Thursday, December 24, 2009

MD-703 bezel..

While I was taking the photographs for the review of the Casio MD-703, I notice that the bezel would not rotate smoothly. I decided to see if I could do something about it. So I removed the bezel retainer on the MD-703. Then I remove the bezel by prying it out. Well I found out why it would not rotate smoothly. It was full of gunk. I shall not post pictures of how bad it was. I had all the parts cleaned and these are photographs after the parts have been cleaned. It is also the assembly of the bezel.

This is the ratchet mechanism. It is just a thin steel plate with 3 cut-outs that has been bent upwards. Simple but works. I guess 1 would be enough but I guess having 3, gives it more strength. The simple design also prevents the bezel from turning the wrong way and thus the uni-direction rotation of the bezel.

Another view.

The plate is held in place by the 2 locating pins. The design is very good in that the pins are Murphy proof. There is no way to install the plate in the wrong location.

This is the bezel. It has been cleaned. If you notice, the bezel has a groove. This groove sits in the bezel retainer. This prevents the bezel from accidentally popping off. If you see, the bezel is well made.

A closer view of the cut-out.

The underside of the bezel. Note the notches. There are 60 (I did not count) of these notches. These are the notches that will align with the metal foot of the ratchet mechanism. The feet will fall into these notches and keep it in position and at the same time prevent it from rotating the wrong way.

Don't forget to lubricate the gasket/ o-ring inside the bezel. The all ensure that the bezel rotates smoothly. Actually, the gasket also provides some friction or feel to the bezel movement. I could not find a replacement gasket so there are some horizontal movement of the bezel (some play). This is due to the gasket wearing out over the years. This watch is 20+ years old.

The bezel retainer. It is held to the main body or case by 8 screws, 2 at each mounting point.

The underside of the bezel retainer.

The main watch case. Here you can see the alignment hole for the ratchet plate and also the mounting hole for the bezel retainer.

A closer view. If you look closely, you can see the groove where the o-ring sits.

The other side. You can see the other alignment hole for the ratchet plate. You can also see the thickness of the crystal.

The ratchet plate is installed.

The other side.

The bezel is installed. You will need a press to push the bezel as it is very tight. Since I do not have a press, it was putting the watch upside down on a wooden stool and pushing it down with my weight. Don't forget to use a cloth to prevent damage to the bezel insert or use one of the flat pack stool made by that Scandinavian furniture company. Use the pine wood version as it is rather soft.

The final product. Now it rotates smoothly and clicks in place with resounding gusto. Now, where is that other MD-703.....

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