this is from memory, so be concerned ...

depends on the game/motor. The multiproducts and probably merkle motors were 19 rpm. Some of the late model molon motors were 23 rpm, and would run at 25 in countries with 50Hz power.

the rpm is stamped on some of the gearboxes if you have some loose motors to look at.

yes, that was wrong. It was a different motor part number that ran at 25 rpm. There's three main documented rpms of mixer/CU shaded pole motors:

1] the earlier motors with only two lugs on the stator winding ran 19 rpm at 60Hz. Those will run slower and hotter at 50Hz

2] later motors with three lugs on the windings - common, 50Hz and 60Hz. Like E-119-462 and E-119-359

Keeping in mind I mostly ignored my motors class in school, one possibility is the different lugs will alter the magnetic field strength and the "slip" of the rotor in the field, allowing the speed to stay about the same at 50 or 60Hz. Since slip would be dependent on torque requirements (resistance to shaft turning due to clutches and switch lifting), that would kinda explain why there's different motor part numbers for different games/game types.

Or the lugs are just for managing the power and the motor runs around 23.4 rpm at 60Hz and 18.7 rpm at 50Hz.

Got a machine with 50Hz lugs and want to estimate the rpm? ... or know someone who didn't skip all but two of their motor class lectures?

3] the E-119-370 motor was 25 RPM, 50Hz only and sometimes says "Belgium" in the manuals.

anyway, the motors mostly ran at 19 RPM, but some ran at 23 or 25. Afaik, the faster motors were just on games well after Bounty.

Bounty has two motors in the manual - E-119-212 (60Hz) and E-119-234 (50Hz). The only difference is the stator....I assume the length of wire in the winding.

okay, all the below is probably wrong, but fwiw....

short answer is I think the 60Hz lug -> common lug wire length is shorter (the 60Hz lug is connected partway along the length of the winding).

it's not really a resistance thing tho, it has to do with the rotating magnetic field/flux being generated in the stator and how the rotor responds to it. Probably best to google how a shaded pole induction motor works...it may help to look up "squirrel cage rotor" as well.

the equation is:

E=4.44fNM

where:
E - sinusoidal (A/C) voltage
f - frequency
N - number of turns of wire around the stator
M - Maximum flux density the stator can handle ... it's a property of the metal and the way it's constructed

if ya assume the voltage is constant at 120V and the desired flux density is constant, then a decrease in frequency needs an increase in turns of wire to keep the equation balanced.

if you don't have a multiple tap winding, when you lower the frequency you must be increasing the flux toward the saturation point and the current will increase ... along with the heat. Compound that with the fan spinning at a lower rpm and you've got a problem if the motor wasn't designed for it.

so if you have a 50Hz connection, use it. It'll reduce the heat. Your Hawaii motor should have cooked faster on the 60Hz tap. The reason the thing fried to begin with is usually the shaft components are cruddy and the torque required to turn them goes up. There's more formulas, but as you'd expect more torque = more power = more current = more heat.

I suppose if you don't want to get a good explanation elsewhere, you may be wondering how current snuck into all this since it's not obviously in the formula above. It's hidden in the M term. Flux is generated when a current flows through a wire....or when flux is present, current is generated in a wire. It's kinda the linkage between electricity and magnetism.

so who wants to measure the resistance of the motor winding and shoot all that down? You could also just look and see if the 60Hz lug has a double winding wire on it (it's in the middle of a daisy-chain) and the other two have just a single wire.

for rewinding the coil, there's at least three styles of stators:
- coil around a bow-tie section that is pressed in...like a dovetail joint
- coil around a "cap" section like in the picture
- no obvious joints

the second one is the most likely to pop apart. The first one I tried a 20 ton press on and basically destroyed the parts getting them separated. It may be easier to drill out the rivets and unstack the laminations...if they will come apart. If they were coated with something, the heat may have glued them together.

what I didn't try and should have is heating the joint to expand the metal.

a guy in the UK had one that came apart with a few taps of a hammer.

take a pic of one you have and then try heating the joint. If that doesn't work, are the laminations riveted?

a new thread may be better.

Fractional-Motor-Cores (resized).jpg