# Tutorial: how to model '' a gear '' in '' solidworks '' and show design intent

1. ### Step 1:

01) File, new, part, ok

2. ### Step 2:

02) Tools, equations, add these parameters and equations as shown
m= 6 (module)
z=20 (teeth number)
p= m*pi (pitch)
d=m*z (primitive diameter)
df=d-2*m (foot diameter)

3. ### Step 3:

03) Sketch, select front plan and draw a circle than
replace the dimension by “=” choose “da” (Rq, this is the same procedure for the rest.)

4. ### Step 4:

04) Fuction, extrude, 25 for the thikness

5. ### Step 5:

05) A new sketch in the front face than add 3 circles and in the dimension box write “=” and chose :
The first circle: “df” the 2nd “d” the third “da”.

6. ### Step 6:

06) Add 2 centerlines and mirror the 3rd one
Rq: Be sure that the end of the middle centerline coincide with the “d” circle.

7. ### Step 7:

07) Add an arc in as shown be sure always that the entities hang in the good positions.
The center in the “df” circle and and the ends on “da” and “df”
- Mirror it twice ( reference to the two centerlines)

8. ### Step 8:

08)
- and for the pitch use “=p”.
- and a relation between the arc and the point of the center line.

9. ### Step 9:

09)
When the sketch is fully defined (black), extrude cut and select the two contours.

10. ### Step 10:

10)
Use the circular pattern function and for the number of instance write “=” chose “z”

11. ### Step 11:

And this is the result:

12. ### Step 12:

11)
And now our goal is here to show the result of using the design intent ^^:
(tools, equations) We change the value of “m=9” and “z=28” for example.

13. ### Step 13:

12)
If you enjoy this tutorial be positive and click “it worked” and “like”

Good tutorial. however few steps are vague (steps 6 to 8). like step 6 says to draw to center lines, but no dimensions are given as to what angle are they apart. I am basically stuck at this step. Steps 7 - 8 are not really clear as what is being done what you are referencing in the images. would appreciate a clarification. Also i wonder if these can be used to model several gears in mesh?

thanks.

September 13th, 2018 16:18
• Tarek Zemri

September 10th, 2017 11:05

This is a well illustrated tutorial thanks!

September 10th, 2017 02:05
• Tarek Zemri

Zeke, you're welcome

August 29th, 2017 08:13
• Zeke Levin

Thanks! I needed this to design a planetary gearbox, and this tutorial was super helpful.

August 28th, 2017 17:07