We purchased a new VF-2 (15,000rpm) 3 months ago and have now encountered a serious problem. We have had 2 spindles destroyed in the last week. The drawbar has cracked and the tool holder has fallen out. From what we can see, it looks like the spindle orientation has some give and when a tool is grabbed from the tool changer (umbrella style), the gripping fingers from the tool changer rotate the spindle. When the next tool is put in place, the notches of the spindle are not lined up the slot of the tool holder causing a collision and ultimately breaking the drawbar. We have noticed extreme wear on the tool holders where the tool changer fingers grab, as well as indentations from ball bearings on the center of the length of the pull studs. Has anyone else encountered these problems? Haas is pretending everything is OK, I doubt our 3rd spindle will last the weekend. Any help would be very much appreciated.

If I were in your shoes, That machine would be Outta Here. I'de talk to the HFO and get it taken care of or I'd be calling my lawyer
Jim

The newer Haas use simple parameters to orient the spindle, do they not? It would seem to me that there should be no 'flex' in the spindle orientation. The reason I say this, is I have a Baldor vector drive on a knee mill, and when the spindle stops, it stays stopped, there is no free play in its rotation.

So I would get them to go over the parameter setting for the spindle drive, and see if it cannot be tweaked to improve its 'STOP' performance. Check the spindle encoder coupling for a loose setscrew, if such exists. My WAG :D

Or better yet call HAAS direct and tell them what your HFO said and who said it, ask HAAS Factory to officially tell you that this is normal. I figure all these spindles are being handled under warranty, no? In the meantime when you get up to 5 spindles I suspect that you will have somebody's attention. In the meantime you had better be actually documenting EVERYTHING and insure that you are using accurately balanced tooling etc.. so that they can not wiggle their way out and somehow blame it on your operation. Just my $0.02
By the way what are the specifics of the HAAS warranty regarding high speed spindles. Do they accept just any type of factory balanced tool holders including setscrew end mill holders vs. collet type only. Or does it go as far as saying it must be a complete balanced unit requiring a balance machine??

... We have noticed extreme wear on the tool holders where the tool changer fingers grab, as well as indentations from ball bearings on the center of the length of the pull studs. Has anyone else encountered these problems? Haas is pretending everything is OK, I doubt our 3rd spindle will last the weekend. Any help would be very much appreciated.

I have a VF2 15,000 rpm with the side mount toolchanger delivered 6 months ago and used regularly since then with no problems.

You should check that your tool carousel has not sagged due to the bolts holding the track rollers coming loose. It sounds possible that the spindle is not coming down far enough for the ball gripper to correctly engage the pull stud. You say the drawbar is cracked...by this do you mean the housing of the ball gripper? I can see this possibly cracking if the balls are resting on the OD of the pull stud.


I am puzzled that "Haas is pretending everything is okay". Surely these repairs are under warranty on a three month old machine? Have you spoken to Haas head office or just dealt with your local "Haas Factory Outlet"? I suggest you get onto Haas directly in writing. I have found them very approachable on issues that did not seem to be getting sorted out by the local service tech.

... Do they accept just any type of factory balanced tool holders including setscrew end mill holders vs. collet type only. Or does it go as far as saying it must be a complete balanced unit requiring a balance machine??

Dean has a good point. Have you been using the correctly rated holders? There is a specific standard for balance that must be used.

Geof,
What type of holders do you use with your machine. Prebalanced collet type or do you have a balance rig?

We are using Techniks prebalanced collet style tool holders, rated for 20,000rpm.

I have a VF2 15,000 rpm with the side mount toolchanger delivered 6 months ago and used regularly since then with no problems.

You should check that your tool carousel has not sagged due to the bolts holding the track rollers coming loose. It sounds possible that the spindle is not coming down far enough for the ball gripper to correctly engage the pull stud. You say the drawbar is cracked...by this do you mean the housing of the ball gripper? I can see this possibly cracking if the balls are resting on the OD of the pull stud.


I am puzzled that "Haas is pretending everything is okay". Surely these repairs are under warranty on a three month old machine? Have you spoken to Haas head office or just dealt with your local "Haas Factory Outlet"? I suggest you get onto Haas directly in writing. I have found them very approachable on issues that did not seem to be getting sorted
out by the local service tech.

The carousel was check for sagging after each replacment spindle. The first time, about 1.5mm sag was noticed (not enough to be problematice, i was told). The second spindle broke after about 10 hours of operation.

Yes, the housing of the ball bearings was broken. The OD is what we were thinking but the cause looks to be not from sagging.

The machine is under warrenty. Our dealer is saying everything is OK. A letter is going to be sent to HAAS on monday.

