HELP! Gross positioning error

[crazeekev]

Hi,

On start up the x axis keeps tripping out on the software limit and coming up with 'Gross positioning error a'.
I had previously entered an incorrect value in MP0 in the parameters and have since corrected it. Any ideas anyone?

Machine is an Interact 1 Mk2.

Cheers

[gus]

Do us a favor, stick to a single thread so we don't have to read 3 to figure out what you are talking about. Either that or tell us EXACTLY what is going on. Was this while homing? You are back to tach wires or motor wires or a parameter involving traverse direction.


Oh did I mention, download your parameters before you mess with them [again]

[crazeekev]

Hey sorry dude!

I did this as a separate thread as it's not related to the Y axis motor that I was working on. This problem is on the x axis.
I have got the parameters written down, I just didn't have access to them at the time of working on the machine. I now have the same value of 5000 in MP0 parameter that it originally was.
When referencing on start up it comes up with 'Gross positioning error a' when finding the x axis limits. Surely if it now has the correct value in the parameter it should be fine?

The Y axis motor wouldn't have any effect on x axis operation would it?

Let me know if you need any more info.

Cheers

[machintek]

Conflicting data.
Does the X axis home correctly or does it go to the end of travel and hit the overtravel switch (hard limit).
Where are your software limits set? They have to be set correctly to allow full travel after homing the machine.

George

[gus]

As a wild screaming guess I would say it travels to the trip dog and when it reverses and tries to close the position loop it runs away. counting direction set backward or bad wiring

we really need FULL background on the machine.

And yes, it is relevant that 2 axis are misbehaving

[crazeekev]

Ok guys, heres the story from the start.

The Y axis motor was juddery due to on of the magnets falling off the casing. I was initially going to swap the motor for a spare so had disconnected the wiring to the motor. I then decided to bond the magnet back to the original casing and stick with the motor on the machine. I reconnected the wiring back but had evidently connected the 2 wires to the tacho the wrong way round as the motor was in full speed traverse all the time!
I swapped these 2 wires round and the motor operated at normal speed.

On referencing the machine the y axis seems to have lost its parameters so I hand wound the bed on the y axis belt to the reference dog and then carried on to the x axis which at the time was operating fine. So I was now out of referencing sequence and put the code in to get the parameters up to sort out the Y axis limits. In a moment of brain fade! I started to change the MP0 value! It turns out this is X axis traverse speed and at the time I didn't have my parameters sheet with me so I went with a value of 4000.

Turned machine off and on again and went through the referening process again. This time when it got the X axis it trippped at what I assume is the reference dog or software limit (the same point that it always goes to when referencing), and came up with 'Gross positoning error a'.

I guessed it was to do with the parameter value I put on so I checked the sheet and one of the guys on here confirmed that the value is 5000. I put this value in but it still comes up with gross positioning error a when referencing!

Its frustrating as I guess it willl be something pretty obvious!

Sorry for the long winded reply but thats the full story.

Thanks guys and really appreciate any help.


Kev

[gus]

I would not think that a small value difference would give you an instant GPE. It usually gets worse as you approach rapid. With the speed override knob turned low you should be able to move the machine slowly with almost any value in there. Are you sure you did not change some other parameter accidentally? Go through your list and see if anything looks wrong.