The Miyota caliber 9029 is a member of 90/91 family of watch movements. This caliber is part of Miyota’s “Premium Automatic” line. It tells the time via a 2 hand display with no seconds hand and no date option. The unique design element of this movement is that it has an open-heart (aka open balance wheel) on the dial around the 5:00 position. This movement has 24 jewels and is made in Japan.
Some of the topics covered in this caliber listing:
9029 VS 90S5:
There is a similar and more common Miyota caliber 90S5. Both are 26mm in diameter, have 24 jewels, both beat at 28,800 vph, and have the same dial feet location. The main difference is that the 90S5 is a 3 hand watch with a sweeping second hand. Also, the 90S5 has a decorated gilt front plate that may add to the aesthetics of the open balance feature depending on the dial design.
The caliber 9029 is a no-date movement so the crown only has two positions: winding (position 1) and time adjusting (position 2). The set the time on your 9029 powered watch, pull the crown out one click to position 2. You may need to unscrew the crown if it is a divers style watch with a screw-down system.
Winding + Power Reserve:
Winding this movement 15-20 clockwise will start the movement. To fully wind the movement, turn the crown 40 times. The power reserve when the movement is fully wound is supposed to be more than 42 hours.
Miyota claims that the caliber 9029 offers accuracy of -10 ~ +30 seconds per day. This is measured within 10-60 minutes from a full wind via the crown.
At the time of this post, caliber 9029 replacement prices were found online in the range of $99.00 – $115.00 USD.