Re: RACK AND SPUR GEAR FORMULATION

--- In CAD_CAM_EDM_DRO@y..., Raul Lara <ralaco@y...> wrote:

> What's the formulation to get how many turns a Spur
> Gear need to get an inch or a foot on a Steel rack?
> I need to know a 16 Pitch Rack with a 12 No. of teeth,
> Pitch Dia. .750" Spur gear.
> And
> A 16 Pitch Rack with a 16 No. of teeth, Pitch Dia.
> 1.00" Spur gear.
> Regards
> Raul Lara
>

Gentlemen:
In answer to your questions about gear rack and distance traveled:
Two common types of rack in this country are Diametral Pitch and
Circular Pitch.

For Diametral Pitch gears,a 16 dp gear with 16 teeth has a pitchline
diameter of exactly one inch. Therefore it will travel Pi x 1 inch
per revolution along its gear rack, or 3.1415927 inches per
revolution. The distance traveled per tooth will be 3.14---/16
or .1963495 inches. For a 24 dp gear with 24 teeth, the gear rack
spacing per tooth will be 3.14---/24 = .1308997 inches.

Circular pitch gears are ideal for measuring devices such as encoders
and resolvers. A 1/10 inch circular pitch gear has a tooth spacing
along the pitch line of .100000 inches. So a 20 tooth 1/10 inch cp
gear will travel exactly 2.00000 inches per revolution. The pitchline
diameter will be 2/Pi or .6366 inches.

Metric gearing uses a "module" number.

Jack C.