Instructions for Hermle Precision Regulator (One month weight driven) with movement 0761

(One weight, two ruby pallet jewels, 6 ruby hole jewels, and 7 ball bearings)

This clock requires winding once a month. The deadbeat escapement has two pallet jewels, and the movement has 6 hole jewels and 7 ball bearings. The power reserve (or maintaining power) keeps the clock running as the weight is being wound up.

This is a high precision product, therefore handle the clock very carefully and use gloves to protect the surface of the heirloom.

1) Unpack the clock

Carefully take clock, the pendulum, weight and crank out of the carton. Save all packing material in case the clock needs to be returned, or shipped in the future.

2) Hanging the clock

Hang clock at the desired place. Remove the movement holding screws (1) on right and left hand side. Wearing the cotton gloves, pull movement forward by holding the dial, and put it dial side down on a soft surface. Take off the transportation device located between movement and case. Be sure to keep the transportation device.

3) Hang pendulum

Remove the clear plastic coating from pendulum disc. Carefully hook the pendulum onto the pendulum spring (2). (Pendulum spring should not be bent.) The pendulum must now hang vertically and parallel to the backboard. Be sure that clock hangs straight. Tip of pendulum (3) should be exactly in the center of the pendulum scale (4) If not, move bottom of case slightly to left or right.

4) Insert movement again

Push movement back onto the mounting pillars (5). Pendulum guide (6) has to be positioned exactly in the slot of the part (7) which moves the pendulum. Now you can insert and tighten the two mounting screws on the left and right side.

5) Hanging weight

Hang the weight on the pulley (if the pulley has come loose from the foam block, position pulley with yoke down and put the cable around the pulley before hanging the weight). Please take Styrofoam block out of the cable after several days and save it for future use if the clock is shipped or moved.

6) Starting the pendulum

Move pendulum slightly right or left until you here a "tick" noise. Remember the position of the end of the pendulum stick on the pendulum scale mounted to the back board of the clock. Move now the pendulum slightly to the other direction until you can hear the "tock" noise. This point should be approximately the same distance from the center on the pendulum scale like you heard the "tick" on the other side. If this is not the case, adjust this with the knurled screw (8) on the pendulum stick. Turn that screw to right or left until the distance from the center of the pendulum scale to right and left is the same. Now push the pendulum to the left or right to 1 1/2 on the pendulum scale and let it swing. The "tick-tock" should be equal now. If this is not the case do the adjustments again with the screw on the pendulum stick.

7) Time setting

Set time with minute hand (long hand) by moving minute hand clockwise or counterclockwise. To synchronize time with another clock, stop pendulum and start according to second hand on the other clock. Please do not touch second hand to correct time. (The second hand makes 78 steps for one minute turn.)

8) Regulating the clock

The timekeeping is regulated by turning the regulating nut (9) at the end bottom of the pendulum. To slow down, turn regulating nut to the left. To run faster, turn the nut to the right. When this adjustment is necessary, please hold pendulum disc (with gloves) to avoid twisting of the pendulum. By not holding the pendulum, you could damage the pendulum spring.

9) Winding the clock

I recommend using a small Hermle key (the key made for movements such as the 130 and 131 movements) to wind the clock. Turn the key gently counterclockwise, one-half turn at a time, and gently release the key after each half turn. Stop winding before the pulley touches the bottom of the movement.

The original instructions call for using the crank supplied with the clock. I have found that this causes the movement mounting to flex, making the pendulum wobble. Hence, I recommend using a key instead of a crank.

10) Care and maintenance

It is recommended that your clock movement be cleaned and oiled every five to eight years depending on climatic conditions. Extremely dry, humid or salty air, heat or cold may necessitate more frequent servicing. Hermle does not recommend that you service the clock movement yourself, It should be done by a professional clock maker as you require a special oil for re-oiling the movement.

Hermle 761 movement
Hermle 761 movement