Turret will not clam or unclamp tools!!!

Hi All,
I have a Hitachi Seiki Hitec Turn 25M that we do not use often. I used it for the first time in a couple of months last week. Everything seemed to be ok with it until this AM. I was in the process of setting up for a new job when I realized that I could not unclamp the tools to replace with new tools of new setup.
Everything seems to be working fine with cnc, the only problem is that I just can not change tools. There are no ALARMS letting me know of any issues either.
Please help!!!

Gamy R.

Gamy,

give me a little more detail. Whats the control and what style of holders are they?

John

Hi John,
Control is Seicos (LMulti) and the tool holders are KV40. What appears to be happening is that the cylinder that locate behind the turret is not engaging on to the back of the tool holder thus not releasing. Today what I hear is a low buzzing sound coming out from the turret or back of the turret rather then it alarms out with a 280.

Thanks,
Gamy

Gamy,
so the cylinder is not moving at all. It will be a cylinder and a pin that work in conjuction and are sequenced together. If they are not moving at all we need to work backwards. How are the rest of your hydraulic systems?

John

Hi John,
All of the other hydraulics are operating properly.

Gamy

Gamy,
Is the clamp/unclamp cylinder moving at al?
John

Hi John,
No the cylinder is not moving at all. These also seems to be a beeping noise coming our from behind the turret... I have scheduled a cnc tech to come by next week but any input helps.


Thanks,
Gamy

Gamy, if the other hydraulics are working but the piston doesn't move, its either mechanically stuck (unlikely) or the solenoid/SSR is stuck which is the probable case. If you can look in the diagnostics and watch the bits for the clam and unclamp solid state relays while you push the button you can figure out where the issue is. It can either be the SSR is changing but one side is stuck, or the solenoid is fried and non-functional. Let me know how it turns out

John

John, Is there a # where my tech can reach you at?
Gamy R

John,
We ckd clamp/unclamp solenoids. Resistance equals 24 ohms on both, measuring same as on all other solenoids.

The signal LEDs however do not indicate that either solenoids are on.

Shortly after going on standby we get alarm (approx after 1 minute).

We get alarm on top left 280: machine not ready
Bottom Left we get message
AL-20 NC Servo Alarm

If it all possible my tech would like to contact you. Is there a time and # where he can reach you?

Thanks,
Gamy R.

One more thing,,, in the diagnostics the bits do not change back and forth indicating that one or the other have even actuated...

Gamy, the fact that it wont change bits is a good starting point. The next place to look is for the clamp/unclamp push button bits. Also when you were checking the solenoids, did you check for power. Often the lights go bad or fry, but the unit itself is OK. Let me know, I PM'd you my number

John

I apologize for jumping on this thread. First I thought I had the same problem and changed the solenoid. However it was not the problem. Maybe someone can help me. My tools are not clamping tight. I can clamp a tool holder in, but I can wiggle it by hand. It's not much, but enough to screw me up. The cylinder is working. This is happening in all tool positions, although some are tighter than others. I tried different holders, but the problem continues. Without a tool holder and the KV40 clamped, I can move the three balls, which I assume I shouldn't be able to. My turret is radially aligned within .001. We used this job to run production for the last couple years with only 2 tools. Even they are loose once I unclamped and clamped back up. Can anyone help me with this problem?
Thanks in advance

Hello,
that has to do with the cylinder below the turret. The clamping mechanism is not as simple as it seems. It is actually a timed actuation, and if it is too fast or too slow, the clamping balls do not fall into place in the groove in time, and get stuck, leading to loose clamping. What you have to do is take the cylinder off, take it apart completely and clean it, lightly clean off rust or surface imperfections. Buy new seals if you can and put it back together and hope for the best. This will fix the problem 99% of the time.

John

Thanks John,
Are you talking about the cylinder with the pistons that push on the tool clamping device? If so, any idea how to get to this? The clamping does seem simple, but I guess I am wrong.
Thanks Again

Steve

Another thing I noticed. I removed the cover on the side of the turret. When I clamp and unclamp the hoses going to the cylinder move somewhat "violently". I compared this to the spindle and it is much different. I don't know if this means anything.

Thanks
Steve

Steve,

you could try to bleed the system; there might be some air in there, but normally that gets filtered out, unless your reservoir is really low and constantly bubbling and making air.

John

Good Morning John,
The hydraulics check out. One hose is pressurized while the other has none and vice versa. John, Do you think I should pull the cylinder and check it out, and clean it? Is there a dimension form the face of the turret to the cylinder in the unclamp position I can check? Maybe I am looking at this wrong, but it is tough to find someone that knows about this? I need to try to figure this out.

Thanks for any more help you can provide.

Hello,

got your PM and replied. Take a look. Its the cylinder, Im pretty sure

hello,
i am using puma230MS fanuc 18i-t control, few days before my hydraulic was not getting ON so i used to unplugged the solenoid valve near to hydraulic tank and it used to get ON , but since yesterday i did the same hydraulic also get ON but when i reference the machine turret did not move , i again unplugged the solenoid valve and tried doing but since that time machine after x, z its not coming back to main spindle mode . please help me out