## How to match herringbone gears?

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Grue
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### How to match herringbone gears?

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
Posts: 2940
Joined: Wed Oct 05, 2011 7:36 am

### Re: How to match herringbone gears?

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
Posts: 81
Joined: Wed Jan 20, 2016 9:13 pm

### Re: How to match herringbone gears?

Check your gear dimension calculation, maybe something is missing.
Mongrel_Shark
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Location: Australia

### Re: How to match herringbone gears?

Shouldn't those gears be the same thickness?
mario52
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Joined: Wed May 16, 2012 2:13 pm

### Re: How to match herringbone gears?

hi
see here tandwiel.info

mario
Maybe you need a special feature, go into Macros_recipes and Code_snippets, Dialog creation. My macros on Gist.github.
looo
Posts: 3190
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### Re: How to match herringbone gears?

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.