Geof,
What type of holders do you use with your machine. Prebalanced collet type or do you have a balance rig?

I don't run above 10,000rpm. Getting the 15,000 machine was a mistake; I took a cancelled order off Haas' hands and all the paperwork referred to 10,000 rpm. When the machine arrived it was a 15,000 rpm with high speed rapids but I did not complain.


boodoowaa;

Has the drawbar release adjustment being checked? If this was off possibly the gripper is not coming down far enough. It seems very strange that the machine ran okay for and while and then started acting up, something must have changed.

I has a serious vested interest in knowing if it is something that has dropped out of adjustment - my second VF2 SMTC arrives later this month!

I'm not up to date on the Current Haas 15,000 rpm spindles.
On the First Machine I had experience with, It had no Torque at 15,000.
I could stall a 1/8 drill in Aluminum.

That machine also had a duty rating.
Meaning I could run 15,000 rpm for only a short time.

Do they still have a duty rating?

What about the warm up cycle.

I had to Warm the spindle up through various rpms before running at 15,000.

I'm not up to date on the Current Haas 15,000 rpm spindles.
On the First Machine I had experience with, It had no Torque at 15,000.
I could stall a 1/8 drill in Aluminum.

That machine also had a duty rating.
Meaning I could run 15,000 rpm for only a short time.

Do they still have a duty rating?

What about the warm up cycle.

I had to Warm the spindle up through various rpms before running at 15,000.

Haas recommends the Warm Up cycle whenever the spindle has not been used for 72 hours (I think) or when the temperature drops below around 60 degrees F when the machine is not in use. We only run at 10,000 and have found that a Warm Up every morning prevents the spindle getting hot. If the machine is left for a weekend and then run up to 15,000 without the Warm Up cycle it gets very hot.

The torque at 15,000 rp, is quite good. I had a 5/8" two flute cutter take full width, 0.4 DOC and 150 ipm feed with a spindle load just below 120%. According to Haas the spindle is rated for 30 minutes at this load and indefinitely at 100% spindle load but we have never operated continuously under these conditions.

There is a 20min warmup cycle we run at the begining of every day (Haas says it must be run if your machine is idle for 2 days). I have not heard of a duty rating and have had no torque problems.

What did Factory HAAS have to say about your problem?

I had a problem on my VF-2D (7500 RPM). The spindle would orient to random places causing all maner of problems with tool changes. I dug around in head of the machine and found the timing pully on the spindle encoder came loose. Haas used some cheap aluminum set screw. I replaced it with a steel screw and added a backup screw to keep it locked in place. A simple adjustment of the spindle orient parameters and i havent had a problem with that machine in almost a year. I assume all of the ridgid tapping and heavy face milling we do was the cause of the screw comming loose.

BTW: we run spindle warmups on all of our CNC's at the beginnig of every work day. We have hundreds of hours on our spindles and have not had a single problem with any of them. VF-2SS, VF-2D, and MINI MILL.

I just had another thought. HuFlungDung was talking about spindle "flex" in the orientation and how the spindle should stay locked in place. Well I realized that all of the machines listed in my last post have a little "flex" in the orientation. I think this is on purpose to allow for a small (very small) amount of misalignment between spindle and tool changer. Think about it, the action of the tool change arm itself requires a small amount of rotation in the spindle to make sure the keys all line up when the arm grabs a tool in the spindle. The parameters are only set by eye anyway. Iv'e seen my HAAS tech do it, and that is how he told me to do it when I had the problem I wrote about earlier. It's all trial and error. Set the parameter and bring the tool arm over to see how close you are. I speak from personal experience, if I was told wrong please fill me in.

I'm sure your tech checked this, but under the head cover there is an encoder. The encoder is is connected to the spindle motor via a cogged belt. Obvious failure points are the belt (to loose/worn) itself, The sprockets (check the set screws) or a bad encoder/cable.
Verify its orienting to the same place, if its an umbrella style the dogs should be straight across (can't remember the spec on how much.) Orient spindle , indicate across the dogs. Move clear of spindle - run it for a few minutes and indicate again (Don't wipe out you indicator).

Most of all - Call the factory and talk to a service guy if the machine is under warranty (even if its not), they'll walk you through anything , and usually call your HFO to put them under the gun to get it fixed.

I am a service tech with the Haas factory. If you send me your serial number I can look up your company and give you a call. I would be happy to take care of this.

I am happy to say that our 3rd spindle has not fallen out and is still running. I am dealing with Haas directly but I am still waiting to hear what results they have. Once I know, I will post them. Thank you everyone for your help.