Dogwood's Watchmaking Journey

[KJ2020]

I had a really interesting project on my bench this week: an AP rep with a clone 3120 movement that had an instant date change mod. I haven't seen this mod before and I don't know if it's been documented here (I didn't look to hard, so maybe I'm wrong). Regardless, the mechanism for the instant date change is quite clever. Here's a pic showing the two date change mechanisms the instant date change is on the left (red arrow), and the standard clone movement mechanism is on the right (blue arrow).



And here are a couple of close up pics of both mechanisms:



And because I know somebody will want a macro view, here's what they look like under the microscope:



The mod consists of three parts (four if you count the screw, which is the same as the stock screw). There's the date gear which has a punched ramp pusher rather than a pin like the stock part, the spring, and the part that looks like the number 6.



The mechanical linkage of how this mod works is ingenious. The 6 part blocks the pin on the spring to build up energy for the jump, and the base of the spring then pushes the end of the spring with the pin on it around the 6 part. To get the date to flip at midnight you need to align the 6 part so that it's slightly "ahead" of the tooth on the date wheel. Here's a video of how it all works.

And here's a video of what it all looks like when the dial and hands are back on:

This is a very cool little mod which I've never seen on an clone AP 3120 before. I think this mod is available from some of the well known modding workshops in China, but I'm not sure if TDs can source it.

I don't know what the gen mechanism looks like. Perhaps @legend can comment.

Very slick mod and great documentation! It's very similar to the date wheel part in 31xx / 32xx movements except that spring has an enclosure around it. This mod is simpler as it interacts directly with the date indicator instead of needing several other companion parts.

 

[dogwood]

I recently posted a full teardown of the new AR+F Daytona movement (the AR4131). Unfortunately during disassembly one of the reversing wheel jewels popped out of the bridge. Fortunately, I have a jeweling tool and love getting the chance to use it. The parts are now in the cleaning machine. Hopefully the jewel stays put.

 

[dogwood]

I finished the service on the AR4131 (Peacock SL-4801) movement which I previously did a tear down on. A few thoughts on the movement now that I've completed the service:

1. The movement isn't bad. There are some nice simplifications that Dandong did over the Rolex design for this chronograph movement. Specifically the pusher lever spring system is a lot simpler than the Rolex design, however, that simplification means that the reset pusher only actuates the reset once. On the gen and DD4130 each push of the reset pusher moves the column wheel and re-engages the reset hammer. This isn't a big deal since usually the chronograph hands reset properly, but I've had one occasion where I needed to hit reset twice to get the hands on one of my DD4130 Daytonas to fully jump back. Obviously it would be possible to simply start, stop, and reset the chronograph on the AR4131 again to refresh the reset. So, not a big deal, and the simplification in design is probably worth it.
2. The combination chronograph and automatic works bridge is quite large and getting it into position without the super delicate jumper for the chronograph minute wheel slipping is a bit harder than on the 4130 where the chronograph bridge is a little smaller and getting it into position isn't as much of a performance.
3. The stem is really hard to get back into the movement. I had to push with a LOT of force to get it the setting lever pin to pop back into the slot on the stem. I mean an uncomfortably large amount of force. The stem on this ARF 126500 was also probably about 0.5mm too short so getting the stem back into the movement inside the case was a struggle. I was worried initially that I'd upset the keyless works, so I uncased the movement, removed the hands, removed the dial, and was going to reset the keyless works, but saw that nothing was out of place. I tried pushing that stem back in without the dial on and saw that I just needed to push really hard to get the stem to push past the pin on the setting lever. I applied HP1300 to the slope on the stem to try to get it to more easily ride past the pin, but I didn't feel a difference. I think it's just tough by design. Also, it doesn't appear to matter which position you remove the stem from, the keyless works look like they would be very hard to upset.
4. There's an adjustable damping spring to reduce stutter and backlash on the chronograph seconds wheel. I didn't see / understand this at first, but after adjusting the position of the damping screw, the stutter can be brought under control (see red arrow in pic below; video shows the stutter when this spring isn't properly adjusted).

Over all this isn't a terrible movement. I don't think AR+F should be charging a premium price for reps with this movement though. I would say the best option for a Daytona remains the DD4130, followed by this movement, and the worst option would be a 7750.

 

[flashu]

Great details l, amazing work as usual !

 

[Theodorius]

Hopefully the jewel stays put.

