How not to drive your turntable

To recap of where we are:

  • The gears started spinning on their shafts because the shafts are round, and well, there is too much torque to overcome in the lazy susan.
  • To overcome the spinning problem, I drilled and pinned the gears to their shafts.
  • Then the whole mechanism had stiff spots, but kind of worked.
  • I reasoned that the output shaft from the gearbox was not perfectly aligned with the input shaft for the turntable.

To accommodate this last failing, I designed and built a sloppy connector between the two shafts.  This was based on telescoping square tube, cut into T shapes and soldered together.

Turntable couplingTurntable coupling

Unfortunately, while testing the coupling, the pin holding the worm gear (not the worm) to its shaft bent and actually pulled out!  Seriously!  How much torque can I need to drive this turntable?  On closer inspection, it appears that my pin actually goes through a channel I drilled through the shaft, rather than a hole.

I re-pinned the gear, but the inside seems to be stripped, and even though the pin was fixed at both ends, there is enough room in there somehow that the gear turns freely.

I’m about ready to give up on the Tamiya gears in my homemade gearbox.  Anyone know of any low-cost, but relatively beefy worm reducers?  A quick search on the web yields all sorts of expensive-looking options…

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4 thoughts on “How not to drive your turntable

    1. Thanks Simon. It looks like the output shaft is round on this too. However, it is interesting that there is no gearbox per se in their design. Any eccentricity is taken up in the mesh of the gears. There’s some food for thought.

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