Cal. 3021LU is a hand-winding movement with moon phase from Naoya Hida & Co. based on the ETA 7750 ebauche. Hida’s latest movement, Cal. 3021LU uses the Cal. 7750 main plate, barrel, wheel train, and escapement with a custom 3/4 plate and balance cock. The automatic winding system is removed, replaced by a custom click for hand winding, and the chronograph and date complications are removed. It lacks a seconds hand but uses the moon phase complication from ETA’s 7751 at 6:00. This adds 1.3 mm compared to the small seconds Cal. 3019SS and 0.6 mm compared to the central seconds Cal. 3020CS.
Cal. 3021LU was introduced with the Naoya Hida Type 3A in 2021. It has been used in the following Naoya Hida watches:
- 2021 NH Type 3A (15 sold)
- 2022 NH Type 3B (15 sold)
The NH Cal. 30 Family
All three Hida movements to date have a similar appearance, and all are based on the 7750 ebauche, wheel train, barrel, balance, and escapement. The small seconds and moon phase movements likely share the same balance bridge and plate, and both feature 18 jewels.
The central seconds hand on Cal. 3020CS is driven using a rear-mounted wheel, requiring a secondary plate at the center. It also features four extra jewels, for a total of 22.
Cal. 3021LU, used in the Type 3, uses the moon phase mechanism from ETA’s Cal. 7751 but omits a seconds display entirely. Like Cal. 7751, the moon phase indicator is adjusted with the crown in position 2.