Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Jeremy McCreary]

Many of us use strings to spin tops. But what about spinning the strings themselves?



You can see the device itself at 11:10. See video description for details.

[the Earl of Whirl]

Wow!  Quite interesting.  "Trippy" is right.

[ta0]

Fantastic! I love it! 

Changing the span by changing the arm angle is mechanical genius.
It would be nice to be able to also adjust the phase in real time. But it's a bit complicated mechanically.
It could also be interesting to switch the rotation direction of one with respect to the other . . .

[Jeremy McCreary]

Fantastic! I love it! 

Changing the span by changing the arm angle is mechanical genius.
It would be nice to be able to also adjust the phase in real time. But it's a bit complicated mechanically.
It could also be interesting to switch the rotation direction of one with respect to the other . . .

Thanks! Given that much of modern physics is based on standing waves of one kind or another, thought you might get a kick out of this.

Would love to have phase adjustment on the fly. Not entirely out of the question, either. But as you said, the drivelines would get a lot more complicated. And that would mean less delivered power and torque at the string mounts.

The good news: A phase change takes 10 seconds.

For this to work at all, the string mounts must spin in the same direction at exactly the same speed. Otherwise, the string winds up or unravels. Hence one motor turning 2 identical drivelines.

[ta0]

For this to work at all, the string mounts must spin in the same direction at exactly the same speed. Otherwise, the string winds up or unravels. Hence one motor turning 2 identical drivelines.

Yes, of course 
Unless you put a swivel in the middle of the string.

[Jeremy McCreary]

For this to work at all, the string mounts must spin in the same direction at exactly the same speed. Otherwise, the string winds up or unravels. Hence one motor turning 2 identical drivelines.

Yes, of course 
Unless you put a swivel in the middle of the string.

Hmmm, visions of fishing line swivels dancing in my head now.

[Jeremy McCreary]

A fancy high-tech version of the  wavinator recently appeared (and apparently failed) on Kickstarter at a projected $340 retail.

https://www.kickstarter.com/projects/northerncircuitsinc/string-of-pisces/description?lang=de

Love their string lighting approach with the phased RGB LEDs. Largely makes up for the limited number of attainable modes -- a direct consequence of having only 1 string and 1 string contol (speed). Span and free string length are fixed.

[Pepe]

Im loving this sooo much!!!

Im dreaming of one stage size for a performance WOWOW

[Jeremy McCreary]

Im dreaming of one stage size for a performance

The dynamic depends on several nondimensional ratios like (span) / (free rope length). So it should scale up with the right rope weight.

The main engineering challenge: Rope ends must spin at exactly the same speed.

[Jeremy McCreary]

Speaking of standing waves...

Ecola Creek hosting 2 standing wave systems side by side as it cuts across the beach bar at low tide in Cannon Beach, OR after last night's rain. The nearer wave system has the longer average wavelength.