≈ approximate: rests on a figure that isn't a standard's or a
maker's. Hover any value for its source.
Threaded screw holes
How tight a hole a set screw cuts its own thread into — it depends on your printer and
filament, not on the gear. It applies to every set screw held by its own thread, in the pinion's
hub and the gear's, and is saved with each design; new designs start from your default.
Captured-nut screws pass through a plain clearance hole and heat-set inserts use the hole you
enter, so these settings don't change them.
0% = the screw's outer diameter (no grip) · 100% = its root diameter (full thread)
The screw grips on the flats; the corners give the plastic somewhere to go.
Hub pin strength
The most torque the hub pins carry from the part to another pinned against
one of its faces — a flange, a pulley, a shaft collar. Three things can give: the pins shear
where the two meet, or they crush the holes in this part or in the mating part. The lowest of the
three, over the safety factor, is the maximum operating torque.
Material values are typical (estimates), for printed walls; bearing is
taken as the printed walls' tensile strength. Printed plastic creeps under a steady load, so keep
the safety factor up for a constant torque. The teeth and the shaft drive are not rated here.
📁 Import Design
Every STL, STEP, SVG or DXF downloaded from this tool, pinion, gear or pair, carries the whole design and the page
as it was. Selecting one here puts the page back. Import is a step like any other: Undo takes
it back.