NH35 movement swap into a JK Factory sub - Tutorial

[NCRich]

Anyone know if a nh35 would fit a Silix rol234 the 6538 big crown one?

It will, you may have to either shim or trim the plastic spacer. I did one, but I can't remember which I had to do. That case is for a 2813/2836 or equivalent.

 

[trust_wrx]

Hey Rich,

Amazing work! Thanks for sharing your work with us!

Im planning to do the same with my Pagani Sub (James Cameron colour dial lol), but currently considering options for dial swapping.
I plan to keep the NH35, case and bezel assembly, just pick a raffles dial (decide on keep date or do a DWO and AR cyclops), then swap the clasp and crown for raffles Rolex items. Really want to do a 29mm Khanjar Dial Sub.

The thing thats holding me back is being unsure about what size dials these watches can take. Am i only limited to 28.5mm, or can i go up to 29mm?
since your rehaut opening is measured at 26.9, i can go for pretty much anything between 27 and 28.5mm?

Am I understanding this correctly?

 

[NCRich]

Hey Rich,

Amazing work! Thanks for sharing your work with us!

Im planning to do the same with my Pagani Sub (James Cameron colour dial lol), but currently considering options for dial swapping.
I plan to keep the NH35, case and bezel assembly, just pick a raffles dial (decide on keep date or do a DWO and AR cyclops), then swap the clasp and crown for raffles Rolex items. Really want to do a 29mm Khanjar Dial Sub.

The thing thats holding me back is being unsure about what size dials these watches can take. Am i only limited to 28.5mm, or can i go up to 29mm?
since your rehaut opening is measured at 26.9, i can go for pretty much anything between 27 and 28.5mm?

Am I understanding this correctly?

It is going to depend on the case but I would bet that it would hold a 29mm. You can alway measure it if you have a caliper. I ALWAYS measure. Learned that the hard way.

 

[KJ2020]

Hey Rich,

Amazing work! Thanks for sharing your work with us!

Im planning to do the same with my Pagani Sub (James Cameron colour dial lol), but currently considering options for dial swapping.
I plan to keep the NH35, case and bezel assembly, just pick a raffles dial (decide on keep date or do a DWO and AR cyclops), then swap the clasp and crown for raffles Rolex items. Really want to do a 29mm Khanjar Dial Sub.

The thing thats holding me back is being unsure about what size dials these watches can take. Am i only limited to 28.5mm, or can i go up to 29mm?
since your rehaut opening is measured at 26.9, i can go for pretty much anything between 27 and 28.5mm?

Am I understanding this correctly?

If you have some extra space outside the minute tics on a 29mm dial as most do, it's very easy to shave a little off the dial. Especially this tiny amount (0.25mm all the way around) would take very little time and effort.

You can shave a dial by hand. See Post #19 if interested

Dial shaving made easy - DIY

ARF dials often seem to be a tad larger than other factories. ARF Daytona dials are well known to need shaving to fit in a Noob case. I had to shave this ARF GMT dial down to fit it in a VRF case. I found a unique way to safely DIY shave a finished dial that may be useful for others. The...

forum.replica-watch.info

 

[trust_wrx]

Many thanks @NCRich and @KJ2020... really appreciate your feedback..

i think you are absolutely right, best thing to do is take it apart, measure it then i will KNOW for sure. then i will know what to do.
I believe i should do this first even before i order anything.

Ill update here about the Pagani Case dial acceptance when i get around to doing it.

Cheers,
Shannon

 

[bcapa40]

One of the negative things about the NH series I don't like. It cannot be mounted with steel case screws and clamps like a DG2813.

 

[est4129]

I was looking at pics of the nh3x movements and noticed a couple holes on the movement holder. Is there a reason you could not get a very small self tapping screw and use it to hold a case clamp on these?

 

[Jip7645]

Wish I’d seen this thread sooner, I was swapping an nh38 into a cartel 6538 last night, had a little bit of wiggle room in there so I cut a small piece from a dial spacer ring I had lying around, stuck that to the movement holder and it fit perfectly, your way is more efficient though

 

[qjai89]

Did anyone run into issues with the dwo adding too much pressure on the plastic calendar fast wheels?



I have broken 2 nh35 movements so far assembling a raffles dj. The datewheel turns but the added pressure snapped off a tooth from the plastic wheel mechanisms both times. Using dial dots to attach the dial to dial feet I thought there would be enough clearance but once fully assembled I think the dial is slightly putting pressure on the datewheel. And since the nh35 doesn't have an accompanying dial spacer, i feel like I'm out of luck and don't want to kill another nh35 movement haha. Thanks in advance!

