Premier Vibe Motor Conversion (Job No: 1101)

wpid-img_20140619_125711.jpg

This is a replacement motor unit made for a Premier 751 vibraphone.  The on/off switch, and potentiometer are on fly leads so that they can be fit either side of the leg hinge, on the underside of the high end transom.  The grey box contains the speed control PCB, capacitor, and various connectors, with an IEC socket fitted so that the power cable can be removed.

The motor carriage is made to fit 750 & 751 vibes, but will probably fit older models.  Like everything I make, it has been designed to overcome problems that I have had to repair many times.  This carriage is not only strong enough to actually hold the motor, but will actually stiffen the note rails and their joining piece.

Locating the pot and on/off switch to the end frame avoids the normal difficulties experienced when bowing the notes, and the leg hinge will offer protection to the components during transportation.

The grey box is the brains.  The IEC socket was a moment of realisation during conversation with the customer.  By using a standardised socket as opposed to permanently wired, prevents straining or damaging the cable which occurs when winding it around the instrument, and makes replacement simple.  In fact finding a replacement cable on a gig is now simplicity; just borrow the cable one powering the kettle, or pc, or guitar amp, etc, etc.  Additionally, there is now no need for anyone other than myself to open that grey box!  Finally, there are two small holes on the side, the small one is the power led on the PCB, the larger one is access for the trimming pot which can be used to increase the maximum speed, so can be ignored.

To fit it, six holes need to be drilled, four for the motor carriage and one each for the pot and power switch. Then its just a matter of routing the cable.

3 comments on “Premier Vibe Motor Conversion (Job No: 1101)

  1. Brian THOMAS

    Hi Paul,

    Fascinating blog as always.

    I wondered, when the motor is stopped, what is the orientation of the rotor vanes? Is it just random? Do you have some mechanism to ensure the vanes always stop in the vertical? Or doesn’t it really matter? As a non-vibist I’d have thought the optimal orientation would be vertical, and that it would be a USP to have a motor unit that could deliver that.

    Brian

    Reply
    • pauljefferies

      Hi Brian,

      Thank you for your comments.

      Having the vanes stop vertically when the motor is off has already been done. It is quite a good idea, and it does indeed greatly affect the sound projection. However, it is not really very difficult for a player to rotate the vanes by hand to the desired position. There are other associated problems of a practical nature:
      The player would have to set up the vibes with the vanes in the correct position every time.
      Expensive toothed belts and pulleys would have to be used.
      A different type of motor is needed which requires a controller as well as a driver unit which also puts the cost up.

      In my spare time and when I have the energy, which is a seemingly rare occurrence at present, I am working on programmable electronic devices. There are a few projects that I have in mind, of which this is one, that provide the opportunity for me to educate myself and fill the yawning gap in my knowledge which is electronics. However, to reiterate, my starting point is low, the subject is massive and my time and energy is finite; in other words things won’t happen fast.

      It is also interesting that from the observational, empirical and collective experience of players, that the optimal orientation of the vanes when the motor is off, is not necessarily vertical. On Premier vibes, vertical is best, whereas on Musser vibes 30-40 degrees off vertical is seemingly better.

      Paul

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *