Why engineers refuse to design gears with fewer than 17 teeth

This absolutely wrong, a gear can have fewer than 17 teeth. Gear teeth follow a standard that's based off of the Pitch and Pressure Angle of the gear, basically the interface diameter of the teeth. That determines the depth and shape of the Tooth.

lead machinist here for one of the largest gear manufacturers. we make gears with fewer than 17 teeth literally all the time.

For low load applications, you can, but for higher loads, fewer number of teeth means more pressure and by extension increased wear and shorter life

Many automotive pinion gears have less than 17 teeth. Look at 5.29:1 Ford 9” for 1 example.

Wrong, very wrong. Engagement farm much? Muted.

Never I’ll make you a 9tooth gear on every machine you see in this video.

Engagement farming…it’s what all the teeth are for.

There are thousands of gears made with less than 17 teeth. If you are referring to a specific application then there could be restrictions due to power requirements.

The flywheel engagement gear on my tractor starter has 9 teeth. I just had to replace the starter and that is a critical number to know for the new starter.

Total misinformation. 9-37 is a common ring and pinion pairing. I’d say it was designed by an engineer, but AI as usual is shooting its mouth off before it knows what it’s talking about…

Bmw diff ratios and gear teeth numbers (in brackets) Small cases : 168mm H7 = 2.79  ( 39:14 ) H17 = 3.38  ( 44:13 ) H41 = 3.45  ( 38:11 ) H9 = 3.64 H2 = 3.91  ( 43:11 ) H1 = 4.10  ( 41: 10 ) H8 = 4.27  ( 47:11 ) H12 = 4.44  ( 40:9 )

Somebody is gonna have to dumb this down for me, because I don't get it. Especially the sharp pencil analogy.

Hyperbolic gear tooth contact surfaces are too distorted, interfere and don't work.

Otherwise you will end up with undercuts, eventually with no tooth left, duuuh. Unless you increase the pressure angle but then you will have vibration/noise issues, thus wear and less overall life

A post that long about gear teeth without once mentioning the words involute or helical is just going out of it’s way NOT to explain things ….

Maintain engagement

Prime numbers are good.

It's an arbitrary limit set by engineers for the aforementioned reasons AND (not mentioned in the video), because of the change in angles from initial incidence to perpendicular. When that angle becomes too steep, the teeth push more separating than driving. Inefficient.

👍🏻

Chevy starters come in 9 tooth and 11 tooth pinion gears versions.

Fantastic information

Says who?

This is stupid. The smallest cog on my bike's cassette has 11 teeth. Some have 10.

Erase ur account, or at least change the name on it 🙄