Motor Noise on Almost New PM 3520b

[Mike Goetzke]

I did some searching but my noise seems different. A non-rhythmic (i.e. not once per rev) noise seems to be coming from the fan end of the motor. Like something loose in the fan end of the motor. I can hear it at below 500 RPM. At 500 and above the fan and other things are louder. I can hear it with the belt disconnected and the motor run or spun by hand. The motor armature spins very freely as I let it coast down without the belt. At first I though it was the fan - almost sounded like fan was loose on the shaft and hitting something every now and then. I went as far as removing the fan and the noise is still there. Since it's under warranty didn't want to tear into anything else yet. Any clues of suggestions? (This noise seemed to just start today)

Edited: After further listening it's stranger than I thought. I can hear a similar noise at the drive end of the motor but they don't seem to be in phase with each other. I was just wondering - could this just be the VFD doing it's thing? I do wear an Airshield Pro all the time so maybe I didn't notice it before.


Thanks,

Mike

[Steve Schlumpf]

No idea at this point but if you can still hear the noise when you spin the motor by hand - then that should rule out the VFD. You have removed the fan, taken the belt off and rotated the motor by hand and the noise is still there... not much left other than bearings or the possibility of something loose within the motor housing.

[Mike Goetzke]

No idea at this point but if you can still hear the noise when you spin the motor by hand - then that should rule out the VFD. You have removed the fan, taken the belt off and rotated the motor by hand and the noise is still there... not much left other than bearings or the possibility of something loose within the motor housing.

You are right Steve the noise it there even w/o power. Guess I need to give Walter Meier a call.

Mike

[Steve Schlumpf]

Seeing as how it is under warranty, I agree.

[Mike Goetzke]

Seeing as how it is under warranty, I agree.

Talked to the tech and let him listen over the phone and he said since I have a 5-year warranty to just use it for a while to see if it goes away or gets worse.

Mike

[Scott Hackler]

I would suspect a bent fan blade fin is contacting the housing. I had something very similar on an exhaust fan on a furnace. I took the cover off and looked for a fin with wear on the edge and slightly bent it until no more clicking noise. Worked great and was easy to do. Al lot easier that sending that heavy dude back for warranty work!

[Steve Schlumpf]

Scott, in his opening statement, Mike said that he went so far as to remove the fan and the noise was still there. I am thinking that there is something loose within the motor housing; debris, something that is getting thrown around when the motor is under power. Course, I haven't heard the noise... so it is just a guess on my part.

[Mike Goetzke]

Scott, in his opening statement, Mike said that he went so far as to remove the fan and the noise was still there. I am thinking that there is something loose within the motor housing; debris, something that is getting thrown around when the motor is under power. Course, I haven't heard the noise... so it is just a guess on my part.

That's what I was hoping for but I tried that. Almost sounds like a diesel engine running (but not that loud). I'm with Steve - seems like something loose (or coming loose) in the motor housing. Guess I can just ride it out since it does have another 4 years of warranty like the technician suggested but on the other hand a $4K machine should run right.

Mike

[James Combs]

Talked to the tech and let him listen over the phone and he said since I have a 5-year warranty to just use it for a while to see if it goes away or gets worse.

Mike
It would be my luck that at 5yrs+1day the motor blows up, locks up, quits or something else "now" out of warranty.:eek:

Edit: A noise like that would drive me batty over time, never liked the sound of diesels.:rolleyes:

[Thomas Canfield]

You did not mention checking the speed pick up mount. I had mine come loose and thought that there was some bearing or other problem. It turned out to be a loose set screw on the tach pickup mount to shaft.

[Mike Goetzke]

You did not mention checking the speed pick up mount. I had mine come loose and thought that there was some bearing or other problem. It turned out to be a loose set screw on the tach pickup mount to shaft.

I checked it and it in there solid.

[Steve Schlumpf]

Have you blown the motor out with compressed air? Might see or hear something in the process. Personally, I would be tempted to pull the motor and get a closer look as to what is happening. Good luck with everything!

[Mike Goetzke]

Have you blown the motor out with compressed air? Might see or hear something in the process. Personally, I would be tempted to pull the motor and get a closer look as to what is happening. Good luck with everything!

Looks like a totally enclosed motor design. I'm tempted to remove the end housing at the fan end but since it's under warranty I need to resist.

[Jack Mincey]

Try changing the tension of the belt. Had one at the school I taught that made the same sound. I thought it was the fan but ended up going away by changing the tension on the belt some. It would still come and go at times. I felt the long shaft on the motor caused it to flex when the belt was tensioned to much and cause the sound. The old 3520 has a much shorter shaft on the motor.
Jack

[Mike Goetzke]

Try changing the tension of the belt. Had one at the school I taught that made the same sound. I thought it was the fan but ended up going away by changing the tension on the belt some. It would still come and go at times. I felt the long shaft on the motor caused it to flex when the belt was tensioned to much and cause the sound. The old 3520 has a much shorter shaft on the motor.
Jack

Mine makes the noise with the belt off and rotating it by hand.

