Post By BGL
Post By haastec
This Old Haas - spindle temperature
So last episode we lost the vector drive on my1992 VF-0, yea last post I said it was 1997, to late to fix it then. In any case, we sent the unit out had it repaired and reinstalled it, seems fine, start/stop, M03/M04, orient - seems fine!
I Ran the long warm up routine, takes 30 min to get to 7k for one min. I then went to install a tool and felt the spindle nose was warmer than usual. A check of the diagnostic page shows 84 degrees but this is the outer casing not the shaft itself. The drive lugs and taper were hot, too hot to keep in contact with! Mother always said I would make a poor devil has I have a sensitivity to temperature - quick check with an infrared thermometer shows 135 degree at the taper section. I have run the warm up before the death of the drive and though I never took the temperature it was always warm to the touch never hot. Ok, so you’re thinking - the drive has nothing to do with the spindle temp other then possibly over-speeding it; checked the rpm with a handheld digital tachometer, rpm is fine. This is the set up, more to the story and then the question.
As Paul Harvey would say: “Page two"
While the drive was out I took the time to replace the pressure gauge on the air regulator to the spindle lube/air line. The original gauge was broken and it bothered me that I had no idea what it was. Once the drive was back in and machine was powered up I set the pressure from the 12psi showing to the 17 that the manual states. So I was running the spindle at 5psi more then before. Now with the spindle heating up a comment in the manual gets me to thinking: ”12K &15K Spindles require higher pressure to slightly reduce the delivery speed and amount of oil”. So is it possible that this older spindle - it has the little bronze breather on the back side that air flows out when the spindle is turning, my thinking is it requires lower pressure to push more oil because of the lower restriction??
My manual is not the original, it is dated 2006 and the online updated one states the same 17psi for the VF series and 20psi for the high speed spindles.
So the question in my simple mind is: Is 17psi correct for this older design? Is there a way to trigger the spindle air/oil solenoid without running the spindle so I can confirm the oil flow, or can I just run it at a very low rpm. I’m thinking I should disconnect the line at the spindle and measure the oil output over time. 1.5 to 2.5cc every four hours per Ken Foulks posting.
My apologies for the lengthy dissertation, I’ve been drinking…
Was the coolant on and cooling the spindle as per normal use?
Thanks for asking; no coolant was on for either 12psi or 17psi running. This spindle design the coolant does not flow through the casting.
I had a 1992 VF-1 and Haas did an upgrade of the air/oil spindle system. It was replaced with one that had higher capacity. Do you know if yours was updated? At that time it was to cool the spindle more for less tool sticking.
I have no idea if there was nay sort of upgrade, doubtful as this machine was like my dog, misused and abused then abandoned.
You might want to contact Haas and check. They can tell by your serial number. They upgraded mine after about 2 months after I bought it new.
Best of luck----Mike
Spindle bearings going bad?
Well the old girl has been serving me well so far with over fourteen hours spindle time, however I was conservative keeping rpm not above 5k. Ran a job at 7k and its scary hot at 105f on the diagnostic display and 130F at taper face using an IR temp gun, needless to say tool release was with assistance from mallet.
[oil mist feed system, air pressure @ 17psi, oil flow confirmed, air flow from relief on side of spindle]
Thinking... belt is too tight.
So next day I loosened the belt, sort of scrunches as you turn by hand. With belt removed spindle turns free and quiet. Tightened belt "looser" than it was, 3/8" with light finger pressure, runs smooth, no scrunch, sound quieter when running. Ran warmup and worked up to 7k in ten min steps, temp on display 90F spindle taper face 120F.
So from my experience with other Haas mills this is too hot, am I wrong? - Thinking the bearings are bad but have only seen them fail as a complete lock up never this heating yet continuing to run?
Any recommendations of spindle repair shops?
Last edited by BGL; 07-07-2012 at 08:31 AM.
Reason: add text
Are you getting some visual evidence of oil getting through the spindle in the form of a droplet or two that forms on the spindle drive keys when the machine sits overnight? Have you checked oil flow in drops per minute through the oil mister unit? There is a test rate. If you've got any sort of oily mess up in the spindle housing, check that those plastic oil feed lines from the mister are not leaking the precious drops of oil before the oil gets to the spindle cartridge.
According to the service manual 150 deg at the taper is to hot. You noted that you confirmed oil flow, but did you measure the amount of oil to the spindle? As HuFlungDung asked, do you see evidence of oil at the spindle nose?
Originally Posted by BGL
Both to much oil and to little oil can cause overheating of the spindle.
Yes there is oil and I would not say it is excessive but definitely there. I plan to test/measure to get an "exact" amount per hour. What surprises me is it has run at 180F at the taper face for at least an hour, expected it to lock up but it feels smooth..
I attempted to remove it but no go, there is a huge spanner nut at the top, must this be removed first? It's a '92 era machine but my guide is '96 and only says to remove the six bolts at the face.
