This is a replacement middle gear for the Aurora AS424C shredder, which tends to break due to excessive motor torque when the paper jams.
This gear is designed with pin holes of 1.1mm (adjustable in the SCAD file) in each of the smaller gear's teeth, so that you can stick metal pins into them for better shear strength without having to print it at an angle.
Update: Now with a hub for the top of the gear instead of pinholes to stabilize the top of the gear.
Print the gear flat, and stick rigid metal pins of 1.1mm diameter, and 15-18mm long into the pin holes for shear strength. Hammer the pins in as far as you can get them. Pins removed from thumbtacks work well for this purpose. Adjust the pin_diameter variable in shredder-gear.scad if you need pins of different sizes.