Wednesday, September 25, 2013

Fixing the governor

As a gramophone owner you were expected to regularly take the thing apart and oil it. Or maybe expected to take it up to your gramophone shop and have it serviced. The instruction leaflet that came with such machines does include the steps to take out the motor-board ("grasp edge of horn by left hand, grasp winding key by right hand and lift out motor board").

Once you have the motor board out, you can see the lubrication chart that is glued to the bottom of the case. ("oil according to greasing chart to be found below motor").

Now there's a thought for typewriters. The service chart could be in the lid or cover and right there when the mechanism is opened up. (Maybe some machines did have that, I do not know...)

Because the turntable did not keep a stable speed and make a rather loud chugging noise, the friction pad in the governor was the first suspect. If that has gone 'solid', there would not be a large stable rpm range and any un-evenness would give a chugging sound like a steam locomotive at speed.

With an additional four screws loosened, the motor indeed gently drops out of the board. The motor is heavy, most of the weight of the whole gramophone is the motor. The plates and pillars are dimensioned generously, then again it does need to safely contain a strong spring with a lot of energy in it.

The little friction pad had indeed taken the consistency of a small stone. Hard like a little rock. After first trying to soften it up and re-oil it, it was decided to replace it. Gently prying open the clamps holding the leather the 'stone' dropped out. Stacking two small pads cut to size (old leather belt), these were clamped tight again in the friction pad holder and then provided with several generous doses of machine oil. This made the new pad soaked and fit for service.

Putting the machine together to try, it now runs at a stable speed. The pitch regulator now actually governs the speed where first it was more of a switch from 'stop' to 'as fast as you can'. The chugging sound was also mostly gone. As the new leather pad settles in, this is gradually becoming less.

Also had to oil and work the sliding bush of the governor with the friction disc. It moves now, but a bit sluggish. This makes it slow to reach stable speed but otherwise has no ill effect.

Now to fine-tune and re-adjust the pitch regulator, perhaps to print a strobe disc.

Like the typewriters also very mechanical, but definitely on a different scale. Different both in size of the components and in the complexity of the mechanisms.

An enjoyable excursion :)


  1. Good work. That is an intriguing little motor.

  2. That looks fun to play with and listen to.

  3. It is indeed neat to tinker with :)
    Not half as complex as a tw though and much bigger. Not little at all!
    (And much louder...)

  4. hi,
    can you give me a hint on how to remove the turntable?
    i have a HMV model 101, and there is something wrong with the motor, but i can not remove the turntabe, so that i could see the top of the motor.

    1. That should lift off after sliding off the small clip on the spindle. If stuck, a very gentle tap on the spindle whilst pulling up the turntable can do the trick.
      Do see my July 2014 post on greasing the HMV101 motor.
      Good luck! Grand instruments :)

  5. thanks Robert!
    i don't have the clip on the spindle, so first tried with a rubber hammer with no luck, but with a metal one managed to remove the turntable:)
    unfortunately the spring is broken in the motor... will have to find a new one somewhere.

    1. Hope you can fix it up - luckily springs can be had still; I've bought from Will also likely sell a new circlip.
      (Oh, and some light oil left overnight can do wonders for stuck parts...)

  6. After purchasing a non working gramophone (mead) I found your post very interesting. I am especially interested in the speed governor friction pad that uou made from a belt. The pads in my machine look more like old pieces of cotton wool and most certainly do not make any difference to regulating the speed of the turntable. Is there somewhere youcan purchase the pads or is the best option to DIY? Thanks Lisa

    1. Congrats! That's a store brand I think. Probably a Swiss-bought motor - may be slightly different governor design.
      Key to all friction governors working is that the friction pad that is pressed onto the brass disk is resilient. It must deform a bit under pressure. If it's rock-hard, then the governor will be unstable (only fast or stopped).
      Not sure pads are sold (springs are though). If it's not leather but fabric I'd try dense felt or similar. (And oil.)
      Good luck! Hope you get it fixed - grams have great sound :-)