How to match herringbone gears?

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Grue
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How to match herringbone gears?

Postby Grue » Tue Nov 15, 2016 1:13 pm

I made two herringbone gears with the same helix, but different number of teeth. Unfortunately, they don't match. How to calculate helix pitch properly to match two gears?

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ickby
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Re: How to match herringbone gears?

Postby ickby » Tue Nov 15, 2016 1:33 pm

To get the same gradient in movement direction of the helix I think you must scale the radius and pitch in an equal manner. This means if you halfe your radius you also need to half your pitch etc.
A_3
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Re: How to match herringbone gears?

Postby A_3 » Tue Nov 15, 2016 9:40 pm

Check your gear dimension calculation, maybe something is missing.
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Mongrel_Shark
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Re: How to match herringbone gears?

Postby Mongrel_Shark » Wed Nov 16, 2016 6:00 am

Shouldn't those gears be the same thickness?
mario52
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Re: How to match herringbone gears?

Postby mario52 » Wed Nov 16, 2016 11:25 am

hi
see here tandwiel.info

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looo
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Re: How to match herringbone gears?

Postby looo » Wed Nov 16, 2016 11:59 am

I use this to compute the helix:

Code: Select all

angle=height * tan(beta) * gear_radius
auxspine = makeHelix(height * 2 * pi / abs(angle), height, 10., 0, bool(angle < 0))
beta is the angle of the cutting rack rotation.
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Gentlemanrider
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Re: How to match herringbone gears?

Postby Gentlemanrider » Thu Nov 17, 2016 3:03 pm

Just scale the helix pitch proportional to the teeth number ;)