rubbing noise upon spindle stop from high gear

[fastfrank]

Greetings

On a 1994 VF4 I had the dreaded high gear sticky solenoid but only intermittently (my air was not dry enough). I started the machine with a power up restart, it did not shift into high gear and a 117 High gear spindle fault alarm was generated. I continued to start the machine using zero single axis and started the spindle at 200 RPM (this has helped in the past...maybe enough vibration to get the valves moving). With the spindle running for about 3 mins., a loud grinding noise was heard and the spindle was off within 2 seconds. I have since cleaned up my air and got the valves going again.

My problem/question is, now when the spindle is stopped while in high gear, a significant rubbing noise is present. Haas said they do not service motors or transmission, only replace so they didn't help. Does anyone have any thoughts or experience or do I keep running it until the problem makes itself
obvious...and expensive

Thanks

Fastfrank

[Geof]

The problem is already expensive because your only choice is replacement. My approach would be to keep on using the machine until the noise becomes completely intolerable or until everything just gives up the ghost with a big crunching sound; it might run for a very long time and if/when it does go the cost to replace it will be more or less the same as now.

[Haas__man]

ok,
So you say that you have a rubbing noise when the spindle is stopped?
If this is true then the noise isn't motor or transmission related.
Does the noise stop 2 minutes or so after you stop the spindle?
If it does then the problem could simply be that your spindle cooling fan is noisy/dirty/damaged. Also there is a gear pump that circulates oil round the transmission, this pump is usually quite noisy anyway. Is it noisy when the spindle runs in high or low gear too?

[fastfrank]

Greetings

Sorry, I wasn't as clear as I should have been. The noise is present while the spindle is stopping under deceleration. It is loud enough it makes me grit my teeth and pucker up. Common sense is telling me it is loud enough it is not going to heal on its own. Once inside the trans, I would think it would be something minor. I can't help but wonder, what is the magic that only Haas can capture when taking the motor/tranny apart. The balance of the assembly is probably quite important but that is already established, as long as the indexing is maintained on reassembly, that should be fine. Maybe it is special tools or fixtures or heavy press fits. Everything mechanical is just nuts and bolts but it is the experience that brings the important dos and don'ts to light...which I don't have with this unit.

[MrWild]

Dpes it sound like a car with worn out brakes? Could be as simple as the spindle brake pad wore away or fell off.

[Haas__man]

There are no brake pads or anything to do with braking that can 'wear'
If you orientate the spindle does it always stop in the correct position or does it change?
Could be the spindle drive belts that have teeth missing maybe?
does it make the noise in both gears? or just one?

[fastfrank]

Greetings Haas-man

I really haven't been orienting the spindle a lot since the grind. Most of my work is at 6000 RPM and I haven't worked up the nerve to run it yet, so I have just been turning the spindle off and on manually. What little I have oriented it, it has been correct.

I checked the belts and all is OK.

It makes the most noise in high gear. The amount of noise it makes in low gear, I could easily live with even at 1750 RPM (the motor is running almost wide open)or so...but not in high.

I have all the covers off and have the spindle turning on and off in a loop at 2500 RPM with a 3 second dwell in between. As I try to pinpoint the noise, it sounds like it is just under the encoder drive shaft that comes out of the gear box just behind the motor. I made sure the shot pin that orients the spindle on that shaft was not rubbing. If I use a stethoscope, I hear rubbing followed by some ticking just before rotation stops. I have now cycled the spindle over 200 times, and the noise hasn't gotten worse or better.

[tizm]

I dont know too much about haas but the haas pallet-changer at my shop doent have a transmission,its a belt-driven spindle! if yours is also,it could be worn belts!