Rega Planar 2 problems

[bristone]

i have an older rega planar 2 tt (wood trim & glass platter) that i acquired through ebay last year, and it's gotten very slow lately (down to about 18rpm w/o record). i've read most of the previous symptoms & suggested remedies here at audioreview (as well as at audioasylum & ecoustics) ... JohnMichael has helped me through my first thread over in the 'vintage gear' forum (http://forums.audioreview.com/showthread.php?t=12301) & suggested i bring it here to 'analog' ... i've cleaned the pulleys, replaced the belt, cleaned & lubed the motor shaft and center hub bearing, using hypoid 90 gear oil, as suggested by Ray H in a previous thread. following this last measure, i got 33rpm for about 2 minutes, then it slowed right back down to about 16rpm this time (as the platter settled down). the motor's not making any odd noises nor does it eventually go backwards - as mentioned by some.

then i took the motor cover off from the bottom and was going to hold onto the motor while it ran (to imitate the fixed rega upgrade motor) and to see if it got better traction with the belt... well it was then that i realized that the glass platter on my tt was actually coming in contact with the top of the motor shaft pulley while it was turning. i'm pretty darn sure these are not supposed to touch, and this would explain the drastic slowdown in rpm once the platter had settled.

the bottom of my subplatter is not much more than 1 millimeter above the plinth. can someone with an operable planar 2 w/ original subplatter tell me how far down theirs sits in relation to the plinth? i did notice, when i first removed the subplatter from my tt, that the shaft had a good seal but minimal lubrication, and the single bearing fell right out when i turned over the tt. over time, could that dryness have caused the bearing to wear down the bottom of the shaft chamber, causing the subplatter to sit lower?

all is original as far as i can tell (not that i would know from any experience), but i can't see any reason why the motor shaft pulley would be too tall in this case - given it's the original planar 2 motor.

any ideas? (sorry for the length but i wanted to be thorough)
thanks ahead,
brian

[royphil345]

That's definitely the problem.

I could see the ball bearing, shaft, or chamber wearing a little over the years.

I'm not familiar with the Rega, but is there a set screw (possibly an allen head below the surface) holding the pulley on the motor shaft? If so, you could probably loosen that and slide the pulley down a millimeter or so if there's room on the subplatter for the belt to ride a little lower.

Also wondering if you might just be able to throw a slightly larger ball bearing in there without causing any problems.

It's also possible (and more likely now that I think of it, those bearings are made out of some pretty hard metal) that the wood the center bearing is attached to has sagged or changed shape a little over the years. In this case, adjusting the height of the motor pulley should do the trick. You might be able to attach the bearing assembly to the plinth using some sort of shim (not sure that would work, don't know how the bearing attaches to the plinth on that table).

Nice job experimenting with it until you figured out the problem!!! That was a tricky one. I wouldn't be surprised if you already had it fixed by the time you read this.

[JohnMichael]

i have an older rega planar 2 tt (wood trim & glass platter) that i acquired through ebay last year, and it's gotten very slow lately (down to about 18rpm w/o record). i've read most of the previous symptoms & suggested remedies here at audioreview (as well as at audioasylum & ecoustics) ... JohnMichael has helped me through my first thread over in the 'vintage gear' forum (http://forums.audioreview.com/showthread.php?t=12301) & suggested i bring it here to 'analog' ... i've cleaned the pulleys, replaced the belt, cleaned & lubed the motor shaft and center hub bearing, using hypoid 90 gear oil, as suggested by Ray H in a previous thread. following this last measure, i got 33rpm for about 2 minutes, then it slowed right back down to about 16rpm this time (as the platter settled down). the motor's not making any odd noises nor does it eventually go backwards - as mentioned by some.

then i took the motor cover off from the bottom and was going to hold onto the motor while it ran (to imitate the fixed rega upgrade motor) and to see if it got better traction with the belt... well it was then that i realized that the glass platter on my tt was actually coming in contact with the top of the motor shaft pulley while it was turning. i'm pretty darn sure these are not supposed to touch, and this would explain the drastic slowdown in rpm once the platter had settled.

the bottom of my subplatter is not much more than 1 millimeter above the plinth. can someone with an operable planar 2 w/ original subplatter tell me how far down theirs sits in relation to the plinth? i did notice, when i first removed the subplatter from my tt, that the shaft had a good seal but minimal lubrication, and the single bearing fell right out when i turned over the tt. over time, could that dryness have caused the bearing to wear down the bottom of the shaft chamber, causing the subplatter to sit lower?

all is original as far as i can tell (not that i would know from any experience), but i can't see any reason why the motor shaft pulley would be too tall in this case - given it's the original planar 2 motor.


any ideas? (sorry for the length but i wanted to be thorough)
thanks ahead,
brian

Sorry but I have not gone metric yet. My subplatter is 1/8 inch above the plinth and my glass platter is 5/8 inches from the top of the plinth to the bottom of the platter. My motor pulley is about 1/8 inch from the top of the subplatter. I am now wondering if the rubber pieces have worn out and allowed the motor to rise higher than normal. A couple of other things to look at is the bottom of the subplatter shaft and the bearing. The subplatter shaft should be flat and if it has developed a concave shape it has worn. Also the bearing should fill the bottom of the bearing well without a lot of play. The bearing housing is mounted to the plinth and there is no adjustment. I am glad you posted I would have never suspected the platter was dragging.

[royphil345]

1/8" is about 2mm. A 1mm difference in height would still give you about a 1mm clearance if your table was set up like his (his pulley clears the platter by about 1/8" or 2mm)

I still don't know if the motor pulley can be loosened on the motor shaft and slid down a bit. Still sounds like the best fix. Think if your bearing actually wore to the point where it's 1mm shorter, the sides of the bearing would be a mess also and the fit would be really sloppy. Though could be that single ball bearing in there that's worn.

Could be that the motor suspension is to blame. Don't know quite how it's mounted on the Rega. With the belt pulling between the motor and platter, I can only picture the shaft getting pulled lower due to a worn-out suspension though.

[mixadude]

OK then ;)