haas vf2 tools jam up on tool change

ok here is the latest conclusion, tools mostly jam up after a roughing cycle high-speed-milling or after a normaln roughing cycle, meaning that the tools stick to the spindle when it is working hard in materials.

also, if you stop the machine after that cycle and manually remove the tool, there will be a loud metallic sound like something inside spindle is hitting the pull stud hard (like hitting hammer with other hammer) and the tool will be like a projectile, you need to hold your hand firm on the tool holder so it doesnt make you loose grip on it and it becomes a projectile hitting table.


I've tried cleaning every tool holder and spindle, multiple times, I've used both fine and previsouly used sandpaper to clean debris and material buildup from tool holders and spindle, also to reduce smoothness of the surface of taper.
I've also used scotch brite to do the same thing, after which I cleaned all surfaces with washing liquid and then soft and clean rag.

I've even tried to use small amount of grease on top of the pull stud and tried to jam it multiple times inside spindle to get the grease going inside mechanism.

That all helps for short period of time, maybe in making few parts without tools to jam up, but still there is some banging ocassionaly.
And then the problem occurs againa and now it has become more frequent.
First the problem occurred few times a day, now it might happen as many as 10 times a day.

If you search, you will find several threads on this topic here and on the other common CNC forum. If your spindle taper and toolholders are as clean as you say and you are not dousing them with coolant upon tool changes, I suggest monitoring your air pressure during a tool change. Even though my supply air is good (600gal tank) and it was plumbed with proper sized fittings/lines, I was still seeing a >10psi drop in pressure during tool changes, resulting in the exact behavior you noted. After adding a small (6gal) tank to the machine to function as an accumulator, I haven't had any more problems.



However, I have come to accept that something about the design of the spindle on my VF-2 does cause tools to be ejected more forcefully if I machine for extended periods of time with high axial forces. However, this is still not a problem after adding the accumulator.

Mike

I started putting a little bit of Chuck grease from the lathe on a tool holder ever few days and all the popping has stopped completely. Just a dab smeared all over the taper of the tool that's going to do the most work. That seems to leave enough of a coating that none of the tools stick.
Jordy

mbraddock said:

If you search, you will find several threads on this topic here and on the other common CNC forum. If your spindle taper and toolholders are as clean as you say and you are not dousing them with coolant upon tool changes, I suggest monitoring your air pressure during a tool change. Even though my supply air is good (600gal tank) and it was plumbed with proper sized fittings/lines, I was still seeing a >10psi drop in pressure during tool changes, resulting in the exact behavior you noted. After adding a small (6gal) tank to the machine to function as an accumulator, I haven't had any more problems.

View attachment 174838

However, I have come to accept that something about the design of the spindle on my VF-2 does cause tools to be ejected more forcefully if I machine for extended periods of time with high axial forces. However, this is still not a problem after adding the accumulator.

Mike

Click to expand...

my air pressure drops over 20psi, 21-22psi approx.

the haas tech has seen it and said its "marginally fine" meaning it shouldnt cause this problem, but something does.

sometimes the tool change is effortless, and as quiet as it can be, sometimes it would pop and bang, doesn't seem to be air pressure related, because, as I've learned, the machine has a precharge of air supply inside, which acts like your accumulator, but I'm still curious of your solution, would like to try it but only if it is not that expensive and complicated to do, how did you do it and for how much?

another thing, the tool will jam even if there is only haas working, not any other machine, the air compressor has 250 litre air flow, but the haas requires 200 litre, so that shouldn't be the problem.

the grease does not help at all. tried it.

Fadal I ran had this problem. Dipping the tool holders in clean mixed TrimSol worked as well as anything to help lube the tapers. Keep clean and maybe a little way lube on the tapers. The machine did not like the spindle and tool holder tapers to be perfectly clean.

I was having the same problem on my Fadal with a real loud pop when it was time to let go the machine. Once I cleaned both the tool and spindle contact surface with some WD-40... back to smooth as silk. So, I now do this when I start up the machine in the morning for a full day of problem free releases. I also make sure I have some grease(small amount) on the pull stud.

The WD-40 also repels water-- so if water was an issue as well.. it this would help.

Likewise, they'll stick when in a low pressure condition-- twice we had a "do-gooder" turn the compressor off for the weekend on a Sat. that production worked 1/2 day while the machine shop had a full day.

Are you running coolant? The Haas has no spindle chiller, the coolant is routed along the outside of the spindle/head, underneath a sheet metal guard with an o-ring type seal to cool the spindle. Ran into this problem using a long roughing cycle with air blast. If you aren't using coolant, try turning the coolant on and pointing away from tool and see if it helps.

i have seen machines before that needed spring washers replaced. as they get used over years they dont quite come back all the way and machine has increasing problems
.
i have seen plenty of times maintenance fixes the problem. oil, grease, roughing up taper they are all going to have limited success fixing a mechanical problem

DMF_TomB said:

i have seen machines before that needed spring washers replaced. as they get used over years they dont quite come back all the way and machine has increasing problems
.
i have seen plenty of times maintenance fixes the problem. oil, grease, roughing up taper they are all going to have limited success fixing a mechanical problem

Click to expand...

Why are you "roughing up a taper"?

Mike1974 said:

Are you running coolant? The Haas has no spindle chiller, the coolant is routed along the outside of the spindle/head, underneath a sheet metal guard with an o-ring type seal to cool the spindle. Ran into this problem using a long roughing cycle with air blast. If you aren't using coolant, try turning the coolant on and pointing away from tool and see if it helps.

Click to expand...

i use coolant, haas has air spindle chiller, at least thats what haas tech told me.
the coolant is pointed to tool, holder and on multiple sides and angles dousing it.

allenp said:

i use coolant, haas has air spindle chiller, at least thats what haas tech told me.
the coolant is pointed to tool, holder and on multiple sides and angles dousing it.

Click to expand...

I'm pretty sure a VF2 does not have any spindle chiller, maybe a misunderstanding...? Anyways, if you are using coolant it is a moot point to what I was referring to. I don't know, call a tech in I suppose. Try to have them come maybe later in the afternoon when the machine has been ran alot and is nice and 'warm' to try and repeat your problem.

I have had this problem on our 2 year old vf2ss. I was using dupont teflon chain saver, dry teflon lube, on the taper and it works well. Ive seen this type of can hidden at our haas hfo for demo days so its their trick i guess.

I have since seen in the manual for troubleshooting a sticking tool that the pull stud needs grease. Ive had pretty good luck with this but definitely have to keep after it.

Im curious about the air pressure since you mention this, we have pretty low air pressure, 80-90 lbs so this could be part of mine doing this.


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