Asymetrical Spiral Gears

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davenug
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Asymetrical Spiral Gears

Post by davenug »

Hello all,
If I construct a logarithmic gear set with a minimum pitch radius of .5 and a maximum of 1.0 (for example) then, as they start to rotate, the initial speed ratio will be 2:1, then as rotation continues it will transition through 1:1 and continue to finally end up at 1:2. Is there a way to modify the gears so that the ratio would be asymmetrical, so that the speed ration could vary from 1:1 to 1:2 through the 360 degree rotation?

Thanks,
David
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ArtF
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Re: Asymetrical Spiral Gears

Post by ArtF »

Hi David:

You may want to try the functional gears. In those you can vary the ratio over time.
The log gears are locked to that logarithmic spiral.

it begins with a list of 4 angles and the ratios for them set to 1.
Delete all the knots and enter a series of angles with the desired ratios at those angles.
The program will try to create a smooth bezier with those ratios over time for the
mating gear.

Art
davenug
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Re: Asymetrical Spiral Gears

Post by davenug »

In the functional gears, is there a way to get the logarithmic form where the two flat faces come together at the end of rotation to allow the gear set to rotate through and basically reset to the original speed ration?

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David
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ArtF
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Re: Asymetrical Spiral Gears

Post by ArtF »

David:

Sorry , no. The functional gears are derived from what's called a circular Bezier form, its math necessitated a closed form
with c2 continuous curvature.

Art
davenug
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Re: Asymetrical Spiral Gears

Post by davenug »

Is there a way to trick the logrithmic gear into doing more than 360 degrees of teeth? In 3d the gear would take a cone shape.

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David
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ArtF
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Re: Asymetrical Spiral Gears

Post by ArtF »

Dave:

Sorry, their hard coded for their angle, a defined log gear in its classical form.

Art
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