[Chipload]

Grrr.... My employer VF-3 is acting strangely. The machine is 1998 vintage or so with 2-speed gearbox and 40 taper spindle. In high gear, no problem taking any cuts. The spindle load stays steady throughout a cut. In low gear, it is goofy. When cutting, the spindle load fluctuates 15% or so for no apparent reason even though the cutting parameters dose not change. Then there is times when it is really bad. The machine sometime sounds like a 4wd tractor plowing a field but it is only running 85-90% load. But if I override the machine to make the same cut in high gear, is runs smoothly. My employer says that we are to busy diagnose a problem that doesn't exist.

[haastec]

My employer says that we are to busy diagnose a problem that doesn't exist.

Then run it until it seizes, then you will be able to pinpoint the problem for your employer.

[Chipload]

My concerns have been answered. My boss started the VF-3 this mourning and it failed to change gears. He looked around checking oil levels, air pressures, solenoids, ect. and by lunch time he told me that a service tech will be out here on Friday.

[dingo0722]

Check the paramter for the max RPM for low gear. If this value is set wrong the machine will try to use the Regen brake while driving the spindle resulting in high load. Check parameter 150. For older Haas with 2 speed tran it should be set to 2439rpm.

[Chipload]

After a long delay, I am reassign to this machine. It is changing tools now. My boss said a solenoid was bad? I am not sure, did not get the full story. At any rate the spindle load is still goofy when cutting in low gear. Maybe just a annoyance. As the inserts wear, the spindle load is become more erratic when in low gear.

VF-3 Spindle load High gear - YouTube

VF-3 Spindle Load Low Gear - YouTube

[Chipload]

dingo0722, I checked parameter 150 (max rpm for low gear). It is currently set at 1829rpm, not the 2439rpm you had recommend. Is there any consequences for setting an improper number? If rpm was set extremely high such as 8000rpm or more, would it cause the spindle motor to over speed or other problems?

[haastec]

After a long delay, I am reassign to this machine. It is changing tools now. My boss said a solenoid was bad? I am not sure, did not get the full story. At any rate the spindle load is still goofy when cutting in low gear. Maybe just a annoyance. As the inserts wear, the spindle load is become more erratic when in low gear.

VF-3 Spindle load High gear - YouTube

VF-3 Spindle Load Low Gear - YouTube

It is really quite difficult to help when troubleshooting through a 3rd person and especially when you don't have all of the details.

I am not trying to harp on you, because it sounds like you care about what is going on with your machine and you are just trying to take care of issues. That said, it doesn't sound like your boss values your concerns much nor does he seem interested in taking care of things in a timely fashion.

My questions would be: Was it not changing tools initially? Was the service tech called out for only the gear change issue? Was the concern of the fluctuating load brought up to the tech at that time? If so, what was the diagnosis?

I understand that you may not have the answers to these questions, but they are important ones.

Talk to your boss about the fluctuating load. If he thinks it is a problem then he might deal with it. If not, then you have done your part and I would just run it.

Good luck!

[KenFoulks]

At that spindle speed, you may have more torque in low gear, but less horsepower to maintain that speed. Are you plunge milling? What RPM are you using?

[Chipload]

At that spindle speed, you may have more torque in low gear, but less horsepower to maintain that speed. Are you plunge milling? What RPM are you using?

Yes, that job is plunge milling S7 Tool steel. Using a 2" diameter Plunge cutter, 900rpm at 19ipm.

[glovebox20]

I do agree someting is going on.


Unforntaly, the easiest way to trouble shoot it may be to let it get worse until the machine stars breaking inserts or is inoperable.

I've seen a machine perform like this in the past and it turn out the 'Low gear' spindle windings were going bad. Too bad no one call the service tec. sooner instead of waiting until the machine was unusable to get it fixed. If the Boss thinks nothing's wrong, don't worry about until it blows up, then you can say "I told you so".