Cycloidal Gear Design

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To draw cycloidal gears per B.S. 978, first choose the module (m) and teeth counts for wheel (n(w)) and pinion (n(p)). Utilize an online Gear Builder calculator like http://www.csparks.com/watchmaking/CycloidalGears/CycloidCalculator.html to obtain drawing values. Next, follow these steps: 1. Draw the wheel's pitch circle with diameter n(w)*m. 2. Draw the pinion's pitch circle tangent to the wheel's, with diameter n(p)*m and center distance (n(w)*m + n(p)*m)/2. 3. Add the addendum circle for the wheel by using a value from a table added to the wheel pitch circle. 4. Subtract the dedendum circle value from the wheel pitch circle to get the dedendum circle. 5. Draw an arc of linear dedendum on one side of the tooth from the center, with radius from the table. 6. Mirror the tooth about the centerline. For pinions with 10 or more teeth: 7. Draw the pinion's dedendum circle at a distance of 0.4*m from the wheel addendum circle. 8. Draw the centerline for a tooth at an angle without intersection with gear wheel. 9. Draw one tooth side from pinion center to pitch circle with tooth width 1.25*m at the pitch circle. 10. Complete the outline with a tangent circle arc and mirror profile to complete the tooth. For pinions with fewer than 10 teeth, refer to instructions/values on this link: http://www.csparks.com/watchmaking/CycloidalGears/index.jxl. Verify your design using the online tool at http://hessmer.org/gears/CycloidalGearBuilder.html.