Timing machine for use with Detent escapement

[watchwldr940]

I just overhauled my Hamilton Model 21 and was wondering if there is a way to use a timing machine to bring it to time. I have a Witschi and an old but reliable B-200, but neither of these seem to pick up this type of escapement. I only have watch holders for these machines, so I don't know if a clip type pickup would work. Any thoughts? Thanks. George

 

[doug sinclair]

The B-200 will certainly recognize the 14,400 bph escapement of the series XXI. Of course, the lead with the alligator clip works better than the watch holder pickup.

 

[watchwldr940]

Thanks, Doug. It does, indeed work. Also, after actually reading the instructions with the Witschi, that machine works as well. The alligator clip would be better, though.

 

[doug sinclair]

The XXI is 4 bps, or 14,400 bph. A lot of modern watches are 8 bps, or 28,800 bph. So modern timing machines will recognize most mechanical or electro-mechanical watches. Even Accutron.

 

[DeweyC]

The most accurate machine measure of a chronometer is at 7200; which is the number of times the EW unlocks per hour. Using 14400 is unreliable because the trip spring is not a reliable sound. The most accurate measure is against network corrected time signals over a period of days.

 

[watchwldr940]

Thanks for the advice. I guess I was out-thinking myself because I was thinking that the machines might not recognize the different type of tic produced by the detent as opposed to the lever escapement. But the Witschi can be set up to record the rate of this escapement and the Vibrograph picked it up too. All is well, and the chronograph is performing very well, both "on paper" and by comparing with a time signal. Again, this MB is a wealth of information, and "Thanks" to all who keep it that way! George