Air/oil consumption of spindle?

dead_nuts · Sep 12, 2011

I am looking at the Haas Mini-mill2 and see that the spindle uses air/oil for lubrication and cooling. How much air and oil does it consume? Does it just use air pressure to push the oil or does it mist the oil through the bearings?

I did not really want to have the machine constantly consuming air and running the compressor constantly. Is it like leaving an air gun open continuously? Or equal to a blast of air a few times a minute?

Also, how much oil is used and where does the used oil go? Is it consumed or recirculated?

Thanks,
Glenn

ARB · Sep 12, 2011

It's nothing to worry about. The only time you get much air is when changing tools. But that is not much. A decent 5HP compressor with a 60 gallon tank will not run much unless your blowing off your parts a bunch.

haastec · Sep 13, 2011

I believe the spindle consumes about .15cc of lube oil per 1/2 hour.

The lube oil is drawn in to the air line to the spindle and creates a mist for the bearings. If you ever run without coolant, you can expect to see oil droplets at the bottom of the spindle nose; this is normal. You should also be able to feel air coming out of the spindle at the same spot (Set at 15-18PSI). During most operations the coolant washes it away.

That same air pressure that feeds the spindle keeps a positive pressure inside the spindle which keeps the coolant out.

The only time the lube system is running is when the spindle is running and/or any axis is moving. If the machines sits idle for more than a couple of minutes, the lube system stops pumping and the air supply to the spindle is stopped.

Hope this helps.

dead_nuts · Sep 13, 2011

Does the spindle have a separate reservoir or does it use way oil? Where does the oil/air exit? Are the bearings sealed or do they have a shield?

ARB · Sep 13, 2011

It uses the way oil. Again this will last quite a spell too. On a small mill you probably won't use 2 gallons a year unless you're running it non stop.

KenFoulks · Sep 14, 2011

Here is some info from the Mechanical Service Manual:

The following gives the range for each type of spindle:
Lathes = 1.0cc every two hours.

40 and 50 Taper = 1.5 to 2.5cc every four hours. Set spindle air pressure regulator to 17 PSI for vertical mills, or 25 PSI for horizontal mills.

30K 30T = Airmatic Pumps (These pumps are identified by the addition of a solenoid on the top of the pump). Set spindle air pressure regulator to 25 PSI for 30K spindles and 20 PSI for 15K. Airmatic Pumps - Disconnect the air/oil line at the check valve. Manually energize the solenoid 30 times, holding it for 2 seconds each time.

Each pulse from the pump will deliver .01cc for the 30K 30-taper, or .2cc for the GR 15K. After 30 pulses, .3cc for the 30K or 6cc for the 15K, should have been collected per injector (The 30K spindle has two injectors).

SPINDLE PURGE AIR
The spindle air purge system is designed to keep contaminants from entering the spindle housing and possibly damaging the bearings. Spindle purge air is only used on grease packed spindles. An air pressure to the spindle purge is adjusted using the regulator on the back of the machine.
Set the air pressure between 3-4psi.

dead_nuts · Oct 25, 2011

I got my new MM2 installed last week and I was very surprised (disappointed) at the amount of air the spindle consumes. I calculated it to be 2.5CFM. This is just the spindle running with the 15PSI solenoid engaged, it shuts off after a minute when the spindle stops. This causes my 30gal air compressor to run for 45sec every 3 min.

Does 2.5cfm sound like too much for just the spindle bearings, I know the spec calls for 4cfm, but I assume that includes drawbar and spindle bore/tool holder air blast during tool change. Can I reduce the pressure to less than 15psi?

What type of seal does the spindle use, I can feel the air blowing out around the spindle. It must only have a shield or they forgot the seal?

I think this is too much air for the machine to use, not even adding in the tool changes. To me this places the burden on the owner. Why not use better or larger bearings so that air/oil cooling is not needed? There are other brands with faster spindle that are just grease packed. Even the high speed option on the TM mills are greade packed. Why does the VF, MM, MM2, DT-1 etc require air/oil lubrication?

Bryan33 · Oct 25, 2011

Hi I am a tech out of the factory. Please do not touch this system. It is set up to send the right amount of oil to your spindle bearings. You simply need a bigger compressor.

Tim in D · Oct 25, 2011

Hi Dead,
My MM used alot of air too when I first got it. One thing I did was reduce the amount of air going into the P-Cool unit. They have a pc of tygon tube running from inside the spindle cover (large pc of sheet metal on the Z axis)and threaded thru the metal conduit attached to the back of the P-cool case. Inside the case the tube is open-ended and purges the P-cool circuit board in there. I put an orifice into the open end of the tube and reduced the amount of usage substantially. I also found a very leaky connector inside the spindle cover. Still uses quit a bit of air but I can live with it now.

Tim in D

dead_nuts · Oct 26, 2011

The machine does not use any air while it sits idle after the spindle time out. The optional quick release fitting they install was leaking when it was first powered up, so I removed and installed a plug. I don't use any quick release fittings in my shop, they always seem to leak after a while.

I do plan to eventually get a larger air compressor, but that won't change the amount of air the machine consumes, just how often the compressor runs. My compressor has a 100% rating and is only running 20% now, so a new compressor is not needed.

I want to see if the air blast during a tool change can be bypassed. That consumes a lot of air and is not needed since the machining I do is very light and the the tool holders are not going to be covered with chips. There is a large main pressure tube that runs up to the head that connects to the drawbar actuator and pressure sensor. I will have to remove the head cover to see if the air blast has it's own connection? Or it might be built into the actuator?

haastec · Oct 27, 2011

dead_nuts said:
The machine does not use any air while it sits idle after the spindle time out. The optional quick release fitting they install was leaking when it was first powered up, so I removed and installed a plug. I don't use any quick release fittings in my shop, they always seem to leak after a while.