Thanks for the help!
If you are referring to removing the spindle cartridge, then you will only need to remove the 6 bolts on the mounting flange of the spindle. Be sure to disconnect the air/oil line and probably the fitting also before removing the spindle along with the drive belt if it is pretty tight.
Originally Posted by BGL
You may be thinking about this already, but I will say it anyhow. The spindle will drop out from under the head so be prepared for it when removing the bolts. Jog the spindle down to a block of wood, remove all belts, air/oil line fittings, and bolts. Slowly jog the head up while holding the spindle cartridge. (Much easier with 2 people, but doable with 1).
Reverse the process when installing.
Yes I am referring to removal of the spindle cartridge. Thanks for the description, I actually read the manual [this time] before I started and watched a tech at my full time job do this on a 2002 VF-4; always a good thing to spell it out though.
I put studs, brass washers and nuts set with a 1/2" gap to capture the spindle as well as a wood block, belts and lines removed and fittings capped.
No go, tapped with plastic mallet all around bottom, hit pretty good with a copper rod on the big spanner nut and 32oz ball peen; even reattached the tool release and tried that several times - as Yukon Cornelius says, "nutten!" Soaked with penetrate overnight and thinking about setting two 500w flood lights on either side to warm the casting "safely". But first I am running the motor with belt removed and air/oil line into a container as I type...
One hour produced a carefully measured 1cc of oil, that's twice the rate of 1cc/2hr from the manual...
The spanner nut - it had evidence of being "turned" does this affect the bearing thrust?
How do I reduce the oil flow, increase air pressure as for a 15k spindle?
ps. hour later, set up lamps, set block & spacer under tool changer so pressure is direct to hub... 0.0005" movement and not sure it was that much... TBC
Last edited by BGL; 07-09-2012 at 05:55 PM.
Reason: R&R Klondite Pete w/ Yukon Cornelius, update progress
Note to self: If you suspect the 6" spanner nut needs to come off before the 5" diameter spindle can come out - your probably right. And shimming a precision face in between bolts can't be good to maintain a round bore, you know this from torque plate honing cylinders.
Clean it up, put it back properly torqued without shims and run it!
Did you by chance take any pictures? I still cannot visualize the spanner nut you are referencing.
My apologies if I provided inaccurate info.
No apologies necessary, you had the best intent.
Here it is, there is a spindle for sale on e-bay that shows the nut - had a face palm moment when I found it. Guess it is an early design?? The shim is about .003" thick. I cleaned and stoned the face of the flange, removed a fairly large burr on the opposite side of shim, interesting. Cleaned everything and reassembled with the spanner nut only finger tight. Originally it was real tight and hard to remove and showed contact on only one side. I torqued the flange bolts 40 ft/lb. I swear the spindle turns more freely but I could be imagining it. I had left the spindle upside down over night hoping oil would drain out, did not see any. I will complete tomorrow and run another oil volume test @ 20psi to see if I can reduce the oil flow by half and test run... if no improvement it's coming out for a rebuild.
Well it’s interesting; you never know what you will learn.
Ran oil volume test @ 20psi and got less than 0.25cc an hour, so I compromised and set pressure to 18psi.
Next - and you may think this was crazy but I was desperate. One of the causes of overheating is too much/little oil. So I reasoned that way lube over time leaves a waxy film that is dissolved by alcohol. Could it be blocking flow preventing oil in/out? I do know that many high precision bearings use a phenolic cage and did not want to use a strong solvent. I attached a tube and flushed about a pint of alcohol through into a clean cup, nothing other than the expected globs of oil residue in the cup. I ran the spindle for an hour with the belt removed occasionally spinning it by hand to re-oil and blow out the alcohol, I think it was all unnecessary but it did not hurt.
All back together and ran a long warm up at 5%, 10%, 50% and 100%. Once the spindle was at 7k at the taper face with an IR temp gun the temp quickly rose from 108F to 120F+. I stopped to contemplate this.
This older model spindle has one of those little bronze pneumatic exhaust filter things that air flows out of supplied by a separate line. What if that is restricting the air flow? It could be there to cool as well as keep the labyrinth seal clear.
I took it off and blew through it; not having a new one to compare it to it was inconclusive although it did seem restrictive. So I reinstalled it and restarted the spindle at 7k, temp quickly rose to 120, 125, 128, I reached around and pulled off the muffler, 126, 123, 118. Within fifteen minutes it was down to 108 and stayed there for a full half hour, again intuition provides right. New one will be in on Monday and we shall see then. The next is to sweep the table and see where that rabbit hole ends…
Hope this is helpful to someone, someday.
With some of these older machines being brought back to life, I am sure you will help someone out down the line. Well done!
Way to keep at it and get things figured out. Those exhaust ports can cause some weird symptoms for sure. They are one of the first, and easiest, things I check for anymore.