"Gross Postioning Error A" Doing M03 on Bridgeport Interact Series 1 Mk2

[MeTri]

Hi Again,

I wish I wasn't always posting with problems... Yesterday I couldn't get past the inital checks, but today I was in manual mode and setting up a small test job. I was able to move the table back and forth and align my work with an indicator then I wanted to start the spindle. It took a while to find out how to do that. Well so I did a Tool Call and entered the spindle speed, then entered that, then hit stop so I could enter an M command. I put in M03. Then a star started flashing on the screen on the left hand side about half way down. I hit the green button and POOF! "Grooss Positioning Error A". At this point I'm baffled. So I look in the books and don't see how positioning relates to turning on the spindle. The book says it relates to param 57 and 174 (I think) and I didn't try changing the values as I don't quite understand them. I have taken courses in control theory, I do understand in general what PID controllers are and the different K's etc. but I don't understand how 57 or 174 would be tripped by an M03 command. My machine is capable of a 4th axis but it's not enabled. I have attached a copy of my parameters in case that helps. Any advice would be very much appreciated. I felt so close to actually cutting metal today... It was a bit of a let down, so I spent the day on the lathe

Thanks

Brian

[machintek]

I wonder if you have true 3 phase power. Usually very strange things happen with a high current draw that cannot be satisfied.
Do you have the contraves or KTK spindle drive?

George

[MeTri]

I have the KTK spindle drive.

Now as for 3 phase power, I checked the voltages between all the leads and it's all 600V (between 605 and 608 on each leg).

Now as for the correct phase being on each, I just don't know how to tell. The colours match up on the wires coming in, but not sure that means much.

The building has many 3 phase devices that are all working fine, so the wrong phase to the wrong leg, I could beleive, but the power is certainly true 3 phase. The machine also was connected to 600V before, that's the Canadian standard for 3 phase. The high current draw should be ok. It has it's own 30A line direct from the panel.....

Hmm....

[machintek]

I do not believe the spindle drive is phase sensitive. The cooling fan motor for the spindle drive motor IS phase sensitive. I had a customer at a steel mill where unknown to him the power was switched to the machine somewhere in the plant and the fan fought against the natural chimney of the spindle motor which would give a temperature alarm.
By the way there are LED on the top board of the spindle drive that indicate a fault. look at those. Also make sure the LED is lit on the MCT1 board. the failure of this board is the most common problem with the KTK drive.

George

[MeTri]

The fan seems to be running fine. i will check the LED status. Hmm, I'll go for a drive and check. Back in an hour and a half. I can't wait until tomorrow

Brian

[MeTri]

It's been a bit more than an hour and a half, but I did get the spindle going... sort of.

So conclusively the KTK spindle drive is very sensitive to the order of the phases. It needs L1, L2 connected to E1, E2 and then L3.

I checked the LED's on the spindle driver board and OK was lit. As soon as I hit the yellow power enable button, Ins Trip LED went on and the OK went off. The KTK manual says this is due to the order of the phases being wrong. I switched the order and try again. The spindle came on! I was very very pleased. I then tried edge finding and setting a zero... then the spindle started making a funny sound. Not serious going to blow up funny, but funny none the less (this may in fact be due to the phases not being correct, well partially correct and with 3 wires, that's 6 possibilities, and only 1 is correct, but 3 will partially work I think.) Anyway the manual says what will go wrong if they are only partially correct. Before I could test that, a big flash and spark comes from the connection from the power to the control box. Damn! someone used BX cable and the wire was nicked. When I was looking at the spindle it must have moved and shorted out. A fuse blew and I didn't have another.

I did shut off the power as soon as I saw the spark. Since the spark blew a fuse and the spindle can't run missing a phase I assume it stopped before I turned off the power, but I wasn't watching, just having a local panic attack. So my question is now, why is there a sign next to the main contactor saying "Do not turn off until the spindle is stopped?". I could guess it's because the brake comes on when the power is off and that would be bad if the spindle was going... this just occured to me now. Any thoughts?

Thanks again, I'm back to... maybe... not having a problem and my spindle ran, the table and quill move.

My quill does hunt and peck a bit when moved. A little oscillation before coming to a stop, some places it's better than others. I'll have to check the PID values? One thing at a time.

Brian