Sometimes, and based on hole form and location, it helps if you narrow the jewel hole using very gently the staking tool and under strong magnification for best observation. The staking tool needs practice, but after learn it, will be your favorite tool.
I just have a question. Did you notice a proper lubrication on those movements? Thank you for your great contribution.

 

[Antonino]

Hi guys! I can't find a discussion, so I'll ask the more experts here. I have a VS 126610 and would like to change the movement to a VR 32335. I ask you, do I also need to change the dial? Are the VS hands compatible with the VR movement? A thousand thanks

 

[dogwood]

Sometimes, and based on hole form and location, it helps if you narrow the jewel hole using very gently the staking tool and under strong magnification for best observation. The staking tool needs practice, but after learn it, will be your favorite tool.
I just have a question. Did you notice a proper lubrication on those movements? Thank you for your great contribution.

Like most rep movements, this one was a little dirty (lint and dust) and it was a little bit under lubricated. But that’s better than over lubricated.

 

[dogwood]

Hi guys! I can't find a discussion, so I'll ask the more experts here. I have a VS 126610 and would like to change the movement to a VR 32335. I ask you, do I also need to change the dial? Are the VS hands compatible with the VR movement? A thousand thanks

A vr3235 is a drop in replacement for a vs3235. The dial and hands fit.

 

[dogwood]

Sometimes, and based on hole form and location, it helps if you narrow the jewel hole using very gently the staking tool and under strong magnification for best observation. The staking tool needs practice, but after learn it, will be your favorite tool.

Btw: thanks for this tip. I’m still learning the dark arts of staking. I have a Chinese clone of the horotec staking set. I’ve used it a few times, but getting metal to move the way I want it to it tricky. I sometimes describe watchsmithing as being a car mechanic with tweezers and a microscope. If I practice staking I guess it would be like being a blacksmith with a microscope.

 

[Antonino]

A vr3235 is a drop in replacement for a vs3235. The dial and hands fit.

A thousand thanks!! So I don't have to make any changes? does everything fit perfectly? Thank you

 

[dogwood]

A thousand thanks!! So I don't have to make any changes? does everything fit perfectly? Thank you

You’ll need to change stems. Be sure to use heat to break the glue between the threads of the old stem and the old crown. Use loctite to secure the new stem to the old crown.

 

[Antonino]

You’ll need to change stems. Be sure to use heat to break the glue between the threads of the old stem and the old crown. Use loctite to secure the new stem to the old crown.

Thank you!!!

 

[Theodorius]

Also use the heat on the stem and avoid direct heat to the crown. At approximately 300 Celsius the O-rings will be melted and deformed.

 

[dogwood]

New tool arrived today... Over the last few years I've mostly used the standard 40-40 vise style movement holder, but for certain movements (e.g. chronographs) it's really nice to have a bespoke movement holder with pushers in the right place so that it's easy to test the chrono start/stop/reset functions. The problem was always that the official Rolex (or other European) brand movement holders are very expensive ~C$1000. As a hobbyist, that's hard to justify.

A few years ago I noticed that there was a Chinese made 4030 movement holder available on AliExpress. I looked up the dimensions of the 4030 and they were very close to the 4130, so I figured it would be worth a try since the Chinese 4030 holder only cost around C$100. It turned out it worked, but not perfectly. The pushers were in slightly the wrong place. The DD4130 was always a very tight fit in the holder. The holder didn't have cutouts in the right places to access the dial feet clamping screws. In short it wasn't idea.

But a few weeks ago I saw a listing on AliExpress for a Chinese made 4130 movement holder that looked like it had been designed specifically for the 4130. For ~C$50 I figured it was worth giving it a try... it arrived today. It's a big upgrade over my previous 4030 holder. The movement fits perfectly (NB: The pics below are with an ARF4131 which is actually an SL4801 movement which is the "street legal" version of the DD4130). The pushers line up exactly where they need to be, and the holder has cut outs exactly where you need them to access the dial feet clamping screws.

Here's the current link to the AliExpress listing... if you're reading this in the future, don't trust the link (it'll probably be broken), but you should be able to find this holder by searching AliExpress for "4130 movement holder"

https://a.aliexpress.com/_mOYgBmQ

 

[KJ2020]

New tool arrived today... Over the last few years I've mostly used the standard 40-40 vise style movement holder, but for certain movements (e.g. chronographs) it's really nice to have a bespoke movement holder with pushers in the right place so that it's easy to test the chrono start/stop/reset functions. The problem was always that the official Rolex (or other European) brand movement holders are very expensive ~C$1000. As a hobbyist, that's hard to justify.

