Clapper box adjusting screw

This tip will prevent the clapper box adjusting screw from wearing through the 12-400289-000 Spacer. Also, the modification provides a larger flat surface, in order to help stabilize the lift rods.

The following parts will be needed for the modification (figure 1):

12-150063-000 Spring Seat Assembly
11-102262-001 Set Screw 3/8-16 × 2-3/4”
11-195016-001 Lock Washer 3/8”
11-125104-001 Hex Nut 3/8-16”

  1. Slightly thread set screw on spring seat assembly, being careful set screw does not protrude (should be slightly less than flush).
  2. Next, thread the lock washer and hex nut on set screw.
  3. Before installing in to the clapper box, be sure the parts are assembled as shown in figure 2.
  4. Lift the rods with a pry bar and install the assembled set screw/spring seat assembly into the clapper box from the underside (figure 3). Note how the original set screw shows signs of wear on the spacer.
  5. After installing the set screw, perform Ball Lift Rod Adjustment # 26, listed below.

This adjustment is made to obtain maximum ball pickup efficiency. See Page 3-30 in the A-2 Automatic Pinsetter Service Manual, part number 12-752828-000 for further details.

  1. Make sure the elevator frame (adjustment 24) and the elevator guide rollers (adjustment 25) are correct.
  2. Place a standard-size ball between the lift rods and ball elevator wheel, and manually rotate the ball elevator wheel until the ball wedges itself, lifting the ball lift rods. Loosen the jam nut and turn the adjusting screw on the clapper block until the bottom of the screw is 1/16” from the surface of the lower clapper block.
  3. Place a standard-size ball between the ball lift rods and ball elevator wheel near the top of the lift rods. Loosen the jam nut and turn the adjusting nut on the spring rod until a 9/16” (1/16 -0) gap is obtained between the rubber bumper and the ball trip bracket. Tighten the jam nut against the adjusting nut.
  4. Place a standard-size ball at the lower center of the ball wheel so it is resting against the rear ball lift rod. With the pit conveyor in its rearmost position, there should be 1/16” minimum clearance between the lower portion of the ball and the rear edge of the pit conveyor clamping plate.
  5. If the clearance is less than 1/16”, check the Elevator Guide Roller Adjustment, Pit Conveyor Adjustment, and Elevator Frame Adjustment. All adjustments can be found in the 12-752828-000 A-2 Automatic Pinsetter Service Manual. If all adjustments are correct, the ball lift rods must be raised to increase the dimension. To raise the ball lift rods, loosen the locknut on the upper clapper block and turn the adjusting screw until the 1/16” dimension is obtained. Tighten the jam nut.
  6. Check the ball lift rods to assure they are parallel with the ball lift wheel.

Figure 1

Figure 2

Figure 3