Jump to content

First Watch Project


Recommended Posts

Hi everyone

This is my first real post on this forum and my first ever watch project.

I have this Boccia watch dating from about 2000, the movement was starting to fail and the crystal cracked so it has been unused for several years.  It had a nice lightweight and slim titanium case, sapphire crystal and a Myota 6m12 movement - now discontinued.

1618400172_IMG_25501.thumb.JPG.571a034891a1d31e03ca3b2fd85928fa.JPG

My plan is to replace the crystal, fit a new quartz movement (probably a Ronda 703) , replace the face (which I dont like at all) and re-lume or replace the hands.

One thing I am not sure about is which hand fitting height to order.  To align the stem with the casing hole the watch dial needs to be nominally 0.9mm thick 

Looking at the Ronda drawing    https://www.ronda.ch/fileadmin/user_upload/Products/TA_BA/detail/3316001.pdf    confuses me a little and I would appreciate if anyone could confirm if I have got the following right:

1  The dial seat -  Common sense says this is where the movement touches the back of the dial, is this correct?

Assuming it is correct

2  With a 0.9mm dial and hand fitting height No 3  I would have 0.38mm between the hour hand and the face and the second hand would be 1.09mm above the face?

3  With a 0.9mm dial and hand fitting height No 4  I would have 0.73mm between the hour hand and the face and the second hand would be 1.44mm above the face?

4  I will have a minimum of 1.65mm between the face and the crystal (the seal will add a bit) so I assume either of the above will fit OK? 

5  Would No 4 be the best hand fitting height to go for bearing in mind the 0.9mm dial thickness may not be exact?

Any advice much appreciated.

The case has polished up real nice - but that is the easy bit :biggrin:

494346731_IMG_25551.thumb.JPG.f96b2b13c6d08b79bdcd7a3cb42dfcfd.JPG

Thanks

Mike

 

Link to comment
Share on other sites

cool. good luck with it. I am not overly familiar with the ronda 703. I have played around a bit with the 515. If it will fit, it is my understanding that it's dial feet position are the same as the ETA 28XX calibers. this would give you a lot of dial options.

  • Like 1
Link to comment
Share on other sites

1 hour ago, mysterymike said:

I am not planning on using any dial feet but will machine a movement holder/spacer out of delrin which should hold the movement securely and concentric to the dial.

Not a good idea in my opinion, you may think that dial feet are old thinking, but they are perfect for what they hey do. Friction is not a good thing in a watch, parts should just fit precisely. 

Link to comment
Share on other sites

The idea was to make a movement holder and dial that are both a light press fit inside the case, if necessary they can be glued together.  The back of the holder will be machined  so the movement fits in snugly.  There will be a small gap between the movement and the back of the case that will need a plastic or foam shim to keep everything tight.  I would be relying on the stem and the shim to stop the movement rotating.   For belt and braces I could also add dial dots but only if absolutely necessary.

I cannot see why this wouldn't work - but you could fill a library with what I don't know about watch making :)

Making the dial will be the hardest part of the project so I want to avoid the complication of adding dial feet if I can.

I have not found any suitable ready made dials that I like and even if I do, I suspect the feet are unlikely to be in the right place.

  • Like 1
Link to comment
Share on other sites

Probably stating the obvious, but a couple of errors I've made with my own current project.

I'm using a convex dial and a Miyota 2033 which obviously will not sit flat against the underside of the dial, so I used dial dots. As luck would have it, the dial dots bring the module into line with the stem. The problem I have is I need to shim the unknown gap between the dial and the hour wheel to stop it disengaging when it is turned over.

I might try a bit of rodico in the gap and try and measure it. I don't like the idea of placing a spacer under the case back in case something gets squashed and distorted. I would have thought a close fitting mov't ring and the stem would hold things in place.

Link to comment
Share on other sites

Hi eezy, not sure what you mean by the gap between dial and hour wheel?

The rodico idea - measuring to see what the gap is is a  great idea.

I was going to machine down the movement holder until tightening the back up keeps the dial in place and then make a spacer to go behind the movement and finish flush with the holder.  

Link to comment
Share on other sites

5 hours ago, mysterymike said:

Hi eezy, not sure what you mean by the gap between dial and hour wheel?

