[tjamscad]

There is a documented proven procdure for fixing the Haas stick spindle tapers. located here I hope this helps everyone out there with a Haas spindle.

[tjamscad]

"The insert is through hardened tool steel. The insert is 2 inch diameter and 2.05 long with a taper inside leaving material to remove after the insert is installed. To remove the original taper I bore the spindle 2 inches deep to create a .0015/.002 press fit for the insert OD. Boring the spindle two inches deep leaves approx .05 sticking out. Freezing the insert in liquid nitrogen reduces the size by .006. This allows the insert to easily siip in the bored hole in the spindle. I program the machine to bore the insert taper. I program two tapers to create a concave face of the taper. This allows the taper to contact the tool adapter in two places - top and bottom. This is the FIX - I have had it in 5 Haas machines - VR11, VF10, VF6 and two VF4's. We have no tool sticking, no more tool runout than when the inserts were installed. The machines cut better than when new. I tell people this turned the Haas machines into Mori's.
Haastec - Don't believe me? It is not possible for me to care ANY less what you think. Before I put the insert in the VF10 I had Spindle Grinding Service (from Michigan) grind the taper in the VF10. We ran the machine for two shifts. After running the two shifts the Spindle Grinding Service technician checked the taper and told me it needed ground again. Your spindles tapers are ****. Your company has been apprised of this fix (many years ago) and has chosen to ignore this issue.
Your machines are fine machines - NOW - after the insert is installed.
Just sayin
thanks

BTW - the inserts have been in the machines for more than 5 years each - the VF6 and VF10 for 10 years.

this was also posted in the other thread mentioned by Haastec

BTW (2) - I am in Wichita Kansas

316 258 0953"

[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