[ZR Machine]

My VF-4 has a pause of about 8 seconds everytime it changes a tool. The head lifts off the old tool, changer rotates then the head drops on to the new tool then pauses for 8-10 seconds then the tool changer moves back like it should. Any Ideas??? Thanks Dan

[Geof]

The tool release is an air cylinder and piston that pushes down and releases the tool during a tool change. There are limit switches at each end of the piston travel. Possibly the vent outlet on the solenoid valve controlling this air cylinder is blocked. This would mean that after the head has dropped and the controller has turned off the solenoid valve it takes a while for the air to vent and allow the piston to return. The controller is just waiting for the signal from the limit switch telling it the piston is retracted and the tool is clamped.

This kind of blockage can occur if you have water and/or oil in your air supply.

[ZR Machine]

Thanks Geof, Where is this vent located so I can see if it's blocked??

[Geof]

Somewhere up near the top of the spindle. You will probably have to take off the big cover.

[wms]

I'm with Geof..but before you go tearing it to it..

Try spraying a ton of WD40 into the two air lines that go to the head stock..and then cycling the tool release a bunch of times..to work the WD40 up there..it will sometimes un stick the piston and solenoid.

The two air lines, (one small and one bigger) are located next to the coolant hose from the pump to the head..and they just unplug from the regulators with a push pull connector..

[Geof]

Yeah... I guess I should have said that. Now let's see if WD40 is not enough is there anyway to use duct tape?

[wms]

Geof,
I'd have to call a specialist for that..as I'm not certified to use Duct tape..

[trubleshtr]

Maybe the cylinder has blow by in it?

with air lines off operate the vlve manually and makesure air comes out the lines. put back one air line and actuate the valve manually again, and check the opposite side of the cylinder port (where the other air line would go) Is there air coming out? if No, repeat the proceedure for the other side of the cylinder. If air comes out of the cylinder port then it is in need of rebuild/replace. Also check that it is not leaking air out the front rod seal, infact you may want to give the whole pneumatic system a once over for leaks, and ensure your air system is putting clean dry air into the machine at the required pressure.

If all that seems ok check that the limit switches are being made to complete the cycle.
goodluck

[dtanner797]

haas is coming to look at it, will let you know what it was.