Here's a bit of a head scratcher

peasant

I was just contemplating my Raketa, when something struck me ...how did they manage to display the day?

As you can see, the red dot jumps through from 1 to 7, indicating the day of the week (in this case it's Thursday) over half the face of the watch.



So the first thought is that the day wheel contains two red dots 180 degrees opposed and goes round once every fortnight, just like on a normal day/date display like here:


(except the date is at 3 here, not at 6 like on my watch)


And then you realise ...hang on ...they've got 2x6 spaces to display 2x7 dots, so in this setup there would be a red dot displayed on the 7 & 1 position simultaneously ...the first one would still be at 7 while the second one already shows at 1

And then you look at it a bit longer and it seems that the holes for the dots aren't evenly spaced either.

At first I thought this had to do with the different radius for the dot and the hour, allowing for a better match. But when you look at it, that could have been done better ...the dot isn't always 100% clearly matched with the hour number.
So it probably has to do with the necessary spacing between the dots to make the display work at all ...but for the life of me I can't figure out how many dots there are on the day wheel and how they are spaced / grouped.

Geometry experts to the front ...answers on a postcard please


(and no ...I'm not going to take the watch apart. The solution to this problem will have to remain theoretical)

peasant

bedlam wrote: »

It is most likely similar to the Ochs und Junior Settimana Junior but with out the progress window between day 7 and day 1.

The disc progresses once a day between hour marker 1 and 7 and then jumps back to 1 at the end of day 7.

Thanks, bedlam

Interesting watch, that one.

Somehow I doubt though that that's the solution that Raketa employed. This is a watch made during Soviet times, when standardisation was the way to do things. It uses the standard Raketa 2628 day/date movement used on many other models. There even is a family of watches using the same case, just different dials and day or date positions ...this particular watch being the only one with the date dots.

I somehow think that a special date wheel is as far as liberty in design may have been allowed ...I have doubts about a modified movement with a jumping date wheel.

Besides, I just ran the watch through several date changes and the jump from 7 to 1 sounds and feels exactly the same as any other jump ...I'd expect a big jump to feel/sound slightly different.

I could be wrong though ...but I'm still not taking the watch apart

ozmo

This shape seems to works perfectly when rotated ~26 Degrees each day (360/14).

So two dots - one on each side of the circle - but the dots are a little longer -
so that on Monday the dot stretches almost but not quite to Tuesday

peasant

Now that's what I like to see ...a man with a drawing

Makes sense too ...well done !

ozmo

peasant wrote: »

Now that's what I like to see ...a man with a drawing

Makes sense too ...well done !

I like puzzles...

heres the whole set of rotations - I think as you guessed yourself - the odd distance at the end is so that you dont see two dots at the same time. Clever Ruskies.

Zagato

Peasant wrote:

And then you realise ...hang on ...they've got 2x6 spaces to display 2x7 dots, so in this setup there would be a red dot displayed on the 7 & 1 position simultaneously ...the first one would still be at 7 while the second one already shows at 1

So then, this bit isn't correct as per osmo's diagrams?