Herringbone gear

A chevron gear whose opposed helices cancel axial thrust.

A herringbone gear is two opposite-hand helical halves meeting in a chevron. The opposing helix angles cancel the axial thrust a plain helical gear produces, so no thrust bearing is needed — which makes it a favourite for 3D-printed drives. The two halves are unioned into one editable part, aligned so the teeth run continuously across the join. To build a whole meshing line of them, use the herringbone train.

1. Open the Generate panel from the left sidebar and choose Herringbone gear (under Gears & drives).
2. The gear drops in as one editable part. The parameters open in the Properties panel, where you set them.
3. Set the module, tooth count, and pressure angle.
4. Set the helix (chevron) angle, total thickness, and bore.