Need Help!- VF 4 Tool change Pops, loud!

[Thinwater]

I am having to lube the pull studs on my tool holders 3 times a day on my VF 4. It has through spindle coolant and the 20 hp spindle. It was new in May 2009 and runs about 8 hrs a day, 5 days a week cutting 7075 AL forgings (AR 15 receivers). The tool changes make a loud pop as the holder comes out of the spindle. I had Haas out a couple of months ago and he just lubed/cleaned it and said to put a glob of grease on the pull stud of a tool every day.

My VF2 SS is starting to do this (Through spindle coolant also) on some of the tools but not nearly as bad as the VF 4 and it is over 2 years old.

All pull studs are Haas brand and all of the tool holders are good name brands, no china junk.

Is this normal? Any ideas of proper maintenance so this does not break something?

I have another VF 2 SS on the way and want to start out right with it to avoid any issues.

Thanks in advance.

JIM

[Pondo]

It's the taper sticking, not the pull stud. Cutting aluminum I assume you're running full 100% RPM? In any standard tapered spindle running at high RPM, the spindle opens up very slightly and the tool pulls up into the taper very slightly. Then it's real tight when it goes to change the tool. It's one of the benefits of HSK spindles that they don't do that.
I have had that happen on my VF-3 with 15K spindle, but not on my Minimill with 6K spindle. I have had that happen when running heavy cuts with a 3/4" mill in my VF-4's as well. The side pressure has a similar effect and I get a big pop when it changes (1.5" DOC @1600 RPM, 34 IPM, and .060-.100 radial cut). This is reduced by keeping the tapers as clean as possible, but with TSC there's only so much you can do.

[Pondo]

Just a thought - putting a bunch of grease on the pullstud of a TSC machine can result in grease being flushed onto the tapers, right? Grease on a taper will cause it to stick and pop, wouldn't it? I don't know, I never grease up the pullstuds. Just the V-grooves once in a while, especially on an umbrella changer machine. The only thing I use in the spindle or on holders is WD-40 to clean them and a drop of spindle oil to protect them.

[Chri$]

My VF2 was doing this a few months ago. It is the taper, not the stud. I lightly rub the taper with ultra fine 3M pad (as advised by our HFO), clean it good with WD-40, and don't leave tools in the spindle over night. No more popping.

[haastec]

Definitely clean the tool and spindle tapers regularly as described in the responses. Even when the tools look clean, there can still be a light film that causes the two tapers to stick together and create the popping sound you describe.
With the side mount tool changer this is not as big of an issue since the motion of the arm grabbing the tool helps to release it from the taper. Those with the umbrella style will definitely want to maintain the tools to keep from bending the carousel plate and/or dropping the tools during T/C.

[Haas__man]

I agree with Haastec - clean tools is the answer. Greasing the pullstud is a good thing to do. Don't do it every day though - do it once a week for a TSC machine or once per month for a none TSC machine- and only a small amount. Do not get the grease on the spindle taper or your problem will get worse.
If you are still having problems even when tools and taper is clean - then try applying a light oil - wd40 is ok. Apply the oil - then wipe the tool once to remove the excess oil.

Hope this helps

[Thinwater]

Thanks all, I wil pull and clean all of the tool holders. It is a full, 40 tool side mount so this will take a couple of hours to do them all and put them back in.

[HuFlungDung]

Seems that I recall some issue with gunk buildup in some of the air valves that control the Tool Release Piston. The issue was moisture related and required good dry compressed air to solve. Someone else may be able to fill in the details on what the cleanup involves.

[mikp5505]

people you need to rember your tool holders need to be taken care of the popping you are hearing is from not cleaning and REGREESEING the TOP not the whole pullstud.this is very important in machining if you tool holder has a black look or even starting to turn take some scotchbrite and very litely clean it the reciving end needs it to the trick is to spray WD-40 up in the holder and litely clean it spray it again befor you wipe it out just to knock the dust down DO NOT BLOW AIR UP IN THE SPINDLE YOU CAN HURT IT wipe it out and then spray a lite coat of WD-40 up in it.now back to the pullstud if you do not greese the top of your pullstuds at least once a month you need to get in the habbit of doing it two things can happen one your tools will start popping when tool change occures leading to your tool sticking in the spindle.the second thing and the worse is your drawbar will rust to the inside of your spindle and then you are looking at a new spindle this is coming from a haas service tech i have seen it happen to many times its not fun to repair and the bill is over $4000.00. use a white lithum greese if possable it has a very high temp breakdown meaning it takes alot of heat.. keep in check with your air pressure as well this is the first thing you should look at look in your manual and it will tell you what your air pressure should be for your machine.if you do your proper PM's your machine will keep making you money instead of costing you.

[double a-ron]

I have this same problem with my mini mill 2. I have actually had tools stick so bad the tool changer arm was bending trying to pull the tool out of the changer. When I got the Haas guy out to look at it he told me the same thing, keep the tools and taper clean, don't leave tools in the spindle over night, and grease the pull studs. He also added that being in an open air environment in south Miami isn't helping the the problem. He also said not to keep oil on the tool taper and not to wipe oil inside the spindle taper as that will trap dirt. You can see the problem this creates in Miami were the solution to most corrosion and rust problems is to soak the part in oil.

[mikp5505]

i live in central florida myself i was wondering witch haas tech told you that is it norm or was it bill or luis? if you are having that problem still it does not hurt for you to spray WD-40 up in the spindle if it makes you feel better do it in the morning and wipe it out but the WD-40 will not hurt anything.i have worked on many machines in miami and its not much different then here.also the type of material has alot to do with things if you are cutting carbon or anything that makes a dust its even harder to keep the sticking. if you use one tool to say tool one cuts for a long time and its cutting material that gets hot the tool and the spindle gets hot and it will swell and stick coolant cant cool in the spindle unless you have through spindle coolant and then the popping becomes buildup.i hope this helps you if not shoot me a message back..

[double a-ron]

Good call on the heat thing. I mostly cut 4340 and 01 and run the holy hell out that machine. Basically if it's running, the spindle is at at least 100%. My boss went for the mini mill when he should have gone with a vf-3, but it was our first cnc so live and learn. We were told by our tool reps (ISCAR) not to run coolant on steel because of thermal shock so the only thing keeping things cool in there is air.

It was Norm that told me not to oil the tools but I was asking about coating them in way oil, I never asked about wd-40, but that seems logical as wd-40 cleans then evaporates and oil doesn't. I'll give that a try.