Turn Table Motor

[freecom64]

Hi, 

I'm a new member that has spent the last 6 months restoring a 1958 Wurlitzer 2200, Mechanically all is running well and I am presently re-buying all those old 7" records that I used to own....

The issue I am now trying to sort out is the "wow" effect when playing musically slow records.
I know the turn table speed is correct as I have made my own belt pully and physically measured the speed on it on the jukebox.
I am about to experiment with shimming the turn table with a wavy washer but was also thinking about the motor.
As this motor is approx. 51 years old, can the speed be varying? Would a motor re-wind be of any benefit?
I have already done the usual stripped and cleaned it.
I would be grateful of any thoughts?
Thanks Russ

[Ron Rich]

Hi Russ,
Have you replaced the rubber "mounts" for that motor ? Have you re-surfaced the idler wheel ? If gear driven--did you remove any/ALL old "grease" on the gears ? Did you "make" your belt out of the correct rubber--exactly correct length/width ? Motor re-winding will not fix worn out bearings--is the motor PROPERLY, lubricated -- both ends ?? What is the tracking force set at ? Is the record clamp holding the record tight to the turn-table ? Ron Rich

[e093116]

Hi Russ,

I've been through the same issue on a 2204...you can read some of my old posts here.  I managed to get it to the point where I could "live with it", but it's not as good as the Seeburgs I have in this regard.

Why did you make your own belt pulley?

Make sure you cover the basics as Ron suggests...make sure there are no old "poopies" (dried grease) in the worm gear on the motor or the plastic driven gear. Make sure the ball bearing in the end of the motor shaft is clean and not flat spotted. Disassemble the motor and make sure the internal bearing surfaces are clean and polished.  Make sure the motor shaft preload and gear mesh is "good".

I monkeyed around with the wave washer and also added automotive stick on wheel weights to the flywheel to add mass. I ended up taking some of the wheel weights off (I just stuck on the whole package I purchased around the perimeter) because it was slowing it down, or at least that was my conclusion. I think the thing that made the most difference was setting the tonearm spring pressure and tracking.

I bought a complete 2150 (other than the front glass) for $40 to use for spare parts to try another motor, plastic gear, etc. but I've decided that if I can find the front glass, I'll just restore the machine and see how it sounds.  In some aspects, it's a better "core" than the 2204...

I have a non-contact laser tachometer to check the speed, it is accurate to 1 rpm, but to "see" the problem, more resolution is needed.  I've thought about measuring the motor voltage and/or current with an oscilloscope to better see the speed fluctuation and see what effect the various adjustments cause, but haven't been able to find the time. 

Another idea instead of the wave washer would be to make a heavier flywheel out of brass or something.

Good luck with your project.

Bill

[freecom64]

Thanks for your reply’s Ron and Bill.

To answer your questions:

Ron:

The guy who I bought the jukebox off had initially started the restoration and he assured me he bought new motor mounts and belt.
Looking at them they are defiantly new, the problem I have is I can only take his word that the belt is the correct size as not having the original I don’t know its measurements. I could buy a new one I suppose.
It’s the belt pulley that fits on the motor that I have made not the actual belt. Sorry for the confusion.
When I stripped the motor I thoroughly cleaned it, I will however re-clean it when the wavy washer arrives.
The one area I have not tackled is the tone arm tracking force as at the moment I have nothing to measure it with. I have however fitted a new Cobra cartridge and have not experienced any needle jumping or sliding even on the worst distorted record.
After completely stripping and rebuilding the turn table I set and checked the record clamping force. It holds tightly. The only modification I have done in this area is the rubber record seat, I was experiencing considerable disc wobble when clamped, that was caused by the rubber seat not being flat (well worn). As you can no longer buy this item I have fitted 2 “O” rings that work perfectly and can’t be seen.

Bill:

I made a new pulley because after buying the biggest one on the net the record still ran slow.
As part of the bits and bobs that accompanied the jukebox, there was an original pulley that had been machined down to half its size. I have made and fitted a new top piece from plywood and sanded it down to size to obtain the correct speed. This was checked by putting a piece of tape on the record, mounting it on the jukebox turntable and with a stop watch counting the revolutions per minute. (Not very scientific but after a couple of runs I got reasonable consistent results).
I have read your previous thread on your 2204, hence me ordering wavy washers off ebay (it’s in the post as I type).
The one thing I have noticed is the “wow” effect is worse on the first record after the jukebox has been powered up. After an hours play it is so much better, hence my question on worn out turn table motors.
I have found a company in London that repairs vintage electric motors so I will probably give them a ring to see what their thoughts are as I have no equipment (except a multimeter) to test it with.
Regards Russ

[Ron Rich]

Hi Russ,
Did you check the suppliers in Europe for the rubber parts you "can't get" ? Sounds to me as if you have something rubber that's not made from the correct rubber--too hard-- I still don't think your motor re-wind will do any good--maybe new bearings pressed in would help ? Is the thrust bsll good ?--correctly adjusted ?? Did you use any "grease", or oil, on the nylon gears --if yes--what kinds ? Ron Rich

[freecom64]

Hi Ron.

Have to admit I haven’t checked out a European supplier for the motor mounts and belt. The one I have are the only new parts I have not bought (previous owner did this). I will check it out and prob buy new parts.
I will check out the motor when I strip it again. Good point about the thrust balls.
Have to admit again, I cleaned the motor gears on the last strip but did not lubricate them when they were rebuilt.
Should this have been done? If so what lubricant do you recommend?
Regards Russ

[Ron Rich]

Russ,
I would recommend a very small "dab", of graphite based grease on the nylon gears, and the contact area of the thrust ball. You have not indicated which oil you have used, if any ? You also have not stated your location, as requested, in our User Introduction section--If in the USA There are other suppliers other then the two you mentioned, that you might check with--see our FAQ's section. Ron Rich

[freecom64]

Hi Ron.
I will have a go with graphite grease thanks.
For those parts that I have oiled, I have used a very light weight sewing machine oil, purchased from my local craft shop.
Apologies for it not being apparent where I live, I have typed it into my profile but it hasn't appeared on my description.
I live in the Midlands in the United Kingdom, as such I have been buying parts from companies both the UK and in Europe.
Regards Russ

[Ron Rich]

Hi Russ,
Take a look at our FAQ's on "Jukebox Lubrication" -- IMHO, "light sewing machine oil" is not suitable for jukebox use--

As for the location-it shows up now--thanks

[freecom64]

Thank you for pointing out the correct lubrication Ron.
After checking it out, amazingly, 3-in-1 Electric Motor Oil is not available here in the United Kingdom. I will have to purchase it from the USA.
Regards Russ

[Ron Rich]

Russ,
Can you get the equal -- SAE 20 wt. ND oil ?
Ron Rich

[freecom64]

Hi All.
Just an update on my warble/wow sound effect.
My oldest son had a listen to the sound of the music the jukebox was putting out and straight away where is the high range volume?
After stripping out the tweeter speaker I found the cone was completely stuck rigid (have to admit this was the only speaker I never fully checked over on the re-build).
After fitting a more modern replacement bullet tweeter from a guitar amp, the difference is amazing. The sound effects have been 99% eliminated to the degree I can even now hear the record crackling during the playing of soft music!
Russ Hurt