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NCRich

Seiko NH35 swap in a JK Factory DRSD or Sub - Updated Tutorial to include the 1680 case

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NCRich

EDIT:  Since I created this tutorial I have discovered that the interior dimensions of the sub is different than the DRSD.  It is smaller, and thus requires a slightly different approach.  All the JK subs use a case marked for the 1680 Rolex.  Only the dials are different.  So I've placed a note at the end about how to deal with that.

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.

IMG-6415.jpg


IMG-6417.jpg

 

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.
IMG-6418.jpg

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


IMG-6419.jpg

I glued the DWO onto the NH35 date wheel with a 5 minute epoxy.  I like to line up the 3 with the stem.
IMG-6421.jpg

Lay the dial on to see how it fits.  Got some time to move it.
IMG-6423.jpg

Hands are going to be the wrong size.  I'm just going to go to my BIG BOX O HANDS and pick the closest. (Note: you can just buy mercedes hands for the Seiko from several suppliers)


IMG-6425.jpg

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.


IMG-6427.jpg

I put the dial on using double stick tape.


IMG-6430.jpg


IMG-6431.jpg

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.


IMG-6432.jpg

Hands on!


IMG-6433.jpg

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


IMG-6435.jpg

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.


IMG-6436.jpg


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All in!  Fits like a glove.


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And, the finished product!


IMG-6445.jpg

Thanks for watching!

OK, here are the differences in dealing with the 1680 cases.  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.

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semperfi55
7 minutes ago, NCRich said:

had to broach minute hand to fit.  Just a bit.

Please please do a tutorial on broaching!

 

Also, from the photos above, did the DG2813 originally come with a DWO that is attached to a date wheel mechanism with radial spokes from the centre? And then you pried off the DWO from that mechanism to glue onto the Seiko movement?

Do you use hypocement glue or those epoxy A+B type for gluing the DWO?

 

So many questions. Thanks for the proof of concept :D 

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Nikosaldente

Great tutorial Rich and nice swap!

Looking forward to seeing your answers to semperfi55's questions!

Cheers!

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NCRich
39 minutes ago, semperfi55 said:

Please please do a tutorial on broaching!

 

Also, from the photos above, did the DG2813 originally come with a DWO that is attached to a date wheel mechanism with radial spokes from the centre? And then you pried off the DWO from that mechanism to glue onto the Seiko movement?

Do you use hypocement glue or those epoxy A+B type for gluing the DWO?

 

So many questions. Thanks for the proof of concept :D 

The DWO was glued to that radial spoked date wheel.  Which is also a rolex DWO in white rather than silver.  I use 2 part epoxy to glue the DWO.

Broaching is just twisting those tiny files in the holes of the hands.  Pretty simple to make one bigger.  Smaller is harder.  You can use a pin vise to make the sec hand hole smaller.

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ClassicWhite

Oh mate, you make things look so easy, it causes people like me to have a go and despair... Good tutorial though. 

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Jibuti

Rich... Those six years old children have 30 years experience... Never underestimate the power of yellow side, padawan... 

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RussP

Payment Sent !!

Brilliant tutorial, @NCRich

You make EVERYTHING look so easy.......................

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BIG GRUNDY

Hats off once again.

Very nice work !!!

Thanks for sharing

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tribefan
7 hours ago, RussP said:

Payment Sent !!

Brilliant tutorial, @NCRich

You make EVERYTHING look so easy.......................

He does, but this is a pretty realistic upgrade. I've seen more than one thread on RWI asking about swap outs for the 2813 with a lot of fagettaboutit answers. Here it is.

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Bill_C

This is EXACTLY what I've wanted to know about. Different watch but same movements.

I really wish I had your skill but I know my limitations. Maybe someday I'll buck up and give it a shot following your tutorial.

Sent from my SM-G955U using Tapatalk

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d4v3

Amazing tutorial Rich, i need to get my self one of those hands assortments

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ShovelnTC

Great post mate and I'll have no problem following the tutorial once I find a 400mm version as those little critters are just tooooooo small for my decrepit and unsteady hands.

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BravoDelta

Your tutorials, and others' are impressive. I've never taken a watch apart, but this makes me want to. I'd like to make one of those "vintage" subs one day. :thumbsup:

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roberto

Super interesting stuff.   If I only wasn't such a clumsy guy..

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Sifu Whitey

I really enjoyed this.  I lack the tools, facilities, skills and time to do things such as this, so I appreciate your abilities more than you know. Thanks. 

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itgoes211

Great stuff as usual, Rich!  You’re idea about the gasket has solved my issue.  

I love the Seiko movement, other than the inability to wind and the noisy rotor.  But they are bulletproof and inexpensive.  I couldn’t understand why more factories didn’t use them - maybe stem height and b/c 2813s are much less expensive for the factories.  

But anyway, you debunked the stemheight myth and solved the diameter issue with that gasket. I gave up trying to use them when I started, but you’ve sparked my interest again in a few conversion projects gathering dust on my bench.  Thank you. 

Do you notice any more or less rotor noise now with the NH35 vs the 2813?

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NCRich
30 minutes ago, itgoes211 said:

Great stuff as usual, Rich!  You’re idea about the gasket has solved my issue.  

I love the Seiko movement, other than the inability to wind and the noisy rotor.  But they are bulletproof and inexpensive.  I couldn’t understand why more factories didn’t use them - maybe stem height and b/c 2813s are much less expensive for the factories.  

But anyway, you debunked the stemheight myth and solved the diameter issue with that gasket. I gave up trying to use them when I started, but you’ve sparked my interest again in a few conversion projects gathering dust on my bench.  Thank you. 

Do you notice any more or less rotor noise now with the NH35 vs the 2813?

The NH35 is much quieter in my opinion.

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FotherMucker

I miss posts like this, thank you so much for taking the time to take the photos and share this experience.

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GC

Genius... coupled with a boat load of fiddly bits skills!!! 
 

bravo sir, bravo

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NCRich
2 hours ago, itgoes211 said:

Great stuff as usual, Rich!  You’re idea about the gasket has solved my issue.  

I love the Seiko movement, other than the inability to wind and the noisy rotor.  But they are bulletproof and inexpensive.  I couldn’t understand why more factories didn’t use them - maybe stem height and b/c 2813s are much less expensive for the factories.  

But anyway, you debunked the stemheight myth and solved the diameter issue with that gasket. I gave up trying to use them when I started, but you’ve sparked my interest again in a few conversion projects gathering dust on my bench.  Thank you. 

Do you notice any more or less rotor noise now with the NH35 vs the 2813?

I just notice you said it could not be wound.  You are confusing this with other Seiko movements.  The NH35 winds and hacks.

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Redfire1066

Nice topic and well said.  :)

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itgoes211

@NCRich  :  correct as usual, good catch, my mistake.  I was thinking if the 7s** models regarding the wind/hack issue.  It’s been over year since I gave up and put all of those Seiko projects on the shelf.  But now I’m going to order some of those gaskets and pull those projects back out... someday... too many projects still in the queue.  But it’s better than no projects in the queue I guess (I have to remember not to complain about my princess problems :)

thanks again though!

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SCShrek

See @NCRich, I do read when you lead the horse to water... ;) 

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2hot2trot

Outstanding pictorial. A pleasure to read and understand. Thanks for your time and sharing  @NCRich

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J!m

Very nice Rich, as usual!

ive noticed some of the older Seiko movements (non wind/hack) have silver date wheels with open 6 and 9.  The font looks great as you may have noticed...

Any thoughts to expand this further?

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