iTopSpin

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Reuleaux!  (Read 806 times)

Jeremy McCreary

  • ITSA
  • Demigod member
  • **********
  • Posts: 3781
    • MOCpages
Reuleaux!
« on: July 26, 2020, 05:30:05 PM »

My latest Reuleaux top -- and a very accurate one at that!





Worried that it might not hold together well given all the outward-pointing connections. But I can twirl it fast enough for a 40 s spin time with nothing even starting to unseat!



Balance is perfect when all parts are fully seated, but most spins suffer from a slight flexure wobble.



Took this LEGO Reuleaux triangle solution from the video below by Akiyuki -- IMO, the greatest designer and builder of working LEGO machines on the planet. (But pretty sure not of this planet. Just watch some of his videos. The guy's gotta be an alien from an advanced LEGO-building civilization.)

https://youtu.be/hC0QjGbMUHI

As the video clearly shows, the Reuleaux triangle turns out to be a very special mechanical element.



My own Reuleaux top from 2015 (right) used a completely different construction method. Not as good a geometric approximation as Akiyuki's Reuleaux, but in the ballpark and much sturdier.



This one stays up ~15 s by hand and ~20 s with a ribbon-pull starter. The triangular rotor makes for some pretty cool video effects at speed...

https://www.youtube.com/watch?v=2a6UvZjsybo

Some wild effects in still photos as well...





And the top has 2 more distinct personas — one when viewed directly, and the other under a variable-speed strobe.
« Last Edit: July 26, 2020, 08:43:23 PM by Jeremy McCreary »
Logged
Art is how we decorate space, music is how we decorate time ... and with spinning tops, we decorate both.
—after Jean-Michel Basquiat, 1960-1988

Everything in the world is strange and marvelous to well-open eyes.
—Jose Ortega y Gasset, 1883-1955

ta0

  • Administrator
  • Olympus member
  • *****
  • Posts: 14235
    • www.ta0.com
Re: Reuleaux!
« Reply #1 on: July 27, 2020, 01:09:45 AM »

Nice! I like to use tops to investigate other subjects, and this is a good example of that.
However, I tried to think of an application to tops besides the shape outline and could not find one.

I had not seen before the construction at 5:00 on that video you linked.  8) It reminds me face of a clock. Somebody has to make a walk clock based on that and sell it on Etsy!  ;)
Logged

Jeremy McCreary

  • ITSA
  • Demigod member
  • **********
  • Posts: 3781
    • MOCpages
Re: Reuleaux!
« Reply #2 on: July 27, 2020, 03:43:34 AM »

Nice! I like to use tops to investigate other subjects, and this is a good example of that.

Thanks! Me, too. Tops are amazingly versatile as experimental platforms, going way beyond even the uses Maxwell put them to. And that's one of my favorite things about them.

However, I tried to think of an application to tops besides the shape outline and could not find one.

I'm drawing a blank now, too. But a voice is telling me there could be more.

I had not seen before the construction at 5:00 on that video you linked.

If you thought that was a cool mechanism, watch some of Akiyuki's other videos.

In real life, he's an industrial process engineer in Japan. And it really shows in his Rube Goldberg-like ball-handling machines, known in the LEGO biz as GBCs (great ball contraptions). Some of them are truly astounding in their mechanical creativity --- in any medium.

https://youtu.be/sUtS52lqL5w
« Last Edit: July 27, 2020, 04:20:01 AM by Jeremy McCreary »
Logged

ta0

  • Administrator
  • Olympus member
  • *****
  • Posts: 14235
    • www.ta0.com
Re: Reuleaux!
« Reply #3 on: July 27, 2020, 11:22:29 AM »

That one we had discussed before but it was nice to be amazed again! I need to look at the other Akiyuki videos.
Logged

Iacopo

  • Immortal Member
  • *********
  • Posts: 1712
    • Spin tops by Iacopo Simonelli, YouTube channel
Re: Reuleaux!
« Reply #4 on: July 27, 2020, 03:02:28 PM »

As the video clearly shows, the Reuleaux triangle turns out to be a very special mechanical element.

I have been amazed looking at that video, I didn't know the Reuleaux triangle.
Thanks for posting it, Jeremy.
Nice the Reulaeux top.
Logged