Turntable wheel drive looks successful

I think Mark Dance’s idea of driving this turntable with a wheel riding out near the edge of the table is going to work!

Rather than dig into the Lego for real, I made my own wheel from some O-rings and brass and 1/2″ styrene tube. The 1/2″ wheel yields about nine turns for a full 360 degrees – some work, but not enough to be really truly annoying. As you can see, the wheel sits in a recess in the plywood half-cover for the turntable that also supports the current collectors and that used to support the worm drive.

To spin the wheel, I jammed a piece of a turnout actuating rod into the end of the wheel’s axle. This should enable me to thread the drive through the maze of benchwork here at the edge of the railroad much easier than a pukka set of universal joints. It isn’t a long run, but I’ll certainly want to test it before declaring final victory.

From below, the drive wheel peeks out through a square hole in the turntable cover. Sadly, I didn’t get to complete the testing because the nuts I picked up at Rona this afternoon on the way home turned out to be 6-32, not 8-32 as I thought when I grabbed the package.

Wheel drive for turntable

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4 thoughts on “Turntable wheel drive looks successful

  1. This is just a neat project to follow along with. I wish I had something to contribute to the thread beyond my expression.

    The build is of a nature that feels so completely in line with the era you’re modeling and a celebration of a more mechanical approach.

    Thanks

    /chris

  2. Hi Rene,

    I’m not connected to most of the services that allow one to comment directly on your blog, so thought I’d send an e-mail.

    I’ve enjoyed watching this project develop through all the ups and downs. Your persistence and ingenuity are inspiring. Between the turntable and the engine house doors, some elegant animation that will add to the layout!

    I’m wondering if you are considering doing anything to make precise track alignment easier, or will it depend on the eyes of the turntable operator? I guess one approach would be another small wheel on the edge of the support material and several small v notches cut in adjacent material so the wheel could nest positively when each track is aligned.

    Rob Kirkham

    1. Hi Rob, Nice to hear from you. Yes, as with the staging turntable, there will be a positive indexing pin. On a real turntable, there is a locking mechanism, and driving the pin into its receptacle is going to be the physical equivalent on the model. A happy outcome of using a wheel drive instead of a worm is that it can be driven both ways. So a tapered pin should be able to move the turntable into “perfect” alignment.

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