Screw (Crossed Helical) Gear Drive Model

https://youtu.be/3y5DPHl9y2g Our collection of 3D-printable gear mechanisms would be incomplete without the model of a screw gear drive. Screw gears are regular helical gears mounted on non-parallel, non-intersecting shafts. They are also known as crossed helical gears. The shape of this screw gear drive was inspired by the DNA molecule. In this particular model, there are three gears mounted at 45° to each other, but the shaft angle can be any number between 0 and 90°. 3D Printed Parts List:

Qty	Filename	Description
1	sg_base.stl	The base of the model to which the stand is attached.
1	sg_stand.stl	The two-spiral stand to which the gears are attached.
1	sg_bottom_gear.stl	Bottom 36-tooth gear.
1	sg_middle_gear.stl	Middle 30-tooth gear.
1	sg_top_gear.stl	Top 24-tooth gear.
2	sg_lower_axis.stl	The axis on which the bottom and middle gears are mounted.
2	sg_washer.stl	The washer that secures the bottom and middle gear on their axes.
1	sg_upper_axis.stl	The axis on which the top gear, stop tube and spinner are mounted.
1	sg_stoptube.stl	The stop tube mounted on the upper axis next to the top gear.
1	sg_spinner.stl	The finger spinner which sets the model in motion.
1	sg_bridge.stl	The bridge connecting the two spirals of the stand for security.

For assembly instructions, and for other 3D-printable models and modeling tutorials, please visit http://www.otvinta.com.