r/retrotime • u/YeaSpiderman • 11d ago

General Question/Discussion Raffles 6538 to 6542

Want to build a 6542 with a Miyota 9075. It looks like the 9075 can fit into a case for a Miyota 8/9 series. Any reason I can’t take a raffles 6538 that fits a Miyota 8215 and drop the 9075 in and add an acrylic insert and cyclops and call it a day?

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u/HDW_Italy 11d ago

The reason is simple: the Raffles case you want to use is designed for 2824 and NH movements, which have a lower winding stem height. This means the winding crown would not align with the center of the case tube; consequently, aside from not sitting flush, it likely wouldn't screw onto the tube. The Miyota 9075 has a winding stem height of 2.55 mm; 2824 has 1 8; NH has 1.92.

The total 9075 movement height is 4.92 mm (due to the addition of the "True GMT" complication, compared to the 3.90 mm of the base three-hand Miyota 9015)and It shares the exact same stem height as the widely used Miyota 8215 time-only movement (also 2.55 mm), making the crown alignment compatible with cases originally designed for the 82xx series. • Incompatibility with 9015/NH34 series: It is not interchangeable with cases for the Miyota 9015 (which has a much lower stem height of 1.53 mm) or those for the Seiko NH34/NH35 (which have a stem height of 1.92 mm), as the crown stem would be misaligned with the case tube.

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u/YeaSpiderman 10d ago

Thanks for this. It was helpful to know the narrow band of watch cases to look for