Step 1: Step 1: Making the Base.

Drag a box onto the workplane.

Resize the box so it has a height of 10mm; a length of 60mm and a width of 60mm.

Step 2: Step 2: Pylons Part 1.

Now drag another box onto the workplane.

Resize this box so it is tall and thin with the height of 60mm ;the length of 20mm and the width of 20mm.

Step 3: Step 3: Pylons Part 2.

Drag a hole in the form of a cylinder to the workplane.

Change the diameter to 10mm and the length to 11mm. We want the catapult arm to move smoothly.

Step 4: Step 4: Pylons Part 3.

Use the teardrop shaped tool that appears just above the object when you click on it.

First use the tool to make the pylon hover 10mm from the workplane.

Second make the cylinder/hole hover 40mm high.

Step 5: Step 5: Pylons Part 4.

Now drag the cylinder/hole so that it is positioned in the cylinder with 5mm on either side.

Step 6: Step 6: Pylons Part 5.

Now group the object.

Group the object by placing the cursor over the workplane and dragging a red dotted line around the hole and the pylon. Then press the button on the top of the screen that shows a square fused to a circle. Now you have grouped your pylon.

Step 7: Step 7: Pylons Part 6.

Copy and paste your pylon and rotate the copy so it's hole is opposite the originals. You now have your two pylons.

Step 8: Step 8: Pylons Part 7.

Manoeuvre the pylons onto the baseplate. Make sure you have no overhangs.

Step 9: Step 9: Pylons Part 8.

Group the pylons and the baseplate.

Group the object by placing the cursor over the workplane and dragging a red dotted line around the pylons and the baseplate. Then press the button on the top of the screen that shows a square fused to a circle. Now you have grouped your base for the launcher.

Step 10: Step 10: Making the Launcher Part 1.

Drag a solid cylinder from the bar and give it the diameter of 9mm and the length of 40mm.

Step 11: Step 11: Making the Launcher Part 2.

Drag another box onto the workpane give it the height of 9mm; the length of 50mm and the width of 18mm.

Step 12: Step 12: Making the Launcher Part 3.

Group the cylinder and the rectangle. make sure the cylinder is in the exact middle of the rectangle.

Group the object by placing the cursor over the workplane and dragging a red dotted line around the cylinder and the rectangle. Then press the button on the top of the screen that shows a square fused to a circle. Now you have grouped the catapult for the launcher.