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Haas spindle seals MiniMill / VF Spindle 2012 vintage

evotechcorp

Plastic
Joined
Sep 16, 2019
Can anyone tell me if the VF / MiniMill spindles are suppose to have seals top and bottom or if the oil just passes through? I'm throwing new bearings in my spindle and upon disassembly there are zero seals, not even traces of them however recesses exist in the top and bottom caps where it looks like seals should sit. Exploded view of the spindle shows what looks to be a seal of sorts...

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Then there is the recess in the cap...

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They are labyrinth seals, very close fit to the shaft with no physical contact.
Works with low pressure air supplied to the spindle when on and for a time period when turned off.

I believe that vintage spindle is also air/oil lubricated.

Let us know how this goes.
 
They are labyrinth seals, very close fit to the shaft with no physical contact.
Works with low pressure air supplied to the spindle when on and for a time period when turned off.

I believe that vintage spindle is also air/oil lubricated.

Let us know how this goes.

Yes, it is air / oil lube - any idea where I might start looking for the seals? I know Haas won't sell me anything that requires cracking the spindle open which leaves me to my own devices... But I also know that Haas only makes about 30% of the components in their machines and i'm 99.9% sure they're buying seals from someplace...
 
Yes, it is air / oil lube - any idea where I might start looking for the seals? I know Haas won't sell me anything that requires cracking the spindle open which leaves me to my own devices... But I also know that Haas only makes about 30% of the components in their machines and i'm 99.9% sure they're buying seals from someplace...

The labyrinth seals being talked about are machined into the parts of the spindle, they're not a separate item. So you should be set...
 
The labyrinth seals being talked about are machined into the parts of the spindle, they're not a separate item. So you should be set...

Very interesting, The cutaway view that I included above shows some sort of seals top and bottom, there's also a .280 x 3.5 void machined into the caps as well as what appears to be an o-ring groove. Sure looks like something should fit there but if not that would explain why there are zero traces of existing seals...
 
I mean no insult by this question: Have you done this work before?

You wrote "..toss a set of bearings in." proper bearings for this are very expensive and fit up very particular and precisely to six decimal tolerances. The spindle should be dynamically rebalanced and a very careful breakin procedure applied.

Not your F150 front wheel bearings mind you.

It is a wise investment having a specialty service shop do this - worth the price of a warranty alone.

Just experienced advice, not a lecture.
 
I mean no insult by this question: Have you done this work before?

You wrote "..toss a set of bearings in." proper bearings for this are very expensive and fit up very particular and precisely to six decimal tolerances. The spindle should be dynamically rebalanced and a very careful breakin procedure applied.

Not your F150 front wheel bearings mind you.

It is a wise investment having a specialty service shop do this - worth the price of a warranty alone.

Just experienced advice, not a lecture.

I appreciate your concern - Have I rebuilt a machine spindle? No, my background is in aerospace technologies in the USAF so I'm pretty comfortable putting bearings in a 6000 rpm spindle... They let me do it on a 30,000 rpm hi-bypass turbofan where lives are on the line. If this was a higher speed spindle I would send it in for sure for balance and run-in. The bearing set came with races machined for specific preload based on a torque value included with the bearing set, just a matter of having a clean room type environment and the proper tools for setting torque on the castle nuts. My ignorance is with the seals if in fact they even exist, it's a bit alarming to open up anything mechanical and find a void that looks to be machined to fit a specific component - And the fact that the manufacturer will offer no assistance, parts, or IPBs of the component.
 
:D Fair enough!

I learned of labyrinth seals in my work on steam turbines and related pumps. I suppose what we called 'spill strips' the seals along the outer and inner edges of the blades and staging are a close analogy, the gasses are trapped in a stall condition. On the spindle with clean pressurized air supply a positive flow out prevents contamination. Simple and no contact, no wear.

Carry on and do please tell us how it goes, might just give me the confidence to do my own one day if needed.

May I ask the specifics of the bearings, cost?

PS: Yes it's annoying Haas keeps its cards close to their chest. I suppose they got the idea from Apple.
 
:D Fair enough!

I learned of labyrinth seals in my work on steam turbines and related pumps. I suppose what we called 'spill strips' the seals along the outer and inner edges of the blades and staging are a close analogy, the gasses are trapped in a stall condition. On the spindle with clean pressurized air supply a positive flow out prevents contamination. Simple and no contact, no wear.

Carry on and do please tell us how it goes, might just give me the confidence to do my own one day if needed.

May I ask the specifics of the bearings, cost?

PS: Yes it's annoying Haas keeps its cards close to their chest. I suppose they got the idea from Apple.

It's all about systems knowledge - I have no problem rebuilding an aircraft or a spindle but have limited understanding of a steam turbine and would lock the toolbox and walk away... To be fair If i'd pulled the spindle core out and it had heat shrunk collars instead of castle nuts I would have put it right back together and sent it away to the pros. So, bearings - upper single bearing was $425.00, the ground matched pair of lower bearings were $1200.00. Theres plenty of places online to buy "pre-packaged" spindle bearing sets which probably would have been fine in my 6000 rpm spindle for under $500.00 / set but I wanted to know for certain that I would achieve proper preload so I went with National Precision Bearing. The rep was able to use the inner / outer race grind tolerances that were laser etched on my original bearings and determine the preload and specify the replacement set. I will say that my spacers between the bearings were ground identical, if they had been ground different heights it would have throw a wrench in determining the preload. The real test will be how many machine hours will I get out of my shop rebuilt spindle? Only time will tell, Unless of course I can't solve this seal issue.
 
Run it - you don't have a seal problem!

I recommend using Mobil 1 as Haas suggests, check and adjust oil output and run the break in program. Run a spindle warm up daily.

I am impressed, do keep us posted!
 








 
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