I do plan to eventually get a larger air compressor, but that won't change the amount of air the machine consumes, just how often the compressor runs. My compressor has a 100% rating and is only running 20% now, so a new compressor is not needed.

I want to see if the air blast during a tool change can be bypassed. That consumes a lot of air and is not needed since the machining I do is very light and the the tool holders are not going to be covered with chips. There is a large main pressure tube that runs up to the head that connects to the drawbar actuator and pressure sensor. I will have to remove the head cover to see if the air blast has it's own connection? Or it might be built into the actuator?

You keep looking to disable critical machine functions; STOP!

Air is REQUIRED for proper operation of the spindle. Air is REQUIRED for proper operation of the drawbar. This machine requires air to function properly so please accept this fact and stop trying to defeat the system.

mikeknell · Oct 27, 2011

Oh, the joys of getting a new MM2 (I have no complaints about the machine).

When I got mine (a couple of years ago), the Haas tech commented that the air/oil spindles were quieter than the grease packed spindle, so consider that to be a good thing.
The bad thing is that it does use air. Your machine uses about the same amount of air as mine (mine typically uses 3 cubic feet per minute with a tool change every 30 seconds).
You will probably have to bite the bullet and buy a better compressor, a refrigerated air drier, and another air tank (or two).
Compressed air is an expensive part of machining that you won't understand, until you have your own machine.

dead_nuts · Nov 1, 2011

haastec,

Please reread my post, no one is trying to disable the spindle air or drawbar -that would be stupid.

The spindle head uses air in three ways:

1. spindle bearing air/oil
2. drawbar actuator
3. blowing huge volume of air down over tool holder during the entire tool change operation

I want to see about reducing the air used on #3. It will be clear to me by removing the head cover, but with the low ceiling it is a pain to remove. So I will wait a few months when I have time.

Do you know how it is plumbed? I assume that #2 and #3 use the same soleniod, but from there are there two lines branching out? Or is #3 built into the drawbar actuator (like with bleed ports) which would be difficult to bypass.

If there is a seperate line, I want to add an additional soleniod to which I can either reduce the time it blows air (short blast) or shut it off entirely when I am only doing light machining with no chance of chips getting to the holders.

claya · Feb 23, 2013

How do I bleed air from the spindle oiler lines? We just got a used kitamura Mycenter 1, and the spindle oiler has air in the lines. The compressor runs continuously. Do we cycle the pump without air pressure? Or disconnect the oil lines and manually fill?

Kevin Wilkins · Apr 18, 2013

I realize this is an older thread, but I recently bought a used 2001 Mini Mill with an air/oil spindle and our local Haas Guy came out to set it up yesterday.

In answer to the poster's original question, it IS just like have a constant air blast going all the time the spindle is turning. It uses a TON of air. I have a fairly large piston compressor and it comes on every 5 minutes. I expect this would kill the compressor within a couple of weeks or else I would be limited to using the machine maybe 2-3 hours per day for no more than an hour at a time.

In other words: forget about it.

If you don't have a serious screw type compressor with air dryer, etc etc do NOT get one of these machines with the air/oil spindle.

I've been running a 2005 TM-1 with a packed grease spindle since 2005 and it uses virtualy no air. Only air used is when you do a tool change. I have it on a smaller, insulated compresor fron Junair. No problems at all.

Now I have a Mini Mill that I basically cannot use.

Luckily our Haas Guy has a company here in Germany who can take my spindle and convert it to packed grease bearings. This is also costing several 1000 bucks which I wasn't planning on spending, but I got no other choice.

So if anybody is reading this wondering how much air you'll need, you'll need a LOT! You'll need a screw type compressor system, not a piston engine and dryer and the whole works.

I wish I had read this thread before buying the machine... but at least I have a way out rebuilding the spindle.

machineit2 · Apr 18, 2013

There is a regulator on the back of the machine just for that spindle air. You need to turn down the pressure so it does not use so much. My VF-2 was too high when I got it and I adjusted it. You should not be using that much air.

Mike

Kevin Wilkins · Apr 18, 2013

The Haas Guy made sure evrything was properly adjusted. He's been doing this job forquite a few years and I do think he knows what he's doing. He says they just need a good deal of air...

machineit2 · Apr 18, 2013

I hate to disagree with your Haas guy, but I do!

It's your money. Hope he is not the one doing the spindle for you.

Mike

Kevin Wilkins · Apr 18, 2013

As far as I can see, there's no way to adjust the air pressure going to the spindle. The main air inlet needs 90 psi and that has a regulator. I'll try and take a few pics of the rear of the machine, maybe you can point out what you mean?

UPDATE
I do now see what you mean regarding the air pressure adjustment to the spindle, sorry for being mixed up before. I'm in the shop now and double checked and the pressure is set to 17psi which is exactly what Haas specs call for.

machineit2 · Apr 19, 2013

Regardless of what the gauge says, you need to turn it down. The air coming out around the spindle should be just barely heard and felt with you hand. Mine said it was the correct pressure too, but was not. You have to remember that the gauges used, if like mine, is a 0 to 120 or so gauge and not good for showing lower pressures. The air is just to keep stuff out of the spindle and does not need to consume so much air.

Good luck. I was stationed n Germany in the early 70's when I was in the army. In Schwabach near Nuremberg.

Mike

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