(Topic ID: 195199)

How many RPMs is a Mixer motor?

By bingopodcast

4 years ago

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  • 15 posts
  • 5 Pinsiders participating
  • Latest reply 4 years ago by Ballyoldboy
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    #1 4 years ago

    I'm trying to determine the correct number of pulses per minute on a 16 pulse switch like the select now lites. Of course this is variable based on the motor RPM, but most I've played/worked on seem to be just about the same. Math!

    What was the default config?

    I'm checking a manual now, but thought I'd check with folks here in case someone knew off the top of their head.

    #2 4 years ago

    I think I'm going to try to emulate the E-119-212 - it seems common and most will not notice an extra revolution per minute or so if there's a big range.

    The manual does not specify RPM, only part. Looking around, and not finding a lot of info yet.

    #3 4 years ago

    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.

    #4 4 years ago

    Excellent, thanks baldtwit. I do have some loose motors, but they are up in my attic and I'm lazy.

    #5 4 years ago

    I know for sure the early motors (at least up through the Bounty) ran at 19 RPM. Not sure about the later ones, but they were definitely faster. The replays racked up really fast!

    #6 4 years ago

    Night Club has a pretty fast control unit motor, but I am only concerned with the mixer.

    1 week later
    #7 4 years ago

    It will run 20% slower at 50 Hz. You have it the other way round. Living in the UK I suffer from this all the time
    Sorry the quote didn't come up from the few posts above me

    #8 4 years ago
    Quoted from Ballyoldboy:

    It will run 20% slower at 50 Hz. You have it the other way round. Living in the UK I suffer from this all the time
    Sorry the quote didn't come up from the few posts above me

    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.

    #9 4 years ago

    Very interesting baldwit, you have brought up a subject very dear to my heart. I have often wondered which lug either the 50 or 60Hz would produce less strain/heat on the coil here in the UK. Since my Bally Hawaii spotting motor went up in flames some years ago wired to the 50Hz lug I have often agonised as to weather it might not have happened if 60Hz lug had been used. Which lug produces the most resistance and would that make it run hotter in the UK due to the increased strain? (Not sure if I've made sense with that). No motor class lessons in my school we were all busy thinking about girls

    #10 4 years ago

    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 - 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.

    #11 4 years ago

    Wow thanks for that @baldwit
    I will no longer concider the 60Hz lug and stop worrying.
    It's a shame that the coil is so hard to remove thus making a rewind so difficult to do. If you have any tips to share on that I will pay great attention. I have 3 motors I would love to restore. Thanks for your time

    #12 4 years ago

    Maybe starting a motor coil removale thread would be a good idea..... but I think it's impossible

    #13 4 years ago

    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

    #14 4 years ago

    I guess it depends on whether you have it set on mix, blend, or whip! Sorry......

    #15 4 years ago
    Quoted from jrpinball:

    I guess it depends on whether you have it set on mix, blend, or whip! Sorry......

    Am I the only one who doesn't get this

    Anyway pic shows a shutter motor from my United Pixies, bingo; I bought the last one ever from PBR. I couldn't split it any further than you can see, could've saved $160, damn. No point starting new thread we all know brut force is the answer. The end

    image (resized).jpg

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