[Jim Wilson]

I have a (1993, I think) Conquest T51 turning center with a Fanuc 18T control. It won't zero return.

Honestly, the problem could be operator error -- uh, that would be me . This is the first power-up since I got the machine, and I am not very familiar with it. Here's what I think is pertinent:

The control powers up fine with no unusual messages or alarms. The coolant door check works, and after emergency off reset, hydraulic pressure comes up and all alarms clear.

(By the way, during control power-up, the Jog Mode indicator on the MDI panel flashes briefly, but it doesn't stay on. Is this right? I thought the control was supposed to come up in Jog Mode.)

I use (-Z) and then (-X) to move the turret approximately 1 inch in each axis. Works fine. Then I press (+Z) to initiate a zero return, and nothing happens. (+X), same thing.

I tried pressing the Zero Return button first, but that didn't help. I also tried pressing the Jog Mode button; again, no change. However, the Jog Mode indicator does not light. Does this indicate a problem? The indicator itself must be ok, because it flashes on during power up.

The bottom line is that (-Z) and (-X) move the turret, but (+Z) and (+X) do not. However, if I hold the emergency reset button down, then (+Z) and (+X) _DO_ move the turret. This makes me suspect that holding the emergency reset button overrides some inhibiting condition(s) for (+Z) and (+X) motion. But there are no overtravel or other alarms or operator messages indicating something is amiss.

Am I looking in the wrong spot? Skipping a step? Do you have any ideas or suggestions for me to try?

Thanks!!

Jim

[Jim Wilson]

In case anyone's interested, I got a good answer from Ox over at PracticalMachinist. Thought I'd pass it along here, in case someone else makes the same mistake I did. Cheers -- Jim.

What follows is a copy of the message originally posted by Ox on practicalmachinist.com:



Sounds like everything is werking right - 'cept'n the operator.

Bear with me as I have a sub spindle machine and I am assuming by the sounds of it that you have a tailstock machine.

The second thing that you need to doo (stick with me here...) is to move the Z- an undesignated amount - but lets say and inch or so. This amount needs to put the turret and tooling clear of the tailstock, so keep going as needed to clear. Even if the Z is already clear - it STILL needs to move an inch or so anyhow.

Third is to hold the X- down untill it stops ON IT'S OWN at 2.5" [or 1.25" of travel].

Fourth is to key the X+ button and the axis should move to home (prox X15") by itself. Then key the Z+ button and it should doo the same.

If you get an overtravel alarm - just power down and try again. Either power off at the wall (back of machine) or hold the "cancel" and "P" keys down together during power-up to clear alarms.

If you still get an overtravel alarm then you would likely have a limit switch that is bad. (future reference.)

NOW - the FIRST thing that you need to doo is to make sure that you have enough room to move the X and Z in the direction the amounts that I said. As you have already found out - you will need to hold down the E-stop Reset down to move these directions at this time.

If your axis "home" and your not in auto mode automatically - you may have a "home turret" alarm. For this you need to make sure the turret is clear of obstructions and hold down the "Home" key (or whatever it is - just to the lower left of the E-stop button) and the "turret index" buttons at the same time and watch'er fly! You will then need to re-home the slides even if they were already homed.

I assume this should be the process - but I have an extree axis that you don't have, so there could be something going on with the tailstock in there - but I doubt it. ????

Think Snow Eh!
Ox