|
New Asian copy of the ETA 7750 |
|
|
|
|
Articles -
Watchmasters Corner
|
|
Written by Ziggy Zumba
|
|
Page 5 of 7
More improvements, note the mainspring barrel, on the ETA and the older Asian models, the barrel is split in the middle. This one is a cap type, much better design in my opinion. Nice long mainspring, smooth barrel sides which is common on the 7750. It was clean, only dry, so I lubricated the sides of the barrel with special high friction grease, and installed the spring and lubricated it with oil.
Here is the balance cap jewels, they were the only ones with oil, this is what they looked like before servicing.
Balance close up
Now this is a new “running seconds at 6” model, and as such is going to suffer from the same problems as the Swiss powered one, namely asking too much from the movement by having to power all these new gears, if you remember the review last summer, the transfer of all the sub-dials requires 11 (yes Eleven) new gears.
Transfer gears are a problem…
You can see here the new gear on the running seconds, this will mate to 5 more gears before the seconds can be displayed at 6 - can you say loading down the movement…remember this is a constant load, as long as the watch runs, this load is applied to the basic movement.
1 is the cannon gear, 2 is the new gear for the transfer of running seconds (this is the shaft at the 9 sub-dial position on the movement, the 2nd wheel which is running seconds), and 3 is the minute wheel, 4 is the hour wheel…what the hour hand goes onto…
I put the movement on the watch analyzer Before installing any transfer gears and adjusted the beat and rate. Here’s what it looked like.
Then I put the bridge over the dial side and re-tested the timing and beat. This is with only 1 of the transfer gears in place. It was a mess, there is such a high load from the one gear you see here, that the watch finally stopped working altogether. That is with only one gear in place, imagine installing the next three.
So I tried to fix the problem, if indeed it can be fixed, remember this is a design problem, not a servicing one… After 4 disassemblies of this bridge and gears, oil, no oil, clean, re-oil, etc, I finally pressed the transfer gear off the plate by pushing the center pin out with my jewel press, and cleaned it really well and applied minimum oil on the slider part. Reassembled and it worked – finally.
This is the first gear I am talking about, if you note the gear under the plate – gold coloured, it’s the one on the end of the second wheel. It mates to the first of the 5 transfer gears which you see under the plate - it’s silver coloured. This is the one that had the problems, and the pin in the center of it is what I removed and reinstalled to get it cleaned up…
|
|
Last Updated ( Tuesday, 14 August 2007 )
|
Articles 
