Mazak QTN100 Chuck not Actuating

Mazak Quick Turn Nexus 100, about 10years old. 640t control.

Pressing down on the foot pedal is not actuating the chuck. After a few pushes of the pedal, the chuck does eventually open.

Its a new chuck, cleaned and lubed.
Tried actuating with M code, but chuck M codes not an installed option on that machine

Im thinking its a bypass valve in the hydraulic system. Coworker thinks the pedal switch might be the issue. I hear it 'try' to actuate when the pedal is pressed.

Internet search said the actuating solenoid might be the issue. But that machine asked about was a 1984 QT15. Were they built similar?

Im not familiar with insides of these machines at all.

Suggestions?
Thanks

You are on the right path,

Check foot pedal for good electrical connection , they get bumped around a lot and may have broken wire,

Then on to the solenoid ,

Then to valve,

Sounds like one of those,

Good luck , ...........

Ok cool.

Well...i know where the pedal is , any idea where they hide that solenoid? Ive got the manuals at work and ill check it when i can, just figured id ask.

Smrtman5 said:

I hear it 'try' to actuate when the pedal is pressed.

After a few pushes of the pedal, the chuck does eventually open.

Click to expand...

Assuming no mechanical or electrical issues going on...

How fast are you pushing the pedal? Not sure about the newer machines, but the older Mazaks need a good half second press on the pedal to open the chuck, meaning step on pedal and keep it depressed until chuck opens. Quickly tapping the pedal with your toe does not work. My older Mazak will make a clicking sound like 'something' is happening if you just just tap on the pedal too.

Years ago, I had a finished part in the chuck and someone unfamiliar with the Mazak needed to remove the part following day. He could not get the part out of the chuck no matter how hard he tried. I came in and he said I need you to take the part out of the chuck, but machine is stuck. Machine is making a clicking sound when I push on the pedal but nothing works. He said he tried to get the part out for 15 minutes and gave up.

I walked up, stepped on the pedal and handed him the part and said what's the problem? He was like nevermind.

I havnt had the chance to dive into the machine yet. We are running a hot job and dont have time to tinker around. For the record, the issue seems to be better when we run the machine continuously. Its about a 2.5min cycle time.

Maybe that bit of information can help point me in the right direction when i do have time to dig around in the machine?

So its an intermittent problem?

Obvious question, but is the chucking pressure high enough?

Does the problem occur when the machine has been running for a few hours and warmed up, or just when cold? I encountered a similar thing a few years ago - turned out the hydraulic oil had deteriorated to the consistency of treacle. Try draining the hydraulic tank and lines and refill with fresh oil?

The problem seemed to come all of a sudden. We ran one job with no issues, then changed over the setup to the new job, which probably took an hour or so. We had just set up the job and werent sure we would be able to run it due to the chuck issue. After the operator settled in, he says the problem only happens if he walks away for a few minutes more than the cycle time (2.5min).

The hydraulic fluid probably hasnt been changed in ages...but the chuck pressure is at 200psi.

A little update...we finished the hot job, and setup for another job, with a 3 jaw chuck. The previous job used a brand new 2 jaw. The three jaw works fine. I guess its time to take a look at that new chuck...