Yes, I have for about a year now. I have been struggling with high spindle temps when running above 6k and the subsequent tool sticking issue.
I have not taken temp measurements, just touch and no sticking.
What I really want is an N/C valve on the oil line, sight glass with a needle valve for the oil to set the drip rate. When not using the spindle oil still flows and settles in the line. Once you command the spindle air flow carries this slug of oil and this adds to high temp (counter intuitive but true)it takes some time to settle and perhaps by then the job is done at high spindle temps, do a tool change and you get a hard release or stuck tool.
I have the parts except for the valve, I am thinking pneumatic tied into the spindle oil/air line. Mount this high so there is minimal distance to spindle. I need to do a series of tests as I did when originally fixing the excess oiling, it was too low air pressure @ 7 psi. Turned out to be a bad gauge. Running 14 psi seems to be the trick with this oil.
The best thing of Mobil 1 is it does not have the 'wax' residue problem of the original 68? oil.
if you are having this buildup asan issue you should run the spindle warmup program, it starts so slow specifically to engage the air/oil system, purging it for the first low rpm segment, then libricating it at the high rpm section at the latest, i say this as truely the pump will trip whenever it wants, depending on where last the gear set when deactivated. regardless it will purge the spindle and ensure one shot of lube. thats why its 20 min long as the lube cycle is 18min.
the pump rotates a gear that lifts a fork pulling the plunger up, after 18min the gear has a trip point tht releases the fork allowing the plunger to drop. due to oil pressure restrictio orifaced this drop should take 2-3 min to fully complete. this ensures all system lines are pressured and the oricafe/metering valved "should" evenly distribute the oil to all points. if the pressure drops to quickly you have an oil system leak. the haas controller measures the time it is under pressure and wlll alarm out if it does not hold pressure for longer than 2 (?) min. it will also alarm out if it holds pressure for longer than 4 (?) min as this would indicate a blocked oriface/metering valve)
the problem with vactra#2 is it will ever so slowely build up some goo and this will change the oil distrabution in the system (think a gummed up carburator) so some poits will see less lube than others. eventually it should flag an error, but this could take a year of slow buildup to hit the timer limits all the while one or more lube points are receiving less oil.
haas has come out with a service bulliten instructing owners of older machines to install a drip/sight glass on the spindle lube line so you can phisically check the quantity of lube it receives per interval, i belive its 6 drops of oil per cycle. this bulliten also recomends changing to the mobile oil instead of vactra2.
haas also recomends a spindle lube accumulation test, it involves removing the lube line from the spindle (must be the lie fed into the spindle to avoid missing any downstream leaks!. place the line in a bottle with a hole in the cap and a second breather hole in the cap. place the bottle at the same approximate height/location as where the line would enter the spindle.. run hte spindle at 20 rpm foe 2 (?) hours. measure the accumulatd oil in the bottle, it should be 1 (?) teaspoon.
its actually funny as nwer haas use a grease system to get away from potential clog issues, but they have had issues with the greas waxing up and blocking anyways, personally i prefer oil.
if yo uhave time you can pull guards and program the machine to move back and forth for a while, now you can observe the lube buildup in the ways to ensure it is even.
to save lots of time just sit at the back of the machine while its moving back and forth and lift the pump plundger several times to continually lube the system(beats waiting 20 min per shot) do this for 20 min (youll get around 6 shots in) if a way is not soaked in oil you have an impending problem
allof these service proceeedures can be found on the haas website
heres a goos reading start
Axis Lubrication System - Bijur Mechanical