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Push / Pull spinner from VCR parts

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krutknut:
I'm in the mood for a game of Discs of Tron, so I will attempt to build a push / pull spinner from a VCR head drum. I have two drums that would probably both work.

The "pull" part is trivial if I accept some friction during the pull, the problem I consider is how to get the push part working without friction during a normal spin.

edit: I do not want added friction during push or pull and I do not want the spinner to wobble either.

krutknut:
As you see, the I have removed the ring that bolts the two parts of the drum together.


In the second image, you see that the bearings sit on the smaller lighter well-balanced part of the drum. The other part, with the shaft is a bit unbalanced on the three drums that I have.



The smaller part can be pushed and pulled up and down on the shaft without any wobble. So, a push / pull spinner should be possible to build.

The question is, how to place the microswitches for the buttons to achieve as little friction as possible?

krutknut:
That wasn't so hard to solve. At least not the principle. The implementation might be harder. Or not...

If I place a spring between the two parts, then I can press down / pull up without any friction affecting the spin at all, since the spring rests on the part of the bearing that clings to the shaft. I just need to extend something out from the spring, so that the switches can be pressed at the up/down motion. I also need a shorter spring, because this one makes the shaft too short. Or, I could get a longer shaft. Maybe I will get rid of the lower part, since the only thing it contributes with is the shaft.

The technique will probably be similar to the Blackhawk spinner, using a disc that sticks out to push the up down buttons. Except that in this much simpler spinner, the push / pull motion will not cause any extra friction that can damage the switches (I do not have any special microswitches that are extra resistant to damage). Because the disc that pushes the up down buttons will not spin.

What do you people think?

Major Rock Hardy:
I can't tell if your design has a moving shaft (that is, up and down) or if the shaft stays put (vertically speaking).  If the shaft moves, see the below pics of an original DOT spinner (not mine) for some ideas, namely:

You could do a similar thing that Williams did (see the Spinner02 image) whereby you stick two pieces of spring steel (the metal banding they use at lumber yards would probably work - this was an idea I had for when I get to my DOT spinner project) with holes drilled in them for the shaft.  Those two pieces could go on opposite sides of your little brass setscrew-donut thing (in place of the white plastic disk in the original spinner) and act as arms that contact either microswitches or leaf switches when the shaft moves up and down.

clear as mud?  :)  Sometimes I don't know if I explain my ideas well enough.

krutknut:
There are actually two shafts in the design I consider. There is a lower shaft, where the spinning VCR head can move up and down. On the picture, a lower spring is in place, which creates a push spinner. To create a pull spinner, the spring should be above. Both above and below creates a push / pull spinner. The springs rests on the edge of the bearings, and so they cause no extra friction. In a VCR head, the head rests on the edge of the bearings anyway, both on the lower VCR head part and on the top brass ring.

Then there is also a top shaft, attached to the VCR head. This shaft goes up to the spinner knob. Using this shaft one pushes and pulls the VCR head along the lower shaft. There are holes in the VCR head that can be used to attach the top shaft. Unless I do this in a bad way, there will be no wobble in this spinner, because the VCR head does not wobble on the lower shaft as it spins.

Why are there two shafts? Well, that is only because in the VCR heads I happen to have, the wheel with the bearings is balanced, whereas the lower part with the shaft is unbalanced. If the lower part was balanced as well, then one shaft would do the trick.

So both the Williams design that you present, and the Blackhawk design might work... those images got me something to think about.

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