Asset Overview
The second of 3 mechanisms doing the same thing, but using different solutions. All of them have a 1:1 relation between input/output, but while input is continuous, output changes with time.
This one uses a planetary (sun/arm/planet), combined with a cam/follower mechanism. The planet gear is partial and it has a follower pin, which slides inside a circular groove cam, placed dislocated to the sun axle. The speeds add/subtract, resulting in an intermittent movement.
The input here is the planetary arm (green) and the output is the sun (blue) and the needle (yellow). The groove cam (white) is fixed and the planet (red) contains the cam follower pin.
Modeled with Solidworks 2015.
Rendered with Simlab Composer 6 Mechanical Edition.
Video at https://youtu.be/tMn4cMWr4aI.