 

[Karbon74]

Did anyone run into issues with the dwo adding too much pressure on the plastic calendar fast wheels?



I have broken 2 nh35 movements so far assembling a raffles dj. The datewheel turns but the added pressure snapped off a tooth from the plastic wheel mechanisms both times. Using dial dots to attach the dial to dial feet I thought there would be enough clearance but once fully assembled I think the dial is slightly putting pressure on the datewheel. And since the nh35 doesn't have an accompanying dial spacer, i feel like I'm out of luck and don't want to kill another nh35 movement haha. Thanks in advance!

Maybe add this

What is a watch dial washer? - The Watch Doctor

The function of a dial washer is to prevent the hour wheel from rising and disengaging from the pinion on the minute wheel that drives the hour wheel. The dial washer is also critical for keeping the hour wheel in place when the watch is turned over into the dial down position. Sometimes the...

blog.watchdoctor.biz

 

[WatchN3RD]

Dial washer is a great suggestion if you aren't using one. Also, maybe you could try to use an nh34 movement spacer/holder instead if you're using the nh35 one. It fits identically, but there's likely more clearance since the NH34 has 4 hands vs. 3.

Separately, has anyone successfully used a seiko NH movement using mounting tabs instead of the supplied plastic spacer and holder? Has it been done by anyone that didn't make a custom spacer on a lathe?

 

[grasscla]

So I've always been dissatisfied with the DG2813 and even less satisfied with a more expensive asian clone of a 2836 in a vintage Rolex sub. They are both assembled by small Chinese children in a dirty factory and they have no lubrication in the movement. To add insult to injury the 2836 clone is the wrong beat rate, and is more expensive. Still crap. If you get a low beat Swiss pulled out of some old watch then it needs service to be decent. Swiss 2836 still have the wrong beat rate.


So enter the Seiko NH35. Its a tank of a movement, still built by asians but in a clean factory with oil and QC. Its got the right movement and is one of the most popular automatic movements in the world. Purported to run for years through abuse and neglect. Its got pretty much the right beat rate. Only real beef anyone has with it is that its not quite as accurate as the vastly more expensive Swiss ETA 2836. But it can be had for $35-40.

I searched the boards and found people talking about how it was a waste of time trying to swap these in. Wrong hand size, need gasket fabricated, datewheel, etc. I looked at the specs and found not much difference at all. Hand sizes:

NH35 150/90/21

DG2813 150/100/17

ETA 150/90/25

The case sizes, stem height, and movement height are very close as well. When you figure in the plastic gasket the NH35 comes with its damn near a perfect fit. So lets see how to do it. I'm going to use my trusty old test DRSD. Its had damn near everything smacked about on it. Even got a countersunk Athaya crown.





So here is the NH35 with the plastic gasket it comes with.

Here is the donor 2813 that came with the watch. I use a single edge razor blade to carefully pry off the date wheel overlay.

Here are both movements, I've moved the overlay onto the NH35.

I glued the DWO onto the NH35 date wheel with a 5 minute epoxy. I like to line up the 3 with the stem.

Lay the dial on to see how it fits. Got some time to move it.

Hands are going to be the wrong size. I'm just going to go to my BIG BOX O HANDS and pick the closest.

I ended up using the 22 for the sec hand, and had to broach minute hand to fit. Just a bit. Both the handsets and the movements probably have .5mm error margins so it was no big deal.

I put the dial on using double stick tape.

The tape actually serves a double purpose, it holds on the dial but also adheres to the back of the rehaut to keep the movement in place.

Hands on!

Movement seated, looks good but just a little loose in the case.

I'd measured all this stuff long before I started and ordered an appropriate gasket to snug it up. I put it in before the stem was inserted.

All in! Fits like a glove.

And, the finished product!

Thanks for watching!

UPDATE

OK, there are the differences in dealing with the 5512 thru 1680 cases rather than the sea dweller case. The plastic spacer on the NH35/36 is a bit too large for this case. The solution for this is to snap the plastic case off the movement and use a dremel with a drum sanding bit to take the outer edge of the spacer down to size. Take your time and for God's sake don't do this with the spacer still on the movement as you will get plastic dust inside the movement. You need to take maybe 1/16 or so off to get it to fit. Then snap it back on the movement. After that all the other directions are the same.

Nice! Waiting on the movement rn, do you think I would need an additional dial washer to complete everything? I’m afraid of breaking it if the date doesn’t have enough clearence

 

[NCRich]

Nice! Waiting on the movement rn, do you think I would need an additional dial washer to complete everything? I’m afraid of breaking it if the date doesn’t have enough clearence

No the movement gasket that comes with an NH3X serves as the spacer.