Exploring A Cyma R-424

[Medtner]

Hi, and thanks again for the nice welcomes in my post in the "Watch on your wrist"-forum.

 

As mentioned I bought a Cyma Watersport watch (ladies watch - it being so small? I don't know how this works - not that it matters). It was for sale in a second hand store for about £5, and I thought that it would be a fun experiment even if it doesn't work.

It has an R-424 movement and is the first complete watch I have bought for my hobby (I have a number of practice movements).

 

It is incredibly small, and the first thing I noticed was that my screwdrivers weren't even close to being small enough to get to the dial screws. So work stopped untill I got a new delivery of tools. 

The case back opened after much, much hard work with the case back opener. I probably should get a watch holder so that I don't have to hold it in my hand. 

 

The movement looks reasonably good, but it seems dry and there is a bit of dust/dirt in there. Don't know how it got in there, though - it seemed very tight.

 

Here is the dial and the dial side of the movement, having used my smallest screwdriver of 0.6mm to open the dial screws. Having learned many of the good habits from Mark Lovick's videos I screwed them back in. They were so small that I would have lost them. The dial and movement is sitting next to tweezer 5, for size comparison. Good thing I have a reasonably good eyesight.

 

On the other side, not quite in focus.

 

 

I'm going to strip it all down and do some cleaning and then put it back together and oil it. This being my first attempt at a service I'm having a couple of questions.

 

- When I bought the watch it was basically fully wound (the mainspring seems very healthy, it unwinds when I let it down and it behaves nicely, so I'm thinking it is not broken), but didn't run. It can run for a few seconds when horizontal - the balance probably don't like being "out of balance". Could this be simply that the oil in the pivots/endstones is dry and crusted? 

 

- I don't have a cleaning machine, nor do I have bought any cleaning solutions. Any recommendations for how to go about cleaning it? It doesn't have to be a first rate cleaning this time around. Or does it?

 

I am sure I have more questions, but these are the the most important ones now. 

This is so much fun! I hope I will find more interesting watches in other flea markets and second hand stores. This Cyma was probably headed for the trash if someone didn't rescue it, and it is probably a couple of easy fixes to get it running nicely. Besides - it is an interesting movement, with the weird Cymaflex shock absorbers. :-)

 

Best,

 

Erik

[clockboy]

I have not worked on a CYMA so someone else might have a better input. On the dial side the jewel @ approx 6 o,clock looks strange the way to is being held in place. I could be wrong but it does not look correct.

Edited January 15, 2015 by clockboy

[Medtner]

Yeah, I was looking at those jewel holders, but this seems to be consistent throughout the movement. Cyma seem to have found other solutions than normal. Look at the balance too - weird concept, but seems easy to deal with. :-)

[WillFly]

That balance is very similar to my Cyma 454 - and they do look weird. The only difference is that the lever enclosing the jewel on my balance has two horns on it - yours has one, though it doesn't look as though one has broken of. Here's a pic for comparison:

 

[Medtner]

Interesting. I must give the lever a closer look.

Nice of them to put extra lines on the crown wheel screw on yours - I haven't unscrewed mine yet, but I bet it screws out the other way than usual (left threaded, isn't that what it's called?).

[WillFly]

Yes - the scored crown wheel indicates a left-hand thread.

[bobm12]

I think there is something missing (jewel?) on the top, center wheel pivot...(bottom is the dial side). Just it is not clear to me from the picture. This might be the problem. Check also for broken pivots on any of the other wheels. Hope it helps,

 

Cheers,

 

Bob

[anilv]

Probably a 15 jewel movement with a bush instead of a jewel.

This is not a centre seconds so no need for a jewel here.

Anil

[Medtner]

For a beginner like me, the Cyma is a treasure hunt. It's a fairly classic setup, but some clever solutions that I've never seen before.

 

One of the first things I saw was that the setting lever spring is covered by a small screwed-down plate. Very kind of the designers to have that security to keep the spring from leaping across the planet. :-)

 

Otherwise a very standard setup.

 

 

I'm happy to report that there were no broken pivots. I can't find any place where there seem to be missing jewels...

 

Some of the wheels were sticking to the plates and bridges (and each other) when I took the movement apart. Maybe this is a sign of over-oiling in the past? And perhaps this is at least part of why it is not happily running. I'll see if I can clean it somewhat and put it back together and see. :-)