Herringbone Rack and Pinion Gear Set

thingiverse

Here is a herringbone (or double helical depending on your source) gear rack and pinion. The design was made to connect to 12v gear motors to provide linear motion but could be used anywhere you need. The specific intent was to have a 4 inch path of travel per rotation of the motor/gearbox output shaft, so this rack and pinion was not made to fit anything existing and should be considered custom. Gear design properties: - 20 deg pressure angle - 45 deg helix angle - 0.75 inch width gear tread Pinion properties: - 1 inch overall width (0.125 inch on either side of gear tread) - 0.3125 center bore - Actobotics hole layout (6-32 bolt and 0.770" spacing) for mounting to clamping hub; if another hole layout is needed, comment and I can create/upload - 4 inch circumference to ensure 1 rotation travels 4 inches linearly Rack properties - Length varies; designed such that any size can fit together, one after another - 0.181 inch diameter mounting holes with 0.335 inch diameter head clearance Rack Lengths: - 12 inch - 9.777 inch - 8 inch - 5.777 inch - 4 inch - 2.222 inch Comments on ways to improve this design are welcome. If any other length rack or pinion hole layout is needed, let me know and I will upload. This is a work in progress.