The rodico idea - measuring to see what the gap is is a  great idea.

I was going to machine down the movement holder until tightening the back up keeps the dial in place and then make a spacer to go behind the movement and finish flush with the holder.  

On top of the module in the centre is the wheel and pinion which the hour hand attaches to. Usually nothing holds that in place but a dial washer. In my case using a convex dial, I have a gap there which allows the wheel to come out of mesh when it is tipped up. My gap is bigger than the washer so I need to make a deeper one to make it up.

Link to comment
Share on other sites

You could also keep an eye open on Ebay as the original 6m12-3 movements still pop up New now and again, I picked one up as a spare last week. Which would save the problem with the mounting ring unless you want to mod it anyway.

Link to comment
Share on other sites

I am not planning on using any dial feet but will machine a movement holder/spacer out of delrin which should hold the movement securely and concentric to the dial.

For project watches with missing spacers, I sometimes 3D print spacers if the nett shape is too complex or time consuming to machine. I can cad model and print in a fraction of the time it takes to machine from solid. The results are as good as the original part, although not authentic of course - but ..... the watch is returned to a running and wearable status.


Sent from my iPhone using Tapatalk
  • Thanks 1
Link to comment
Share on other sites

  • 3 weeks later...

I received my Ronda 703 movement today, it had a couple of extra parts with it that I have no clue what they are for.

The first is a brass coloured washer  - roughly 2mm outside diameter, 1mm inside diameter and curved.

The second is brass coloured plate about 5mm x 1.5mm with an open ended hole at each end.

Does anyone have an idea what these are for?  

Link to comment
Share on other sites

Just googled dial washer and the first part is definitely a dial washer - not sure if I need it though.

I will struggle to photo the other part it is so small - I am of out now will have a go later today.  It is only about .5mm thick.  I was wondering if it is some sort of strap to secure the movement in place.

Link to comment
Share on other sites

I have studied the data sheet at some length and there is nothing obvious to me.

On the right of the frame drawing there are a couple of sections showing 2 screws - I assume ?  these are for fixing the movement and the strap might just fit these screws - but I would then expect two straps to be supplied to fit the two screws.

Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Hold the crown when in winding position, move the click away from the crown wheel, and then while holding the crown let it slowly unwind. I recollect that you must remove the automatic device bridge first, but maybe I'm wrong. You can first try without removing the automatic device bridge.
    • nevenbekriev- You nailed it with your description of me and my reaction when the clock started ticking again. I am a newbie.  I love the sound and idea of mechanical clocks but the idea of owning one and trying to keep them running has never appealed to me. My wife bought this one and an antique German wall clock.  When I looked into having someone repair them for me, the universal response was "it's really expensive to work on them, you should just replace the movement". So, I had nothing to lose, I started researching them and opened them up. The wife is happy because she hears the sound of the clocks again. But I have gone down the "accuracy" rabbit hole. In the vertical position, the balance wheel was not floating. It was sitting on the bottom of the frame. I adjusted the lower spring collet and got it floating. It easily passed the 270 degree 3 to 5 minute oscillation test. It took 8 minutes for the wheel to completely stop moving.  I put it the unit back in the movement and checked the safety pin. It does not touch the safety roller anywhere in +/-270 degrees rotation from neutral position. But the amplitude of the rotation with the spring fully wound is weak based on what you are saying. It rotates +/-90 degrees from the neutral position.  No, I did not take the movement completely apart.  That seemed way outside my skill set at the time. There is a reason I became an electrical engineer and not a mechanical engineer. I am much more comfortable with moving electrons than tiny moving metal parts. Will I do it in the long run? Anything can happen. I don't seem to be able to let it go.
    • Isn't that the same guy who told Zelenskyy to escalate the war with Russia/Putin when they already had a peace deal? 2 years later and we have half a million young Ukranian boys dead. He doesn't seem very clever...
    • Thanks guys.  quick question. For automatic movement, particularly this one. can I power down the main spring by pushing this rachet down?  i've gotten pretty used to SW210 and powering down a manual movement. But so far i've only been waiting for the auto movement to run out of juice before opening the case.     
×
×
  • Create New...