Tool stuck in spindle

[PBMW]

2000 Haas Mini
Ran fine yesterday. Fire it up today, home it and get a tool fault. Do the toolchanger recovery, Tool will not release...you can hear the solinoid, but no joy...

[volthause]

Welcome to hell.

We had that same problem on 2 new VF-2s we have. For the first month we had them, neither one of them really cut any chips at all. They were constantly getting tools stuck in the spindle.

After going around in circles with Haas (they claimed it was our toolholders not being good enough first (they were and are), then that our pull studs were the fault because they weren't the Haas brand (even though they were more than comparable) they finally concluded that it was the umbrellas style tool changer that was the culprit. They replaced both with the vertical style and it's been smooth sailing ever since.

I still have no idea why.

[artin51]

I've had this happen a few times after heavy cutting. Does the carousel go towards the tool and the tool just doesn't realease? If that's the case, while the carousel is in postion to pick up the tool, give a couple of shots with a rubber mallet to the other side of the tool holder while the solenoid is open. Usually works for me....

[PBMW]

Finally figured that "What the heck...it's a Haas" Used a pry bar and out she came.

[Geof]

Pry bar, rubber mallet, aluminum drift with a big hammer; used them all.

We did discover some toolholders would stick more than others so we stopped using them for prolonged heavy cutting.

On our VF0 we had really bad sticking until we put an air reserve tank downstream of the regulator; this reduced the pressure drop when the tool eject cylinder operated and sticking became very rare on that machine.

[PBMW]

This machine has been actually quite reliable. Sometimes the toolchanges are a little noisy, I spray a little WD40 up in the spindle and work the tool release button and that cures it for a while. Wasn't doing anything heavy. It's a Minimill fer Gawds sake. I think the cycle time was about a minute for that tool. Face and a bore gets interpolated, Might be a min anda half total cycle time. This machine is running secondary to my Akira Seiki so it sits untill the part change and deburr happens on the other machine...Prolly 5 min down time between cycles. My point is that there was little load to generate heat in the spindle. Strange if ya ask me...

[Geof]

Forgot to mention we also try to remember to wash out the spindle taper and the tool holders with methanol to remove coolant residues. This does make a difference because the residue can be very sticky.

You can also get problems with a sticky solenoid valve. If the air does not turn on quickly the eject cylinder moves slowly and does not develop enough impact to knock the tool out. I had this problem on a SuperMini in my home shop that did not have good clean dry air. Pouring methanol down the airline solved that one, followed by rigging up a trap for moisture.

[dertsap]

if the stud is a little too tight the taper will swell , some people believe it most don t but ive seen the difference many times over with 50 tapers , all the machines at the last company had a different stud so we were always swapping studs in and out of those holders , two machines in particular were sensitive to this , anytime a tool stuck a few times then i would retighten the stud , 8 out of 10 times that would solve the problem .

under normal circumstances the studs should only be snugged up and lock-tited

[Vern Smith]

For what it's worth my local Haas operator told me to spray dry lube on the tool holders. He also recommended putting a swab on a stick up the spindle taper to clean any grease accumulations from the draw bar clamp.

Despite all this mine still stick after heavy cuts and make a hell of a clunk when they leave the spindle. I guess I'd better talk to Geof about the air tank.

Vern

[mc-motorsports]

[QUOTE=Geof;489558] If the air does not turn on quickly the eject cylinder moves slowly and does not develop enough impact to knock the tool out. QUOTE]

+1

The CAT 40 drawbar smacks the back of the retention knob. The clamp/unclamp piston has to build enough pressure to overcome the springs on the drawbar, plus accelerate the drawbar to give it that "umph" so it will actually impact the tool out of the tool taper.

And yea, after extended use especially during heavy cutting, the tool will tend to suck up in the taper a little more, makes it easier if the spindle gets hot. Then the tools are a little harder to eject, it's known issues with CAT and BT tooling.

MC

[Geof]

Originally Posted by Vern Smith ....Despite all this mine still stick after heavy cuts and make a hell of a clunk when they leave the spindle. I guess I'd better talk to Geof about the air tank. Vern

I will preempt you.

Get an airtank with a capacity of a cubic foot or two.

Take the airline of the outlet of the regulator and install a tee fitting.

Reconnect the airline to one end of the tee and connect the tank to the other.

Use large diameter fittings and large diameter hose.

With this modification you should hear a distinctly more solid 'clunk' when the solenoid opens and the release piston operates.

[PhillipM]

We had the exactly the same problem with our VF4 - running it at 7500rpm for a couple of minutes @ 2500mm/m doing some ally work - tool got stuck, wasn't the specific holder as 2 other tools did the same, it must be spindle heat causing a shrink-fit as after limiting all the tools to 7000rpm max we've had no problems.

Well, bar being missing 500rpm-worth of extra MRR in ally, which we weren't too happy about...