It basically means that the axis is not in the position the control expects it to be.This can be a lot of things which are well documented on the Bridgeport forum here and a search will get you plenty info.
As a quick get you going,if you know how to change the parameters you can cut down the rapid traverse speed for that axis a bit and it might get rid of that alarm until the fault worsens.But then the fault is easier to find.
Mark.

[machintek]

The usual reason for a axis going in the opposite direction is that the switch is in the wrong state. The machine is still trying to come off it.
That is what you check first. Then worry about the rest.

George

[gus]

re:foolmaker

you need to readjust the servo tach setting after changing the max rapid setting. If you don't you will have made it worse