LP12 grunt

[audiopoor]

Now with the cap and spring off, I turned it on and just as fast I turned it off in fear of damaging the motor because of the grinding sound it's now making. What is happening now????

[audiopoor]

Yes that is what the motor looks like but without the red painted seal around the cap.

[audiopoor]

Originally Posted by metaphacts

Look like this?

Do you have this tt in a jig?

[metaphacts]

Originally Posted by audiopoor

Now with the cap and spring off, I turned it on and just as fast I turned it off in fear of damaging the motor because of the grinding sound it's now making. What is happening now????

Ok should be a bushing and spring in the cap. Is there?

If so make sure the spring is straight up vertical. If not grasp it by the top and turn it in the cap until it sits straight. Take notw of the direction of the turns in the spring.

Now refit the cap on the motor and with the table sitting normally, turn on the motor. If if makes noise grasp the cup and turn it in the direction of the spring turns. Try adjusting the cup until the noise is minimized/eliminated.

Returning to one other thing, the belt should drop all the way down to the bottom of the pully when the motor first starts. If not, the motor may not be aligned properly.

[audiopoor]

I'm still working it. It one point that seemed to elimate the grunt but now all I've been able to do is soften the sound.

[audiopoor]

There has been a slight softening of the sound. But of course I want more. (well... less exactly) What exactly am I doing internally, when I 'm turning the cap? Just to be clear on what I'm doing...I'm turning the cap just a fraction at a time then turning it on, hear the grunt, turn it off, turn the cap a fraction, turn it on, listen for an improvement, if not repeat. Correct?
Yes the belt does drop all the way down when it starts up and it also slightly makes contact (rubs) in the fork shaped guide for just a second, then rises up and settles in half way up the pully. Alls good after that. No wavering in pitch, just steady as a rock.

[metaphacts]

Originally Posted by audiopoor

There has been a slight softening of the sound. But of course I want more. (well... less exactly) What exactly am I doing internally, when I 'm turning the cap? Just to be clear on what I'm doing...I'm turning the cap just a fraction at a time then turning it on, hear the grunt, turn it off, turn the cap a fraction, turn it on, listen for an improvement, if not repeat. Correct?
Yes the belt does drop all the way down when it starts up and it also slightly makes contact (rubs) in the fork shaped guide for just a second, then rises up and settles in half way up the pully. Alls good after that. No wavering in pitch, just steady as a rock.

Turning the cap is trying to relieve torque/tension on the spring so that the bushing centers properly putting even pressure on the bottom of the motor bearing. After you've done a few you can almost do it by feel as much sound. You may have to go back and forth a bit.

Sounds like your start up belt movement is correct.

[audiopoor]

Thanks so much. I'll keep trying to fine tune it.
Harv

[metaphacts]

Originally Posted by audiopoor

Thanks so much. I'll keep trying to fine tune it.
Harv

I was hoping a more recent Linn guy would chime in at some point. Sold and set up many, many, many Linns in my high end retail days - which ended 25 years ago. I'm sure there are AAers far more versed than I in current Linn lore.

[ronenash]

I think that sound is normal and is due to the high torque on the motor when its turned on. A good freind of mine has an LP12 and it behaves the same. Despite its age the LP12 is still a great table.