TC-22-Tool Changer

[debco99]

Worked on a customers TC-22 last week and was getting an error from the drawbar during tool changes "Invalid Switch Condition".
This fault occurs after the Z axis has unclamped and is at the home position waiting for the carousel to rotate to the desired tool.

I noticed that when the fault occurs the drawbar releases and retracts although the I/O indicates it should be unclamped.

Relay CR4 is not on and should be.

I checked the switches, adjusted them, did the hokey pokey all of it and no luck.

I have went over this to the point I am suspecting the tool changer board I think it's called the LcTaulf anyone ever see this problem?

Thanks in advance

[MetalicGlow]

Originally Posted by debco99 Worked on a customers TC-22 last week and was getting an error from the drawbar during tool changes "Invalid Switch Condition". This fault occurs after the Z axis has unclamped and is at the home position waiting for the carousel to rotate to the desired tool. I noticed that when the fault occurs the drawbar releases and retracts although the I/O indicates it should be unclamped. Relay CR4 is not on and should be. I checked the switches, adjusted them, did the hokey pokey all of it and no luck. I have went over this to the point I am suspecting the tool changer board I think it's called the LcTaulf anyone ever see this problem? Thanks in advance

I had the same error on my TC-22. The machine had been sitting for a few weeks and was simply "stuck" in the wrong state. I took a wooden stick and and gave it a few taps and the error went away. My error happened while the carousel was actuated to the right and fully engaged with the spindle.

[machintek]

I have seen this many times. This alarm can occur if the tool changer forward/reverse or the drawbar clamped/unclamped switches are in the same state for a period of time.
Most repairs were switch related. They were out of adjustment.
I have seen a insufficient air supply (regulator pipe was clogged with scale and/or hose too small) cause the alarm. I watched the pressure drop and the drawbar come up working against the retention springs.
Broken spring washers in the drawbar causing drawbar to jam and not go all the way down.
Does it work with the button on the head?
Do you see an output to CR4 in the maintenance page?
Typically the solid state relays on the LCTLAUF go (short) and then the tool changer will not stop turning or has trouble going forward or reverse. If the solenoid is shorted it might take out one of these relays. Most relays have a resistance of 4 mega ohms across the 2 output pins. Anything less is usually a bad sign.
While there check that the arm on the motor is not loose and centered to the prox switches, the cam follower in the arm is not loose and the shock absorber is working.

George

[debco99]

Maybe one in every twenty times it will work.
The button on the head works fine and I checked the air pressure.
The relay for the drawbar (cr4 should stay in until the new tool is in position and the head comes back down.
Instead it picks up and drops out as the head is going home.

The air pot is on a three pont suspension and has a collar that is on one side of a thrust ring. How normal is it for this to cock when the drawbar is unlocking?

It appears it has to cock because of the way it uses that collar on one side only.

Thanks for the suggestions fellows.

Dave

[debco99]

How much pressure drop should I see expect to see on the gauge when the drawbar is unlocked ? The pressue is set at 80 psi but it seems to drop 30 psi or more when the drawbar is activated.

What is the normal life of the seals in actuator?

If the pressure drops enough to allow the retention springs tp push back I should see this if I held the pushbutton on the head down for a period of time.

Thanks again for the advice.

db

[debco99]

George, on the maint.display (outputs) it shows the output to cr4 as on but of course the relay is off.
This is what made me thing the t/c board was possibly bad, but I have doubts.Be nice to have one to try.
When the control goes into an alarm this page only shows the last condition of the I/O and will not allow any updates until the alarm is cleared.

I will be returning later today and will take another look.

Thanks

[machintek]

Make sure relay is good. Remove the diode across it for test purposes. I have had more than one diode short and give me fits. Wait a second. I believe that I am getting a ice cube relay confused with the relays on the LCTLAUF. Disable the air blow. Just remove the connector on the solenoid. This is what consumes all the air. Again only for test purposes.
You can always solder a wire onto the relay coil from the bottom of the LCTLAUF and put a meter onto it to see if the LCTLAUF is putting out a signal to the relay.

George

[debco99]

George, looking at the print the relay on the LcTlauf drives the unclamp relay which is CR4 JP9-3A & JP9-1A and this in turn drives relay CR4 with 115 vac the relay gas a rc network on it.

The air blow is the same (different out from board) and then drives CR5

This picks up Sol 4 & 5

Kinda baffles me why they used a relay on the board to drive an ice cube unless they wanted to ensure it was isolated.

Thanks for the response, I am going to pull CR5 and try it without an airblow.

[machintek]

Check for voltage at the relays and a good ground. And yes remove the diodes or RC networks. I have to find a print.

George