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ITSA General Assembly: December 5th - 12th

Author Topic: Inverting Tops for sale  (Read 141 times)

samb

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Inverting Tops for sale
« on: December 04, 2018, 11:56:35 AM »

I have an opportunity to provide 6061 CNC machined aluminum inverting finger top. The diameter is 1.25". I don't need to do this thru crowd funding, I just need to understand the price the community is willing to pay. I can offer as low as $27.99 with 100 orders. If less orders the price can up to triple. Any interest? Parts will be offered clear anodized, with Machine surface Ra 32 (Smooth). Image attached.

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Jeremy McCreary

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    • MOCpages
Re: Inverting Tops for sale
« Reply #1 on: December 05, 2018, 04:01:07 AM »

Have you made and tested a prototype?

The visual design is quite elegant, but in my experience, a finger top with a wide stem ( looks to be 10 mm or so) tapering downward will be hard to twirl to  high release speeds while maintaining good tilt control. The latter would necessary if the goal is to get the top to invert from a sleeping posture.
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Playing with the physical world through LEGO

samb

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Re: Inverting Tops for sale
« Reply #2 on: December 05, 2018, 10:09:56 AM »

Thanks Jermey! I’ll post a video of the working prototype when I get home later. I’ll also share the stability criteria I used to validate the design. I like your suggestion about the Handel diameter. I’m going to read through some of the posts here to learn more about that. The top I have spins quite well, but design is never complete and can always be improved!
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Jeremy McCreary

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Re: Inverting Tops for sale
« Reply #3 on: December 05, 2018, 12:37:55 PM »

We 've had several good discussions about stem diameter and shape -- especially with Iacopo. Turns out to be a lot more complicated than I expected.

My ideal diameter (for both speed and control) is about 5 mm for most tops, wider for tops with large axial moments of inertia. But I'm sure that would vary somewhat  from player to player.
« Last Edit: December 05, 2018, 12:42:39 PM by Jeremy McCreary »
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samb

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  • Posts: 15
Re: Inverting Tops for sale
« Reply #4 on: December 07, 2018, 05:37:20 PM »

Hi Guys

I'm encouraged by the number of views, I think there are people interested in these tops like I am. Here is a link to the prototype.
https://youtu.be/0ULaWVLX_mk

It works like a charm! I found I can 3D print these parts really inexpensively. You can purchase it here: http://shpws.me/JnHy

I am happy to customize it for anyone interested. Currently the handle diameter is about .42" wide. Its really comfortable in my hand. But I'd like to be involved in the community and not just sell things so feel free to request customizations.






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