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Reports of spindles not harden?

Djstorm100

Cast Iron
Joined
Jul 26, 2014
Location
Richmond
So this came up on FB post in the Haas group. Some owners (VF2-4) spindles are not harden and holders are getting fretting corrosion.

Going to Tech Day this weekend to put my hands on a new VF2/3

Has any new owners experience this? I figure pull studs could be a cause of this other than a bad grind on the spindle/holder
 
The spindle taper should be in the mid to high 50's Rockwell C to my understanding, if they're truly soft it's a major QC flaw. But I've heard nothing about this until your post, do you have any supporting evidence?

I don't think pull studs would do this unless they're too long, but Haas studs are well known and installing the wrong ones seems unlikely.
 
sounds like a case of BS .. I Have multiple Haas mills dating from 6 years old to this year and have seen ZERO spindle problems . Every spindle gets the 20 min warm up "EVERY" morning and they all spend most of there life running 12k all day long ,, The only time I have seen any fretting was with some super cheap holders I got off Ebay for tap holder. as long as I run Mori, Techniks or shars holders they seem to work out good ,, About twice a month I put a finger full of red grease on the pull stud and let it lube up the pull stud retainer ..

what ever you do don`t buy cheap pull studs ,,,, If you have the money buy T.J.Davies ( I use them in big face mills and boring heads ) and all smaller holders get Techniks
 
Just FYI about fretting corrosion. It has nothing to do with how hard something is, it is about close fitting parts, or close but ill fitting parts under vibration creating fretting. Weak draw bar pull can be one cause of this. Poorly ground spindle bores and tool holder shanks another.

Dave
 
only spindle issue I'm aware of ( I have had this happen first hand in my 2006 vf2ss) is the spindle motor itself having being built with the wrong bearings ( had a steel seals and werent rated for high speed). in 35 years of working on cnc machines, I have yet to have a motor bearing failure til recently. had a rear motor bearing failure and thought it was a coupler failure. til I went to replace the coupler and the spindle would lock up. after removing the spindle it was easy to see the spindle was fine. but the problem was in the motor. found the motor shaft to be about .003 undersized as well. this caused the bearing to spin on the shaft , eventually welding it to the shaft due to heat. also causing the grease to cook out of the bearing. It was a mess to get apart.
 
Don't put much into anything in that group. I'm a member just for the entertainment of some really incredible stupid stuff that goes on in there. You got the one guy that admitted he went into debug mode to find a way to bypass the option codes and screwed the control up so bad Haas had to go and fix it, then yet he bitched because they charged him for a service call. Then recently the one guy slammed the spindle so hard he broke the tool in the middle of the taper and was bragging Haas fixed it for free. I'll bet this spindle thing is some knob Jockey using cheap tools then not wanting to admit how he screwed up the spindle.

I'm not sure if you have ever visited Haas but to get a spindle out of there not hardened would be a one in a million thing and I guarantee Haas would have been all over it at first mention.

Here's another good one posted in the Haas group from the guy claiming a dirty spindle yet the retention knob shows it's not even a Haas
71641041_10220120600550477_7713924957704552448_n.jpg
 
IF the fretting is true it's a bad tool holder or not enough pull in the stud resulting in micro movement/vibration while cutting.

A few other reasons could be a loose pull stud, or overtightened pull stud resulting in swelling of the top of the taper allowing the bottom larger diameter to dangle (on a micron level)
That would fret a spindle pretty quick.
 
Here's another good one posted in the Haas group from the guy claiming a dirty spindle yet the retention knob shows it's not even a Haas
View attachment 267846

I don't even care about the pull stud, I'm just glad it wasn't my machine that had that massive failure at the big end of the taper. I would guess that at least part of why it happened was bad (acidic) coolant, as the corrosion on the remaining taper doesn't seem to be "just" fretting (at least, IMO), and if a crack was present at the big end then fatigue could have been accelerated by chemical (corrosive) action.
 
Who the hell uses rusty ass rotten tools like that anyway? LOL. Gosh even our old beater Fadals we used to have that nobody cared about had better looking holders than that. What a joke.

Yeah I'll take that guy's word for it. Obviously he knows what he's doing.
 
Talked to the gent and it's the dog legs that don't appear to be harden. Not a replaceable item. Have to replace the whole spindle. He said you can take a file to them

75233770_757042701395591_1400075505029349376_n.jpg


75380137_258830021687764_6323521358248542208_n.jpg



Just came back from South Tec and Doosan has really caught my eye DNM 4500s to be exact.
 
Talked to the gent and it's the dog legs that don't appear to be harden. Not a replaceable item. Have to replace the whole spindle. He said you can take a file to them

View attachment 268020


View attachment 268021



Just came back from South Tec and Doosan has really caught my eye DNM 4500s to be exact.


Most machines with integrated drive keys are only case hard so they don't snap off. That's a big difference than an unhardened spindle. Like I said, That group on Facebook is entertainment only. Watching one post now where some idiot was bitching he was down for a day not realizing the E-Stop was in.

As far as Doosan? Excellent machine backed by a great company. I have been working with Ellison for many years and they do their best to keep the customer happy. The only problem I can see is since they lost Mori they still have old customers they have to support without the help of Mori. Seems they are getting a bit back logged in service work since the Doosans are flooding the market nowadays. That being said, If I wanted one I wouldn't hesitate to buy one tomorrow. The quality is good, and the build is good so needing service is rather uncommon.
 
My money is on the orientation to the tool changer is in need of adjustment. From what I see its on one side of each lug and opposite normal clockwise rotation.
just saying.
 








 
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