Synchronar cases... how many?

[SASM]

Does anybody know how many different cases have been made for Synchronars? I do not mean their finished, just the form of a case.

I guess Mark I and II look the same. Maybe we could post a few pictures, I am going to upload some tomorrow.

Thank you, Hanno.

I´ve found this threat, but I am sure there have been other versions made and I do not know how they look like:

http://www.dwf.nu/viewtopic.php?t=3296

[retroleds]

It's really fairly simple(I believe).
1. All the cases start out the same, in theory - bar across the center, rounded corners.
2. Some cases have facets/angles ground where the corner radius would have been.
3.Some of 1 & 2 don't have the center bar across the solar cells. Making them a Sunwatch.

Oh, and some have a little slot at the back for the rear setting magnet of the early models.

I think that pretty much covers it....late here, my brain is shutting doooooowwwwwwn.

[SASM]

Hmm, here´s a picture with three different cases. I do not make a difference between synchronar and sunwatch, since sunwatches seem to be synchronars with "B-class-cases".

[retroleds]

Those cases(I believe), fit what I described.
Left:: faceted/angled case, center bar intact.
Center:: faceted/angled case, no center bar
Right:-rounded corners case, no center bar

So the only other combination you don't show represented is:
Rounded corners, center bar intact?

I don't believe there is any other case design in the Synchs. I'm not a huge fan of them so I may be missing something.

[SASM]

Well, have you seen the differences between case 1+2? The sides and the edges are totally different (I still do not speak about the bars on top).

[Sully008]

Well, have you seen the differences between case 1+2? The sides and the edges are totally different (I still do not speak about the bars on top).

There has been at least one "unfinished" case for sale on eBay by Barry Riehl, it was an angular case that didn't have the "angles" done. Your case on the left might've been one of those, although it doesn't look quite like the one Barry had. AFAIK, the second from the left is a correct angular case.

[retroleds]

Ok, your center one is a slight variation on the left one - it has the additional angle on the corners(little hard to see the black case clearly). And the left and center have a flat top, the right one has a slight angle to each side of the top(evidenced by the up/down "lip" shape of the front facet). So maybe 8 possible variations? I was just looking at the cases I have here - the machining is so bad on some of them, it almost makes me wonder if the tops with the small angle to surface around the solar cells were primarily just an attempt to save cases that were a little warped and had insufficient metal to be machined for the truly flat top. It's a drop of less than .5mm from the center of the top to where that flat runs into the next one(around switch), but it sure could hide a lot of sins from a machining standpoint. According to legend(from R.R.'s sons), the Sunwatch design came about due to spoorly formed center bars on a batch of cases. They cut out the bars and Voila! a new design. THEN they ordered some flat module tops.

Obviously all the designs could be final machined from the same basic casting. Cast them square cornered, then machine externally for the variations.

[charger105]

Well, have you seen the differences between case 1+2? The sides and the edges are totally different (I still do not speak about the bars on top).

There has been at least one "unfinished" case for sale on eBay by Barry Riehl, it was an angular case that didn't have the "angles" done. Your case on the left might've been one of those, although it doesn't look quite like the one Barry had. AFAIK, the second from the left is a correct angular case.

I agree with Mick. I believe the one on the left is an unfinished case (the front corners haven't been ground down yet).
In fact I've got a case where one front corner is ground down, but the machinist went too far and created a small 'hole'. The other corner has been left as is. So it's a combination between your left case and the middle one.

Rgds.

[SASM]

Thanks for your answers. Howard also told me that this would be an unfinished case. I still don´t believe it for these reasons:

1.) The angle of the side area (with the holes for the sliders) is completely different. You could never bulid a case #2 out of a case #1 if you would have flattened the corners. The cast seems to be different.

2.) The holes for the sliders are milled and of course you cannot mill sharp "inside" corners. A few other areas are milled, too.

3.) As retroleds stated the 1st case has a slight angle on the top. It makes no sence to produce a mold with a top angle if you want to have a flat top.

4.) There´s no hole for the back slider of a Mark ! and II, so this case cannot be made out of a Mark I or II case.

Anyway it seems that there were some test cases produced, I guess the 1st case is one of it.

[charger105]

Another thing to think about is the recess around the display at the front of the right-hand gold one. I'm pretty sure this recess is cast, not milled.

The angled corner cases don't have this recess. In fact, from memory, I don't remeber seeing any casting marks on the left-hand style angled ones. Perhaps they were completely milled from a solid billet of SS ?

Can you even cast SS ?

Rgds.

[retroleds]

2.) The holes for the sliders are milled and of course you cannot mill sharp "inside" corners. A few other areas are milled, too.

There are a number of ways to make sharp corners for a thru hole like that. Being a former toolmaker, I have done both of the two most common.

First possibility - broaching. A broach is like a precision file that gradually gets larger, until the last teeth cuts the final shape to size. Many car parts are broached to fine finish dimensions - e.g.the smooth pockets where a universal joint gets bolted onto a cast(hot forged?) iron driveshaft end. Broached, not ground. You can even do broaching using a manual arbor press if necessary. Mechanical watch dudes broach many holes to final size.

Second possibility(totally being done back then) - electro discharge machining(EDM). You grind a solid carbon blank to .0015(english/standard) smaller on all dimensions than your holes and the machine can burn precision holes burn through that material in 5 minutes. Faster if already roughed in. I was the (sorry if offensive) "carbon nigger" for the shop I was at for a few months. Finally had to threaten to quit if they weren't going to rotate people. It is such a messy job -imagine grinding pencil lead into complex presicion forms all day. EDM is extremely cheap today, as it has been surpass by other technologies.

Answer to question - yes, you can cast stainless steel. I would agree that some of the cases are poorly cast and angles are frequently off or different sizes. Again, I think some poor slob was expected to clean off the casting scale and they chopped those angles on top and at other placed to saves cases that wouldn't make the cut otherwise. I have to wonder if Roger senior didn't supervise or otherwise handle the finish machining of his cases.....his sons have told me he liked doing a lot of his own machining on watches and other things. Not many people know the RR had a business that ground out and refurbished brake drums. Or that he dabbled in machining his automatic transmission valves bodies for different performance/function.