HELLO PEOPLE, I ONCE TOOK A PART A 8AH AND BROKE THE HAIRSPRING TAKING THE BALANCE OUT NOW I WAS LOOKING FOR TIPS INSTALLING THE BALANCE COMPLETE BACK INTO THE MOVEMENT AS NOT TO GET THE HAIRSPRING CAUGHT ON THE CENTER WHEEL...IF ANYONE HAS ANY HINTS OR TIPS ON DOING THIS PLEASE LET ME KNOW THANK YOU AHEAD OF TIME
If you have not successfully done this before, I would heartily suggest that you find a good jeweler to do it.
If you are destined to do it your self, you MUST use a loupe or magnifier and a good light source. Pickup the top of the balance cock with a pair of tweezers, one point of the tweezers through the balance cock screw hole and the other point along the side of the balance cock. Lift up the entire assembly gently and let the balance wheel dangle from the hair spring. Moving the balance cock towards its location on the lower plate, noting the position of the guide pin in relation to the hole for the balance cock on the lower plate, gingerly slip the balance wheel UNDER the center wheel. Guide the balance wheel staff pivot into the lower balance jewel. With luck, the roller jewel will engage between the forks of the pallet lever. Lower the balance cock onto the upper pivot of the balance staff. and CAREFULLY seat the locating pin on the bottom of the balance cock into the corresponding hole in the lower plate. Look through the loupe and make sure that the upper pivot of the balance staff is in the upper jewel. Give the balance wheel a slight push and it should rotate freely through about 270 degrees of arc. If not, see where it binds and correct. It might be not seated in the lower jewel, or the roller jewel may be to the outside of the pallet lever slot. If all went well, gently screw down the balance cock, making sure that it is sitting squarely on the lower plate.
And Bob's your uncle!!!
Not responsible for unforeseen tragedies.
I could never walk anyone through this , no matter how detailed an explanation. This is something you just learn through trial and error. Usually more by error and failed attempts. This is now an easy job for me, takes maybe 10 -20 minutes if I have the parts. best of luck, the first succuss spurns the motivation to try another.