Converting eta 2824-2 to 2836-2

[Timelord]

Has anyone tried to replace their eta 2836-2 with a 2824-2 by Interchanging the seconds wheel, hour wheel, canon pinion and date wheel from their 2836-2 onto the eta 2824-2 so that it will fit into the case made for the 2836-2?   It is to hopefully adjust the height of the 2824-2 so stem will be in line with opening!  I would have thought that  using the dial spacer onto the modified 2824-2 would compensate for the Extra .45mm stem opening position?  Just curious as I have a low mileage 2824-2 and a dud 2836-2 with these unmolested  parts on it
thanks!
 

 

 

 

 

Edited August 22, 2020 by Timelord
Grammer errors

[automatico]

I put a swiss ETA 2824/2846 combo movement together for a JMB '1016' and it worked fine.  I used all the 2846 train wheels/escapement etc with the 2824 plates and did not even change the shock jewel assemblies to match.  The 2824 had Incabloc type and the 2846 had Novodiac type.  I left the balance assemblies as is with their original balance c*cks and just swapped them on the plates.  A 2824/2836 combo movement is the same type of swap.

 

I used the 2846 wheels, CP, SS pinion etc in the 2824 plates so the hour and minute hands would have more space between the dial and hands. 

Btw...it is the best running ETA I have.  I wore it last week and it gained 4 or 5 seconds in 4 days...it beats any genuine rlx mechanical watch I ever had.

[Serafino]

I've puzzled over related issues so much that I can't resist taking a stab at this.  Automatico you may now laugh at my hypocrisy 

 

I have almost no knowledge about these things, so leaving aside parts compatibility, and assuming this is one of the details that is the same on Sellitas, the dial spacer on both the 2836 and the 2824 is .80 mm, so my GUESSES are:

 

-The stem height difference is reflected in the mainplate design;

 

-You'll need a way to space the dial from the movement;

 

Presumably your 2836 came with height 4 cannon pinion etc. so that will span the gap.  Probably the date wheel will also?

 

What case you have matters.  In the Rolex world some modders put 2836 movements into 2.15 mm stem height gen cases using a little trickery, so you want to be sure what you have.

[Timelord]

An update!  Something is not right in my conversion!  I still find that with the right CP seconds wheel and taller hour wheel, the stem opening is presenting some problems!   I guess that there is something in the main movement plates that make or break that 0.45mm difference!  However I do recall someone here many moons ago make a 2824 movement work well in a 2836 case!  Not sure what happened!

[automatico]

"I do recall someone here many moons ago make a 2824 movement work well in a 2836 case!  Not sure what happened!"

 

A stock 2824 is thinner than a 2836 from the stem centerline to the top edge of the dial with or without the day of the week works/dial spacer because the main plate is thicker.  Because of this there will always be trouble when swapping a 2824 into a precision made 2836 case.  The 2824 dial will need a spacer on the front side the correct thickness to work properly in a 2836 case...thicker dial spacer etc.  Spacing the dial away from the movement usually calls for taller H wheel, CP, and SS pinion on a 2824. 

I see cases for sale claiming they will accept a 2824 or 2836 and they must be sloppily made inside. 

 

I have made movement spacers out of brass that hold the movement in the case using case clamps/screws while at the same time being made tall enough to raise the dial up the required amount on a dial seat made on the spacer.  This also does away with the flimsy stamped metal ETA dial spacer.  This is one solution but you need a lathe to make the spacer.  I use thick brass flat washers to start with.

 

Best solution is to use a 2836 in cases made for 2836.  Sad but true.

[Timelord]

Thanks A,

 

I recall someone here many years ago attempting this exact conversion and gave details in their method for doing this just using a hybrid of both the  Xx24 and xx36, but could not recall who it was!  Checked the archives  but could not find an anything  on this.  I vaguely recall It could have been The Zigmeister or Jackjo but cannot say for sure!    Never the less I really wanted these base plates of the 2824 because of the incabloc setting on the ebauche plate as my 2824-2 has both setups including the hair spring as well , so I could do away with using that horrible novodiac spring On the 2836-2 during servicing!  Thanks for your input!

[automatico]

"... so I could do away with using that horrible novodiac spring On the 2836-2 during servicing!"

 

The novo keeper is pretty bad but with a home made tool and a little practice they can be 'outed and inned' easily.  I have made r/r tools for them out of peg wood and plastic with the peg wood being the easier one to make of the two.  Peg wood is hard and does not splinter like toothpicks etc so it works Ok.  Sand down a point on a piece of peg wood and then sand it flat on the end just a little bit smaller than the novo clip OD so it will go down in the jewel setting and seat against the clip.  After the tip is sized, make an indention in the center of the tool so it will push down on the clip instead of the jewel.  It is easy to make the indention by pressing the peg wood against a small rounded point of some sort.

After the tool is made, practice r/r the clip a few dozen times and it will become easy to do.  From my experience, using metal tools can put the clips in orbit.

 

Here is a 'cheater tip' to make it a little bit easier/safer...clean, oil and replace the balance-c*ck jewels/novo clip first with the bal-cok screwed down tight with the main plate novo clip and cap jewel removed (after the plate etc has been cleaned if needed). 

Q...Why remove the main plate side clip and cap jewel? 

A...This prevents the balance staff from being jammed down against the cap jewel on the other side while when dikking with the novo clip making it easier to install the clip on the bal-cok side.  Novo springs will absorb a little pressure but not much at all...it is fairly easy to break a balance staff or crack a cap jewel when you get mad and press down too hard when screwing with novo clips.

For the main plate side you can very slightly loosen the bal-cok screw to give some slack. 

I do not know what a 'purist' would say about this method but it has worked for me.

 

The Bergeon 31081 novo tool is metal with notches in the tip but it is $35 or so and the home made tool works Ok for occasional use and does not scratch the clips.

This does not mean I worry about scratching novo clips.  Ha!   

[Timelord]

Thanks for the tips!  Still sounds like a climb to Everest in comparison to just opening up the lyre style spring and be done with it in a blink!

 

i made my tool from a piece of lollipop plastic stick similar to a straw which measures exactly 1.4mm and also made three  indents like the original tool.  I always shivered when removing these novodiac spring!   I still have springs somewhere in my carpets, skirting board gaps and God knows where else!  I bought a few of these before the swatch parts curfew and now do not have any spares for me to risk losing!   In fact I have a non working new mvt just because of a missing spring! The genuine eta has 3 open gaps in contrast to the clones and they can be very tedious to play with especially on the dial side where they are not easily seen!
 

As you mentioned, the other evil to deal with is breaking the balance staff!  I always removed both end stones, doing the balance side first and then removed the balance rooster to do the dial side!  It took me lomger than servicing  another movement to do it right!  Maybe it’s just me that I could never really master it!   My solution is to avoid any eta with novodiac springs altogether and  I usually buy non working rusted eta movements with the incablocs just for the incablocs Main plates alone and use my new parts in this plate for assembly🙂