# Helical Planetary Gear

Helical Planetary gear can look complicated in designing but believe me it's as simple as designing normal gear .

Planetary gear seems to be very complicated while designing in any cad software like Fusion 360 , SolidWorks etc. But this tutorial is very easy way to make Planetary gear with wide range of gear ratio provided you should have basic knowledge about gear ratio ,gear physics .

This tutorial is for fusion 360 Beginners and intermediate .

Here you can learn some tricks while learning design .

3. ### Step 3: Ring gear

To make ring gear

• Add spur gear of 96 teeth , modulus will be 1 and click ok.
• Now check sketch , select upper face of spur gear as a plane and project the spur gear diagram on to the plane.
• Add another circle of diameter 110 (must be greater than 96 mm for making ring gear type).
• Now enable 3d sketch and draw a vertical line of 15 mm and finish the sketch.
• Select sweep command and select ring gear diagram and direction will be that vertical line.
• Twist angle will be 15deg and operation will be new component.

4. ### Step 4: Planet Gear

Again open spur gear plug in and follow these steps

• No. of teeth will be 36 with modules 1.
• Also don't forgot to add backlash (any value between 0.1 to 0.5).
• After adding spur gear click on sketch ,select upper face of spur gear as plane.
• Project the spur gear on the plane.
• Draw vertical line of 15mm and finish the sketch.
• Now apply sweep operation, select the drawing and direction will that vertical line.
• Calculation for twist angle is

angle = 15 *(Nr/Np)

angle = 15 * (96/36) = 40deg

• Place this helical gear with the help of move command and also create two copy .

5. ### Step 5: Sun Gear

Add another spur gear with given specs

• No. of teeth will be 24 and module 1.
• No backlash required.
• Now again project the gear sketch.
• Add vertical line of 15 mm.
• Apply sweep operation with twist angle given as

angle = 40*(36/24) = -60 deg

### Important * In the given video i mistakenly add twist angle 60 deg but it will be -60 deg *

Now align the gear teeth with planet gears.

6. ### Step 6: Carrier

I think video will be enough for carrier design.

7. ### Step 7: Assign joint

Use as build joint operation keeping ring gear grounded.

Refer to video for any help .