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[ta0]

Somebody 3D printed a pump top, including the clutch and torsion springs. The only non 3D printed parts are screws.



The instructions and stl files are here: http://www.otvinta.com/download15.html

I'll probably print one in the future.

[ta0]

Another one. The top is not as nice, but the video has a detailed explanation of the design:



The files in Thingiverse:

https://www.thingiverse.com/thing:3822746

[Jeremy McCreary]

Just found this LEGO pump top by a well-known and very clever Japanese builder:



He's written several books full of ingenious LEGO mechanisms and whimsical machines. My kind of guy.

This one could easily be improved by lowering the CM and doubling the yellow flywheel ring.

My own attempts at a LEGO pump top all failed for lack of a suitable screw, LEGO or otherwise. Looks like LEGO now makes the screw. Off to www.bricklink.com ....

[ta0]

Nice!

I'm guessing the elastic bands to pull up the screw are there because the top is too light for the friction of the screw and you would lift the top if you just pull up. But this has the disadvantage that the resting position is with the screw up what raises the center of mass (although you could argue a tall top looks more elegant).

[ortwin]

...  Looks like LEGO now makes the screw. Off to www.bricklink.com ....

Great Jeremy! This topic reminds me of the topic where we discussed gravity powered tops and some  ideas that remained just ideas at the time. So Jeremy, once you have that screw and you build a top similar to the one in the video, I also want you to consider a version that accelerates the top not when the handle is pushed down, but when the top is lifted by the handle (similar to this video) but with that clever mechanism so you can do it repeatedly. I imagine that principle to be a good way to start really  big tops.

[Jeremy McCreary]

Great Jeremy! This topic reminds me of the topic where we discussed gravity powered tops and some  ideas that remained just ideas at the time. So Jeremy, once you have that screw and you build a top similar to the one in the video, I also want you to consider a version that accelerates the top not when the handle is pushed down, but when the top is lifted by the handle (similar to this video) but with that clever mechanism so you can do it repeatedly. I imagine that principle to be a good way to start really  big tops.

Worth a try for my 2nd gravity-driven top. As you may recall, here's my first:

[ortwin]

...
Worth a try for my 2nd gravity-driven top. As you may recall, here's my first:

Yes, I recall that gravity-driven top. But it was not your only one. Here you show a photo of another one.


And another "But": "But are not all tops gravity driven?" I mean if you trace back the energy form you supply a top with, you always end up with gravity. Or do you have a different view on that?

[Jeremy McCreary]

Yes, I recall that gravity-driven top. But it was not your only one. Here you show a photo of another one.

And another "But": "But are not all tops gravity driven?" I mean if you trace back the energy form you supply a top with, you always end up with gravity. Or do you have a different view on that?

Wow, your memory's better than mine! Alas, never got that one to release the top properly.

Had to think about the gravity question. In the end, feels too contrived.

[ortwin]

...
Had to think about the gravity question. In the end, feels too contrived.

Had to look up the word "contrived". In the end, feels you are right.


(Do you ever get sentimental when you see the kitchen in your former house in those videos?)