With the power released, if the watch is in beat the pallet fork will be centered between the banking pins on the main plate. It is usually fairly easy to see if the pallet fork is centered.
It is put in beat by turning the hairspring collett on the balance staff.

On some watches, it is difficult to see the pallet since it is sometimes covered up by the hairspring or pallet bridge. On this Hamilton 992b, the pallet is fairly easy to see.


You can also adjust this before putting the watch together –with only the balance installed, the jewel must sit on a line between the escape and balance jewels (and pallet pivot jewels), and if you can see through, exactly between the banking pins when looking down this line.

Getting the beat correct makes a large difference in the way the watch runs. It will start instantly when wound, and keep time in positions much better, have better balance rotation.


Movable Stud
On more modern watches, they are made with an adjustable stud — quite easy to put into beat as you just move the regulator arm.


13 Comments
Justin
Awesome. Thanks for explaining this!
Alex
What do horologists do when the near vision starts to go? I’m looking at the pictures and everything looks unbelievably tiny!! (Coming from the guy with bifocal contacts)
Thanks, just fascinating as usual.
Jack Boyd
Use a higher power loop… Once this is no longer possible, retire!
Ken Borgland
Thanks again for the info. I’m working on a ill Sangamo with that problem.
Mark Morgan
always interesting GREAT story
Frank
Great post! Very interesting. Thank you for sharing your art!
Mel Schuman
Thanks to your excellent explanation, I will look at my pocket watches more carefully.
Steve
Well. I was not expecting watch repair 101 but…I Learned something. Thanks ,for a great Post! Now I know were that jewel thing goes.Take care Mark.
Rob Tompkins
Thank you for sharing, It is always good to get a fresh perspective and pictures on watch repair topics. Keep them coming!
Manh Pham
Your blog is amazing with explanations and illustrations making it a must read for me. I have learned something very special owing to your professionalism and experience. Keep on going, Mark. Thanks.
john meisch
I’ve been struggling with the “beat” challenge lately. When you put the roller jewel as you suggest, it seems like you are making an assumption re the “wind up” vs the “release” of the hairspring. When the balance rotates CW, the hairspring is being wound tighter (incurring potential energy). When the balance then rotates CCW, the hairspring is releasing energy for some period of time—–until it reaches its expansion limit (another form of potential energy ?). I have trouble believing that the opposite contraction / expansion are identical in time.
James McLaughlin
I moved the beat regulator accidentally and now the watch has stopped.
Gents Seiko 4R36-04Y0 Turtle SRP773K1 Automatic Divers 200M
Rob
G’Day Mark,
Thank you for all the helpful hints. As “newbie” I can use all the good advice and pointers I can get!
Can you recommend a possible source for the safety roller used on a Hamilton 990 16s movement? I’m down to the point that I may actually try and turn one up on the mini lathe. The old “cattledog” (catalog) number on this minuscule piece was #391.
Rob FNQ,Au