Newbie- Hitachi Seiki 4NE-600 / Fanuc 6T. Spindle Overspeeding.

[swt-2009]

Hi there everyone, my name is Steven, I live just north of Perth Western Australia and I am new to CNC and new to the forum.

I have been trying to get my machine to work and have been battling it out on my own with the basic manuals provided and reading tips from existing posts.
I got to the point of entering a short program and getting it to run through to when the spindle was to start and a small cut was to be taken from the end of a bar.

With S1500 specified in the G50 settings and G97 with S600 where the spindle was to start it spun up to about the correct speed but no travel command was executed.

I tried moving the M03 down a line so it was just before the travel command hoping it may help.

It was definitely M03 and nothing else was changed.

Upon trying to run the program again it got to M03, fired up the spindle in reverse and revved to what I am certain was beyond the 3150rpm redline of the machine. (In M42)

Luckily the machine was smart enough to detect this and cut the power to the motor and lit up a motor alarm light on the control panel.
No alarm code was given and the red light could be reset by switching off the machine and re-powering it.

Tried this a couple more times to be sure and same result each time.

Came back later to try running spindle through MDI. M40 S100 M03, no worries, gave it S150 then S200 then back to S100. No worries at all.
Stopped it with an M05 and then tried an M04. Redlined it again, straight away, although only in low range this time.

Something wrong here. It would do this fine through MDI beforehand.

I do suspect that the speed commanded and the actual spindle speed had a variation of about 5%. e.g. M41 S1000 would read 950rpm on an expensive photo electric tacho.
The tacho needle on machine never really read correctly either.
These details may be important clues.

Any ideas or advice as to why it would start in reverse rotation with an M03 let alone rev way past the S1500 in the G50 settings would be appreciated.

Thanks for taking the time to read all this and if you have any tips for me please pass them on.
Steven.

[James L]

Was this a new machine or refurbished?

[swt-2009]

Hi James, it is a 1980 model, I brought it in a used but working order.

I had just read some words of wisdom so went out to write down and record all of the parameters. While looking I ran through the diagnosis pages and noticed some flashing bits in the data. It looks as though it is in pain with zero's and one's flashing wildly back and forth.

Could these flashing bits be indicating a problem?

Line numbers 0195, 0196, 0197, 0238, and 0239 had most of the eight bits per line flashing. Some flashing at a different rate to the others.

Lines 0800 and 0801 only have four bits. only the fourth bit is flashing on these lines.
Line 0801 also had a flashing negative sign before the four bits.

Does anyone know what all this could mean?

Steven.

[bugdog]

Hi

Sorry for the late reply have you checked the dry run switch
If the feed on the button is on zero the slides will not move in dry run.

Also the"program check" switch above.
Flick this up as it may be checking the prog when you press spindle start and the slides will not move.

Regards bugdog

[underthetire]

Run away=no tach signal from the motor IMO.