***Resolved*** NEW PM-1440HVT-2 Lathe (PM fixed it)

paynerd said:
I just saw a video they attached to my email and it showed them with a micrometer and how much play is in those gears and it looks to be good.

There's not a belt tensioner on this. It has that what I'd call an idler wheel that gives it the tension. I almost want to take your bet Mr. Best but I think you're a smarter man than I am. haha. PM seemed to jump all over the VDF so I almost wonder if its a known issue. Just seems strange to think its that but after messing around in there today it almost seemed like the noise was below the headstock. It's so hard to tell. Here's my thought. They want me to run some tests to rule out the VDF. If anyone can help me do that, it will speed the process up for getting them off the VDF wagon. Here is the picture and what they wanted me to do. I downloaded the users manual and I'd need to get another college degree to figure it out.

This was one of my first emails from PM-
I am working on this with the factory, and they want to make sure that it's not a standing wave resonance issue with the VFD and motor. I'm a little skeptical that this is the solution, but we will at least rule it out. They would like to adjust the parameters on the VFD in the following way. I will just copy exactly what they're instructions are.
Please set parameter F739 to 168 and F700 to 0. This way, you can unlock and have the access for changing the parameters.

Check and set the parameters
Pt = 5
vL= motor Hz
vLv = motor voltage V
F405 = motor Kw
F415 = motor current A
F417 = motor rpm

Make sure the above parameters are correct. Please reduce the parameter of F416 between 25 ~30. If it’s not working, please change the LL parameter to motor Hz. It’s important that you record the original value of LL before changing to motor Hz. Please turn the speed to slowest and then set the parameter of F400 to 2. Then, runs the machine for about 1 min. This way, the motor is re tuning. See if this works.

If it’s not working, please change the parameter of LL to the original value.
Let me know if that does or does not help.
Thanks!
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Be skeptical - be VERY skeptical. This sounds like a fools errand to me. But you gotta step through what they ask even though a lot of the steps are hail mary's.
 
Increase the belt tension with the tension pulley, put a chuck on the spindle. These are NOT cogged belts and with cogged pulleys, they resonate at a particular frequency and the belts are jumping all over the place which they should not be doing. The plan is to see if the resonant frequency changes, if not I would think that it is something mechanical. Not familiar with the Delta VFD's but more skeptical that there is a programming tweak that would change anything. Will see.
 
davidpbest said:
Be skeptical - be VERY skeptical. This sounds like a fools errand to me. But you gotta step through what they ask even though a lot of the steps are hail mary's.
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I kind of figured that. That's what gave me the idea to ask the geniuses here on this chat to help me help them. I think this can help speed up the process. "HOPE"
 
mksj said:
Increase the belt tension with the tension pulley, put a chuck on the spindle. These are NOT cogged belts and with cogged pulleys, they resonate at a particular frequency and the belts are jumping all over the place which they should not be doing.
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Doing it now... Will report back.
 
I suggest you get PM to talk you through any VFD parameter setting they want to do. You need better support that the email, and if they get the data as the test develops they might think of other steps to take faster than an email loop. Sort of surprised PM didn't suggest that, really.
 
Winegrower said:
I suggest you get PM to talk you through any VFD parameter setting they want to do. You need better support that the email, and if they get the data as the test develops they might think of other steps to take faster than an email loop. Sort of surprised PM didn't suggest that, really.
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kind of a long story short story on this, when he sent me the instructions on what to do on the VFD I sent an email back asking more details and I got a response that was something along the lines of "what other info do you need to do this" I got pretty bothered by that and made a video showing how difficult it was to figure it out. He replied and apologized and said it was a different VFD than what he was use to .

Looks like I just got an email from PM with very detailed instructions on what to do. Must be working late hours. I like it! I'll see if I can figure it out and report back if it works.
 
paynerd said:
kind of a long story short story on this, when he sent me the instructions on what to do on the VFD I sent an email back asking more details and I got a response that was something along the lines of "what other info do you need to do this" I got pretty bothered by that and made a video showing how difficult it was to figure it out. He replied and apologized and said it was a different VFD than what he was use to .

Looks like I just got an email from PM with very detailed instructions on what to do. Must be working late hours. I like it! I'll see if I can figure it out and report back if it works.
Click to expand...
I had a call a few days ago and they seem very good guys. So don’t worry
 
The factory might be on to something, VFDs can induce torsional vibrations into the drivetrain. Changing the parameters can reduce torque ripple if it’s caused by the VFD. The motor can also have issues that cause torque pulses that could be exciting the natural frequency of the belts. Does the vibration go away at higher speeds, or does it stay bad after going through that speed range?

Changing the tension on the belts will change the natural frequency, think of tuning a piano, so by increasing the tension, the natural frequency will increase. If there is a frequency in the gear train that is exciting the belt natural frequency, increasing the tension might move that enough that is is no longer excited, or it might just change the speed at which it happens. Since it doesn’t happen when in neutral, it could be the gear mesh frequency of the gears on the spindle is causing this. Have you tried both the high and low ranges to see if this happens? I don’t recall seeing that in this thread.

VFDs usually have a setting for skipping a frequency due to natural frequency problems. That will prevent you from running at that frequency, and will accelerate quickly though it to minimize the vibrations. If you can’t find what is exciting the vibration, you might be able to operate around that frequency and avoid the problem.
 
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