iTopSpin

Current Posts => Collecting, Modding, Turning and Spin Science => Topic started by: jim in paris on October 25, 2013, 11:22:46 PM

Title: paper clip tops 2nd run
Post by: jim in paris on October 25, 2013, 11:22:46 PM
the video quality is really poor but it gives an idea of the fun I had making these metal wire tops
the  last one did a 55 sec sleeper !

thanx Raymond

metal wire spinning tops (http://www.youtube.com/watch?v=zObuCrYEqYM#)

jim
Title: Re: paper clip tops 2nd run
Post by: ta0 on October 26, 2013, 10:47:31 AM
 :) 

You seem to have at least two different paper clip top designs, don't you?

Answering your question, technically that cylindrical thing is a spinning top.  I liked the rattling noise it made.

PS: I had to watch it two times because the first time I was too distracted by the glasses. Do you have a collection of wacky glasses?
Title: Re: paper clip tops 2nd run
Post by: Neff on October 26, 2013, 02:37:53 PM
I like your metal head friend there Jim.
Title: Re: paper clip tops 2nd run
Post by: the Earl of Whirl on October 26, 2013, 07:12:36 PM
A collection of wacky glasses!!!  That is an interesting statement.  I have been collecting weird glasses for some time and wanted to make a display of them in my office so kids could come in there and try them on and get some laughs.  Could Jim be way ahead of me?
Title: Re: paper clip tops 2nd run
Post by: cecil on October 27, 2013, 09:03:52 PM
Mean while back at the ranch.
Title: Re: paper clip tops 2nd run
Post by: jim in paris on October 28, 2013, 02:13:51 AM
hi all !

thanx for your replies

wacky glasses : yeah i regularly buy fun glasses on street markets, and the girls also have a good collection
about the shapes , you're right  on this photo the 2 basic shapes are on the front
left is the japanese original paperclip shape
right it's raymond's improved version
both should be made with one piece of metal (no attachment no soldering)

(click)
(http://imageshack.us/a/img818/5605/u8nb.th.jpg) (http://imageshack.us/photo/my-images/818/u8nb.jpg/)

jim

Title: Re: paper clip tops 2nd run
Post by: the Earl of Whirl on January 12, 2019, 10:20:46 AM
I was looking at paper clip tops and glasses and came across this classic moment from the past.  Here is a link to specific instructions on how to make a paperclip top...

https://www.instructables.com/id/Make-A-nice-and-cheap-paperclip-top/
Title: Re: paper clip tops 2nd run
Post by: the Earl of Whirl on January 12, 2019, 10:22:10 AM
This is from the children's museum in Houston...

https://www.click2houston.com/news/science-fun-with-mr-o-paper-clip-tops
Title: Re: paper clip tops 2nd run
Post by: the Earl of Whirl on January 12, 2019, 10:25:59 AM
This is Tim at work again!  He talks about this design by a professor in Japan, Sakai?  Then he shows his design with a little magnet.  Very clever!!!

https://m.youtube.com/watch?v=qgSiMHyJcxc
Title: Re: paper clip tops 2nd run
Post by: the Earl of Whirl on January 12, 2019, 10:33:16 AM
Here is a scientific paper about paperclips and tops.  Amazingly, it includes a tippe-top made out of one big paperclip......

http://www.ucke.de/christian/physik/ftp/lectures/physics_with_clips1.pdf
Title: Re: paper clip tops 2nd run
Post by: Jeremy McCreary on January 12, 2019, 02:26:14 PM
This is Tim at work again!  He talks about this design by a professor in Japan, Sakai?

Can't seem to get the last little bit of wobble out of this LEGO Sakai top, but I'm still pretty happy with the result...

https://www.youtube.com/watch?v=X859epET9Fg

Note at 1:21 how little counterweight it takes to get decent static balance. The residual wobble is due to a combination of couple unbalance and structural flexure.

Here is a scientific paper about paperclips and tops.  Amazingly, it includes a tippe-top made out of one big paperclip......
http://www.ucke.de/christian/physik/ftp/lectures/physics_with_clips1.pdf

Great paper -- very accessible. You can also find Sakai's original paper online, but it's in Japanese.

Alas, the parts needed to make a working 3D LEGO tippe top don't yet exist, but a LEGO version of the author's 2D tippe top might just work.
Title: Re: paper clip tops 2nd run
Post by: ta0 on January 12, 2019, 04:18:24 PM
Ha, you always find a way to Legolize them!   ;D

Title: Re: paper clip tops 2nd run
Post by: Jeremy McCreary on January 12, 2019, 04:47:54 PM
Ha, you always find a way to Legolize them!   ;D

I have little choice in this. It's apparently my calling.  ???
Title: Re: paper clip tops 2nd run
Post by: Pepe on January 13, 2019, 03:10:11 PM
Here is a scientific paper about paperclips and tops.  Amazingly, it includes a tippe-top made out of one big paperclip......

http://www.ucke.de/christian/physik/ftp/lectures/physics_with_clips1.pdf

Anyone had tried the Tippie top (fig 3) mentioned in the paper??

I would love to see a video!

Title: Re: paper clip tops 2nd run
Post by: Jeremy McCreary on January 13, 2019, 07:50:37 PM
...the  last one did a 55 sec sleeper !

Never tire of watching tops that behave like that gas cartridge! I call them "gyrophonic" for the whirring sounds they make -- especially on a resonant surface.

By now have made many LEGO versions. The key ingredients appear to be...
(1) Large center of mass (CM) to contact distance relative to top's maximum diameter.
(2) Large TMI/AMI ratio, where TMI = transverse moment of inertia about the tip, and AMI = axial moment of inertia (about spin axis).
(3) Ball tip or equivalent (as in your gas cartridge).

The ball tip (3) is essential -- and within limits, the larger radius of curvature, the better. Properties (1) and (2) generally go hand-in-hand, but not always.

https://www.youtube.com/watch?v=D_btrG34M0Q
Title: Re: paper clip tops 2nd run
Post by: ta0 on January 13, 2019, 10:08:54 PM
Anyone had tried the Tippie top (fig 3) mentioned in the paper??
I would love to see a video!

(https://i.ibb.co/8461MKV/image.png)

This is equivalent to the disc with a ball top:

https://www.youtube.com/watch?v=nk1wuPBQdfA

or the reverse:

https://www.youtube.com/watch?v=h0SZZTBQmEs

Title: Re: paper clip tops 2nd run
Post by: Pepe on January 14, 2019, 02:37:29 PM
THANKS!!!

Great videos!!!