Bad 50hz Conversion?

Ron Rich wrote:Doghouse,
I would assume, "someone" made these up for dual speed use, and also sold it for single speed use ?
Ron Rich

Hmm.

Possibly but it looks like a bit of quite sophisticated engineering, requiring a lathe that could produce something to quite fine tolerances. Would it be a factory produced part, (apart from the "big screw") to allow for the difference between 60 and 50 cycles as this machine was destined for the UK?

Well, I've know tried a few "conversion" springs from a few vendors and still the speed is too slow.

So, either I've been given the wrong springs (I doubt it), my tt motor has been replaced with one from another model, or the motor is running slower.

The motor speed seems consistent, just overall slower. Could a worn out or gummed up motor cause this issue? Should I consider taking it out and opening up to clean and re-oil?

I've already added some 3 in 1 motor oil to both spouts with no change

How are you "checking" the speed ? Has "someone" "adjusted" the idler wheel, spring tension ? Are the idler wheel, and TT, clean ?
Is the idler wheel "glazed" ? Are the rubber motor mounts good, and correct ? Did you give the oil time to get to the motor bearing--did you oil the TT ?
Ron Rich

Hi Ron,

This has been tinkered with before. As you stated in an earlier post someone put a heavy duty spring on the idler to compensate for a dent that looks to have happened when the jukebox sat in storage for years. So I've replaced this with a proper spring from a reputable jukebox parts store, along with a new repro idler wheel. I also cleaned the rim of the deck with alcohol. The speed I judged from my ears, but then verified with a strobe disk. If anything I'd expect a jukebox to run fast, more songs = more money! Also better on the ears

The motor grommets have been replaced, and the TT bearing already seems well oiled - this machine was well and truly gepetto-ed before it reached me, oil everywhere!

I just added more oil to the motor tonight but didn't wait too long I guess..

When I got the machine the speed was fine but the spring fitted was thicker than any I've bought online and was bent out of shape and causing lots of noise to the turntable. The noise is gone now but I'm left with slow speed. It's not horrendously slow, but enough so it takes the life out of some songs...I'm wondering whether to buy a frequency converter or strip the motor down and re-oil, at the cost of buying a pure sine wave converter I may as we'll replace the motor!! Man, this machine is proving a struggle!

Does the rotor coast when power is turned off and the puck is held away. Those aren't the quality of motor that you find in a good turntable (Dual etc) but it should coast a for a few seconds. Does the speed remain slow even after it has warmed up? IF you grip the shaft with two finger, does it feel free?

Given the neglect and poor treatment these machines often get, it is possible that another motor has been subbed at some point and the one now resident was designed for a slightly smaller diameter T-T.

If all else fails there is the old radio station trick of wrapping thin tape around the shaft to widen it. The shaft must be cleaned with alcohol and we....I mean they..used editing tape for it's thin-ness. Apply a bit too much and unwind-cutoff enough to get the speed you desire.

Rob/NYC

It does feel free to rotate by hand, but then I dont know what a good one is like. When I stop it it will spin for between 1 and 2 seconds when the idler is away from it.

PTFE tape isnt a bad idea. I've managed to get the speed right, but I do have some of the same rumble now that I had originally. I guess its quite hard to make it completely uniform as you wrap the tape round. I'll experiment some more I guess.

Is there any merit to removing the motor anwyay and dismantling to clean and re-oil? Will the motor drop out under the deck if I remove the c-clips from the grometts?

Hi
The motor is pretty easy to remove, just watch you don't lose the c clips and brass spaces. I would unplug the motor and remove the turntable assembly, easier to work at when removed, the motor can be removed without letting it drop, the motor can be taken apart usually 4 screws or bolts. Any old rockola turntable motor i come across always needs cleaning and lubrication. When you have the turntable assembly off make sure it hasn't been damaged or bent this may cause a speed problem
clones

A customer of ours described what he did on his slow 453 - incl. cleaning and lubricating the TT motor.
http://www.jukebox-world.de/Forum/Archi ... %20langsam.

Using an automatic translator should give a clue about it (unless one wants to learn some German in advance ).

Hildegard

I did study German at school, a fantastic sounding language, but I'm ashamed to say I have forgotten most of it

I will take a look, many thanks Hildegard and everyone else. I'll update when I've had a go and will try and document with pictures

Well, I took the motor apart to clean it, didnt seem too bad really but I thought a soak in solvent wouldnt hurt.

Unfortunately I may well have knackered the motor !

I guess the solvent I was using killed some glue that was holding part of the armature on!

See below, I can see where the glue was so I guess I could glue it back on, but I'm guessing I couldnt get it accurate enough? May well turn out to be the best solution anyhow, as this doesnt appear to be the correct motor for my jukebox judging by the part number.






Is this salvageable? Or have a finished this motor off

The motor part number I have is 3583502

The parts catalogue lists 400912-A , Interestingly there is also a 50hz version listed (403102-A)! I guess this would be the 60hz model, with a spring already fitted


Either way the part number on my motor would suggest it came from an earlier model? As Rob says, potentially intended to work with a slightly different sized turntable

Hi
Its happened before with myself. I just stuck it back in with superglue
Clones

Hi Guys,
It has been my experience that "super glues" won't hold metal to metal for any amount of time. I prefer to use an epoxy type for something of this nature--Ron Rich