Just Inherited a Mark V 500

[PeterCox]

Not yet mentioned(IIRC) is have you tried running it(squeak test) with the motor belt disconnected(motor only running)? It may be caused by motor bearings. Also does the noise change with speed setting?

Post Edited New Answers and Results

Great question.
I just tried that test and the first time the motor ran without the belt it seemed to make the same noise. So I pulled open the sheaves compressing against the spring just to look inside out of curiosity. Then I let them re-engage and started the motor again. I ran it three more times after that and didn't hear the noise at all. But then, I hooked it back up to the rest of the headstock, and the noise continued after a few seconds of running.

As far as speed goes, it seems to be worse at mid to low speeds. I notice it less at higher speeds due to the ambient noise of the motor and belts, but it's still there.

[PeterCox]

Any ideas based on my most recent findings?

[PeterCox]

I have been building a deck and had another sweet girl born. So not much time to tinker with the MarkV. JPG asked about a test. My results are above in the thread. Does anyone have any further advice for what to do next?

Thanks for the help!

[chapmanruss]

Hi Peter, welcome back,

With what you found previously it appears the sound is coming from the motor and or pulley sheaves. The easiest thing to try is lubricating the sheave again. It is possible that it could be from the motor bearing and only making the noise when there is the upward force on the motor shaft with the belt in place. That would put more work on the bearing. Just to be clear we are talking about a squealing noise and not a grinding noise.

[PeterCox]

Hi Peter, welcome back,

With what you found previously it appears the sound is coming from the motor and or pulley sheaves. The easiest thing to try is lubricating the sheave again. It is possible that it could be from the motor bearing and only making the noise when there is the upward force on the motor shaft with the belt in place. That would put more work on the bearing. Just to be clear we are talking about a squealing noise and not a grinding noise.

Thanks Russ!

It has been a while since I tried it. So lubrication is a great place to start. I will update you as soon as I give it a go. So far as I remember, it's a squealing noise and not grinding.