Column wheel question...

[roadcarver]

In lamen's terms... what's so special about column wheel chronographs? Anyone care to explain?

Thanks in advance!

[SLRdude]

From Time Zone:

As one can imagine, constructing a chronograph is fraught with the potential for inadvertently stopping or damaging the entire movement. For example, if the reset mechanism was somehow activated while the chronograph was running, large destructive forces would be applied to the entire movement train, which would at the very least jam the movement, and would likely destroy several components.
The column wheel was one of the successful early designs to ensure that none of the above happened. If you can visualize the top of a castle turret, with tooth-like battlements, this is what a column wheel looks like. The pushers that control the chronograph rotate this wheel, and the various parts of the chronograph are controlled by fingers that fall into and out of the spaces between the teeth. This ensures that each of the chronograph parts is coordinated properly.

Because producing and finishing a column wheel is labor-intensive, a simpler, easier method of producing chronographs was needed to keep this complication from appearing only in very expensive watches. The most common method is to use an oscillating pinion to coordinate the chronograph start, stop, and reset (i.e. a cam shaped device that rotates back and forth as the various functions are activated.) This allows for reliable operation without nearly as much fiddling and hand adjustment as a column wheel requires, and the pinion can be built using pieces of stamped metal.

These days, relatively few column wheel designs are still being produced.

About the only remaining mainstream column wheel movements today are the Zenith El Primero, the Rolex 4130 and the Omega 33xx.
The Omega 3301 in your Seamaster is a column wheel type.

The original Speedmaster movement, made by Lemania, was also a column wheel type.
The need for a cheaper manufacturing process and less parts almost killed the column wheel design. The market is pretty much dominated by the lever type movements. Valjoux 7750 is probably the most famous one.
The Omega 5100 in the current Speedmaster Pro is also a lever type movement.

Here is a pic of the column wheel (the turret looking thing) from a Zenith El Primero.



When you push the chrono buttons on the column wheel, the turret looking thing gets moved and it engages the second hand. By contrast, on a lever type, the chrono pusher moves a series of levers which in turn activate the second hand.

About the only real life difference that one would notice between the two of them would be the speed of second hand activation once the chrono button is pushed. IMHO, the time difference is trivial, way less than a tenth of a second or even less. However, it is obvious that on the column wheel the activation is nearly instant, even when pushed slowly, while on the lever type if you push slow, the levers will move slow too.

I have/had both types, and the only reason I prefer column wheel is simply because it is the traditional way, the complicated way, and the road less traveled.

Hope this helped.

[roadcarver]

Woah, thanks Chip. This explains it perfectly...now I know why a column wheel design existed.

Regards,

Vernon

[timebroker]

Excellent explanation, copied and pasted

[SLRdude]

Originally Posted by timebroker

Excellent explanation, copied and pasted

Yes it is. Everything that it italic is copied. Like I said in my post.

[timebroker]

Originally Posted by comatox

Yes it is. Everything that it italic is copied. Like I said in my post.

I meant I copied and pasted it