[Anthony Cayll]

My 3520 had a similar noise coming from the motor, only a few months old. Still under warranty, so I called PM and they also told me to wait to see if it gets worse or not and I told them that I paid for a properly running machine and that's what I want. So they ended up sending a tech out to my shop and found out that one of the bearings was already going bad and sent me a new motor

[Joe Kaufman]

Get a Harbor Freight Mechanic's Stethoscope - SKU 69913 - $4, remove the fan end shroud and fan run the motor and probe as close to the outer bearing race as possible. The drive end bearing is going to be difficult to get to, might have to pull the motor for electrical safety reasons. It's amazing how well the stethoscopes work in defining a problem.

[Mike Goetzke]

Get a Harbor Freight Mechanic's Stethoscope - SKU 69913 - $4, remove the fan end shroud and fan run the motor and probe as close to the outer bearing race as possible. The drive end bearing is going to be difficult to get to, might have to pull the motor for electrical safety reasons. It's amazing how well the stethoscopes work in defining a problem.

Bought one and could tell something wasn't right inside. Called PM again and they asked for video with sound. Then they requested the proof of purchase, lathe s/n, picture of the motor with label, picture of motor label cut in pieces. Today I receive the replacement motor but it doesn't have a label on it. I understand the reason to have proof that I destroyed the old label (guess so I don't resell it) but I think the new one should have had a label on it. I see on-line you can buy a replacement label for the 4224b lathe but not the 3520b. Am I being picky our should I ask about getting a label?

Thanks,

Mike

[Tim Leiter]

It can't hurt anything to ask for a label from them for your lathe. The worse that can happen is they can say "no". In my opinion. I would want one for my lathe.
Tim.

[Mike Goetzke]

Just got done swaping out the motors. No more motor noise. :D

Mike

[Randy Red Bemont]

Glad to hear that it's fixed and now quiet!

Red

[Steve Schlumpf]

Congrats Mike! Glad you were able to fix the problem! Enjoy your new 'quiet' lathe!!

[David Delo]

+1 Glad to hear your fixed up. Hate when goofy stuff like this happens. So what happens with the bad motor? Do you have to send it back?

[Pat Scott]

I would want a label too! I'd call back and request one, especially since they instructed you to destroy the old one. Glad it's fixed also.

[David C. Roseman]

Mike, glad you finally found the reason for the noise. As for the replacement motor having no label, seems to me PM is shifting risk on this to you without reasonable justification.

If you were to try to sell the lathe next year, would a buyer be concerned about it? Maybe, maybe not, but evidently PM thinks that having you destroy the label on the first motor sufficiently reduces its value that they are comfortable not having it returned. What if the replacement motor develops a problem? Now you don't have a label to cut up before PM will send you another one. :) Unlikely situations, sure, but so was the probability that the first motor would fail on an almost new lathe.

[Mike Goetzke]

Mike, glad you finally found the reason for the noise. As for the replacement motor having no label, seems to me PM is shifting risk on this to you without reasonable justification.

If you were to try to sell the lathe next year, would a buyer be concerned about it? Maybe, maybe not, but evidently PM thinks that having you destroy the label on the first motor sufficiently reduces its value that they are comfortable not having it returned. What if the replacement motor develops a problem? Now you don't have a label to cut up before PM will send you another one. :) Unlikely situations, sure, but so was the probability that the first motor would fail on an almost new lathe.

Yeah, I was first glad to get it fixed but then it's bothering me more and more that the replacement didn't have the label for both resale and I'm a hobbyist and want it to stay looking new. I emailed them and called them last Friday and they are supposed to be working on getting me a label. Hate to belabor it but now wondering if I do get a label what will be on it? The original label had a S/N and month/date of manufacture.

Mike

[Mike Goetzke]

Alright, guess I need to chuckle a little or be pi$$ed. Went out to turn a bit and even though I'm relatively new I noticed the lathe is turning the wrong way:confused:. Good thing it has reverse. They'll probably tell me to swap the FDW/REV labels.

Mike

[Peter Fabricius]

Hi Mike.
You seem to be having some issues, hope it all gets cleared up fast...
I would want a label and it should have the same info that the original had.
On the Fwd and Rev issue, your motor is wired backwards and you should get instructions from PM on how to set that straight, you should not have to mess with your control panel with a magic marker....!!!!
good luck.
Peter F.

[David C. Roseman]

Yup, sounds like it's probably wired backwards. Not a big deal, if you're comfortable switching terminals in a talk-through with PM. I'm wondering now if the unlabeled replacement motor is rebuilt. :confused: I'd ask them directly when you call. You said the lathe is almost new. I'm all for working with the equipment vendor on this type of thing, but if you just bought it recently, I don't think I'd settle for a rebuilt, especially without a label, and this new issue may be reason enough to just ask them for an RA number and a prepaid Fed Ex shipping label. If the lathe is, say, a year into the warranty, a rebuilt would probably be reasonable, IMO.

[Mike Goetzke]

Received a call today from PM tech service. This guy was sharp and knew what he was talking about. He said the motor shoud have had a name plate and he would take care of it. And I need to swap two wires on the motor to get it running in the correct direction. Now I'm ready to concentrate on turning :D.

Mike