Anilam Vertical mill crash

Just for the record and because there will be doubters out there.....

Anilam 3000 on a 5hp Topwell mill.

Ran a simple program to cut a gear, 25 teeth and only had a single point tool for the job.
Setup dividing head and let program cut each tooth space with 8 cuts increasing Y depth each pass.
Program ends, index to next tooth space manually and start program again.
This is slow cutting, 250 rpm, 2"/min feed rate so I was doing other things while program ran.
Cut 23 tooth spaces with perfect results, then disaster, the Y axis decided on its own to move to .9 instead of .475, not sure how far it would have gone in Y axis as that was where the machine shut down- too much lag or some such error message on the screen.

Bent the boring bar and pushed the work out of the chuck, damaged the gear and pushed the tailstock out of position.
I was not a happy camper. I did not know that this kind of thing could even happen. I get that you can make a program mistake and have a crash, didn't know the machine can decide to have a bad day and crash.

How do I trust it ever again?

Photo shows setup and results at about #15 tooth space.

I have heard older CNC machines can have a processing lag and drop a line of code once in a blue moon. Or read the same line twice or some such.

Is the machine old? Literally anything like a surge or power fluctuation you didn't even notice could cause it to glitch for just a second.

If it is old I would check the caps and other electronics and make sure nothing is looking swollen or like it has a brown stain. Will work for quite a while but get weird on occasion. Bad memory can cause that kind of thing too.

Old servo amplifiers are not always that great at shutting down quickly if there's a fault, and old controls are not that great at responding quickly if an axis takes off.

Did the machine start up again and work normally after this happened? I ask because the only time I've seen something like this happen was when one of the power diodes in the H-bridge shorted out and the axis ran away at full speed until the control noticed and shut it down. If you had something similar happen then it would either not start up, or just run away for a short distance ever time you try and enable the servos.

Jax,
In CNC terms it is old but not ancient, 1998 machine, control updated to the 3000 series about 10 years ago from the 1000 series.
I will have a look inside the box. A power surge is also a possibility. When my 20hp comp comes on the lights flicker for a second.

greg,
the machine started up fine after the “ incident” but I have not done a lot with it since.
Luckily there doesn’t seem like any damage to the spindle or machine.

What does it use for the Z encoder?

Dan,
I have no idea?
I just got the machine in December and I am learning how to program and run it.
I have the manuals for it, what am I looking for exactly?

M. Moore said:

A power surge is also a possibility. When my 20hp comp comes on the lights flicker for a second.

Click to expand...

Think about setting up a "soft start" for your compressor. If it reduces the current surge it might be a general help, even if not the solution you need for the mill.

Thanks for the tip Milland,
I will have to inquire about a soft start system in the electrical forum as I know very little about them. I also wonder if there is a way to isolate or insulate the mill wiring from any surges?