[SBC Cycle]

Needless to say, I've tried oil, WD-40, silicone based lubricants trick. It still sounds like a shotgun blast at it's worst.

[tjamscad]

Then you should try stustev's insert.

[haastec]

One of our new VF-2s does this constantly. It starts about 10 am on a normal day but gets rough as early as 9 am on a hot day. I have two of these machines bought at the same time and one difference between the two is the spindle cartridge is actually warm to the touch on the machine that "pops". I was told that they should never be warm, ever. They are 15,000 RPM direct drive oil cooled spindles.

Using an infrared heat gun I have been recording the temperature each morning after running the warm-up. It is not uncommon for the temperature on the outside of the cartridge to be 104-106 degrees F after a 20 minute spindle warmup (Program O02020 SPINDLE WARM-IN). It only gets warmer as the day goes on but never quite "hot". Haas has told me that it shouldn't be that warm yet they haven't found a reason to come look at it. I can definitely say the warmer it gets, the louder the bang.

If it is under warranty, then make them come and look at the issue. That way the service call is on the books and is associated with your machine. This will help in case the problem drags out past the warranty period. For any intermitten warranty issue, ALWAYS schedule a service call whether is can be reproduced or not. Haas has a good reputation for after warranty coverage for issues, but it will help immensely if there is a good paper trail.

I would not try the spindle insert repair unless you are willing to void the warranty on the spindle.

Good luck!

[SBC Cycle]

Thank you for the suggestion haastec. I mentioned the higher than normal heat on the spindle to the HFO tech again today but I will definitely follow your advice and phone in a service call about the loud tool change as well. They will be here again next week anyway, 2 birds 1 stone. My experiences have been largely positive with Haas service. Thankfully service calls are a relatively rare occurence, these Haas machines have been very reliable. This problem has not put the machine down, more of a nuisance than anything. I thought I would share my experience with the relation to the spindle heat.

Thanks again!

[Rockyr49]

I need to clear something up on this thread. I have worked for Spindle Grinding Service Inc for the past 22+ years. I have handled the calls that come in from the Wichita area. I have NEVER told anyone that their taper needed to be reground twice in 2 shifts. No spindle taper is ever going to wear in 2 shifts. If a machine is crashed and the taper damaged, then it will need more work. I have seen that, but NEVER have I seen a taper wear in 2 shifts. If this poster remembers me saying that, then his memory is faulty. We get many calls on sticky tools. We fix them by regrinding the taper back to proper specs. The main causes we see of sticky tools are these. Worn, bell mouthed taper. This is normal wear and happens to all tapers. Poor tool knockout. This is adjustable on most but not all machines. There should be a positive knockout of about .015". Heat. A spindle can get hot from an extended cut or improper cooling system. Put a cold tool in a hot taper and you have a stuck tool. Also the unclamp cylinder can have something to do with it. A bad seal can cause a lack of force at the end of the stroke. This could result in not enough force to knock the tool out.
As far as Haas goes, we don't see any more problems with those than any other machine. The spindles are no softer than others. The tapers are the same as any other steep machine taper. If the taper was the problem, then all should stick.
As far as the "fix" goes I have a couple of questions. What was done was effectively relieving the center of the taper. Why bother to bore the spindle and make a sleeve? Why not just relieve the existing taper? Also how much of the center did you relieve? The tapers are 2" long. How much contact do you have at each end now? One of the problems with relieved tapers is wear. Tapers bell mouth. Now once it bells past the front area of contact you have no middle. Shorter wear time between grinds. Also did the tools stick when the machine was new? Probably not or Haas would have been involved from day one. That means something has changed. What it it? Looks to me like you are fixing the symptom instead of the problem. There are virtually no machines built with relieved tapers. The huge majority of these run just fine. You probably have the only Haas machines with relieved spindle tapers. If that is indeed a fix, why doesn't every manufacturer make them this way.
Just my opinion, but I believe that I have learned a few things in my 22+ years and over 5000 taper regrinds.
But once more, make no mistake about it, Spindle Grinding Service has never told anyone that their taper was worn and needed grinding twice in 2 shifts.

Rocky Russell
Spindle Grinding Service Inc

[stustev]

Rocky Russell,
If you will look at your records for late 1999 or 2000 or early 2001 you will see Spindle Grinding Service was in Wichita at a shop for one afternoon and the next day. Your grinding technician ground the machine on the afternoon of the first day. When your technician returned to grind some more spindles the next morning your technician checked the spindle he had ground the afternoon before. In his opinion the taper needed ground again. At the time we were running 3 shifts and had run 2nd and 3rd shift between the time the spindle was ground and checked the next morning. We did not have him grind it. He ground the other spindles, we paid him and he left. Your company had been in town to grind some tapers at a large machine shop in Wichita. When he finished with the other shop he came to my shop.
It was at that time I determined to install a hardened insert.
The conversation I had with your technician revealed he saw no more problems with one machine brand taper over another. Be that as it may my experience was/is different. I did not argue with him as I will not argue with you. My experience is my experience - your experience is your experience.
With the insert the tapers do not bell mouth anymore. They run the same runout and do not stick after many years of service. Prussian blue shows no more interface than when the inserts were installed.

[Rockyr49]

Your recollection and mine are different. I remember coming in grinding one spindle and returning the next day. I was asked to check the first machine again. Upon inspection I noticed significant discoloration of the taper. I grabbed my scotch brite and WD40 and cleaned the taper. I rechecked the taper with my master and some blue. The taper was still good. After some discussion my opinion was that the machines would not handle the amount of material and speeds and feeds that were being used. I was told that the Haas salesman said that they would.
I won't argue with you either but I stand by my statement that no spindle can wear to the point of needing grinding after only 2 shifts.
We/I have spent many years cultivating our/my reputation in the field. The comment that I supposedly made does not uphold that reputation. I have to correct it when words are put into my mouth.

Rocky Russell
Spindle Grinding Service

[stustev]

Rocky,
To answer a couple of your questions.

I bore the taper to give me .0004 (.0002 per side) clearance.
The interface area runs from .125 to .375 top and bottom.

I agree with your opinion the original taper would not handle the feeds and speeds we use on the machines. The inserts handle the feeds and speeds. The rest of the machine handles the speeds and feeds just fine.

We try to program conservative feeds and speeds for 40 taper mills. We don't hit 100% on the spindle meter very often. When we do we reduce the feed to not run over 80%.

[greggv]

Our VF3 stuck like crazy. I cleaned the spindle bore with fine scotchbrite, and then a spindle cleaner tool, and no longer have a sticking problem at all.