[horst007]

I have a 2004 VF-3 with the pcool nozle. When adjusting it up or down it will at no specific interval return home then come back down to the tool. What could be the cause?

[pit202]

pcool goes up for homing or when it detects a manual manipulation of the noozle. maybe because of huge vibrations ?

[awesome83]

The switch inside isn't being triggered, possibly bad or misadjusted.

[Geof]

I have a 2004 VF-3 with the pcool nozle. When adjusting it up or down it will at no specific interval return home then come back down to the tool. What could be the cause?

You may be out of luck. I have a couple of machines about that age and the pcools did just that; wander off to the end of its travel. On one machine I had it replaced three times during the warranty and the technician said they were a poor design. Later machines do have a completely different unit

[Donkey Hotey]

Is this the black PCOOL or the gray one with the red Haas logo?

I have the one with the gray logo--November 2004 VF-2--similar to this one:


It too had a problem similar to what you're describing except it would cycle up and down a few times, then flag a PCOOL error on the control.

Taking the cover off, I discovered that the limit switches were not activating properly. It uses a lumpy cam that clicks one switch for each position and another that sends a limit signal at the end of travel to establish a 'home' position.

In operation, the nozzle travels to it's limit (triggering the home switch), then counts the 'lumpy' clicks down from there.

In my case, the 'home' switch wasn't being activated properly. It would hunt up and down, not find home, then error. It's bumped by a small spring lever that had simply fatigued. A pair of needle nose pliers and a gentle nudge is all it took to fix it. It's been fine ever since.