Exercise #5 Two-Stage Gearbox

Exercise 5: Two-Stage Gearbox

In this exercise, you'll be CADing and assembling a two-stage gearbox. The goal is to build experience with more advanced gearbox designs. Additionally, you'll learn how to use the Part Lighten Featurescript to optimize and reduce weight in your components.

Navigate to the "Exercise #5 Two-Stage Gearbox" tab in the copied document and follow the instructions to complete the part studio.

Create a Layout Sketch

Draw pitch diameter circles for the 60-tooth and 20-tooth gears. Make them tangent to define the center-to-center distance between the gears. Then, constrain the gear centers so they align vertically and horizontally.

Create a new sketch for the motor plate.

Using the layout as the reference, draw 14mm holes for the bearings. Note that depending on your manufacturing processes and tolerances, you may need to draw your bearing holes slightly larger or smaller.

Add four mounting holes for connecting the motor plates, and begin adding circles to create the geometry of the plate.

Finishing Top Plate

Using center lines, sketch fillets, 3-point arcs, and the mirror tool, finish sketching the geometry of the top plate.

Extrude the motor plate to be 4mm thick.

Creating Spacers

Create spacers by making the inner diameter 4mm and making the outer diameter the same as the sketch fillet.

Then, extrude the spacer by 12 mm.

Creating Bottom Plate

By using the "Use" tool (the cube), you can copy the geometry and holes of the top motor plate. Then add a 16x16mm center point rectangle for the motor mount and mirror it to the other side.

Then, extrude by 4mm.

Countersinking Screw Mounts

Now create holes for the screws by making circle with a diameter 8mm, extruding them by 2mm, and fillet them by 0.5mm.

Creating the gears

Make the gear have 60 teeth, make it 5mm deep, and make its module 0.8. You can also hide the top plate for a better view of the gear.

Make a second gear with 20 teeth, and 5mm deep, and make its module 0.8 as well.

Pocketing the Top Plate

In order to pocket the plates, make sure to make a new sketch and create rib lines. Now use the "Part Lighten" Feature Scripts and click on the top plate and the new sketch you created for the rib lines.