A few years ago I noticed that there was a Chinese made 4030 movement holder available on AliExpress. I looked up the dimensions of the 4030 and they were very close to the 4130, so I figured it would be worth a try since the Chinese 4030 holder only cost around C$100. It turned out it worked, but not perfectly. The pushers were in slightly the wrong place. The DD4130 was always a very tight fit in the holder. The holder didn't have cutouts in the right places to access the dial feet clamping screws. In short it wasn't idea.

But a few weeks ago I saw a listing on AliExpress for a Chinese made 4130 movement holder that looked like it had been designed specifically for the 4130. For ~C$50 I figured it was worth giving it a try... it arrived today. It's a big upgrade over my previous 4030 holder. The movement fits perfectly (NB: The pics below are with an ARF4131 which is actually an SL4801 movement which is the "street legal" version of the DD4130). The pushers line up exactly where they need to be, and the holder has cut outs exactly where you need them to access the dial feet clamping screws.

Here's the current link to the AliExpress listing... if you're reading this in the future, don't trust the link (it'll probably be broken), but you should be able to find this holder by searching AliExpress for "4130 movement holder"

https://a.aliexpress.com/_mOYgBmQ

Thanks bro, I was just looking to upgrade mine. Just ordered one!

 

[Theatrix]

Appreciate the post.....looking for this!

 

[Theodorius]

Hello and thanks for the great tip!
I am about to order and see that the Silver version is 44,14€, but the yellow version is 75,48€.
Is any particular reason for this, or is just marketing BS?
Thanks

 

[dogwood]

Hello and thanks for the great tip!
I am about to order and see that the Silver version is 44,14€, but the yellow version is 75,48€.
Is any particular reason for this, or is just marketing BS?
Thanks

Yea, the silver version is for the 4030 movement, the yellow version is for the 4130. You want the yellow version. Notice how the yellow version has cutouts along the sides and only has one screw support pin in the center (not two).

 

[dogwood]

It's new tool day... I've always been nervous about removing the ceramic inserts from rotating bezels. The inserts are easy to break and expensive to replace. So a few weeks ago I dusted off Fusion360 and decided to design my own custom bezel insert removal die for the Clean Factory GMT bezel insert. My design requires a 5-axis CNC machine to make due to the angle on the pusher fingers... but I wanted a tool that would push on the insert across as much area as possible so as to avoid any stress concentrations. Here's my design:



I ordered the part on PCBWay which was surprisingly inexpensive for a one off 5-axis cnc'd part (each part was about $40). It arrived and I was happy to see that they actually did make the part on a 5-axis machine as can be seen by the 18 degree angle slope on the pusher fingers:



I was worried that my measurements from the Clean bezel would have been off and that the pusher die would have been off (I designed it with around 0.1mm of clearance between the size of the pusher fingers and the slot holes in the bezel).



The two parts of the die and pusher are very accurate to the specified sizes in CAD (more accurate than I trust my calipers to measure). Here are a couple of videos of the tool and die working with a Clean GMT bezel.

And before anybody asks... I don't plan on selling these. This was just a design project that I thought would be fun. If you're looking for high quality bezel dies, you should check out the full bezel removal die set from @Oascom.

 

[dogwood]

I had a tough movement on my bench this week. It was a dd3285 that was in a watch that had been dropped “3 feet onto a tile floor”. The watch still ram, but initially the time grapher results were all over the place.



Even after a service the movement didn’t run well. I tried swapping out every component between the mainspring and the balance but nothing improved things. I was certain that something had been damaged in the fall but nothing I replaced would help.

I finally decided to take a closer look at the shock settings. I’d serviced these quickly and mostly focused on the cap stones. But when I re-disassembled the mainplate shock setting and looked at the hole from the cap stone side, this is what I saw:




The hole was chipped and oval and there was a crack running across the jewel. I’m shocked (pardon the pun) I didn’t see this the first time.

The movement is running better now. Still not perfect, but better. Seeing this really drove home how delicate mechanical movements are. I’d always wondered why the TimeX slogan “takes a licking and keeps on ticking” was so effective. But if your watch was basically destroyed if it fell off a table, I can see why that slogan helped sell.