Cutters have been installed on the head (See article: Installation of cutters on a finger joint head) and now it’s time to post the cutter stacks and tighten the nuts to the specified torque value. The set-up stand must be bolted to a stable workbench.
1) All nuts and washers should have been installed with anti-seize compound. Nuts should be no more than finger tight at this point. Do not allow anti-seize to get between the cutters or cutters and top plate and bottom surface of the heads.
2) Rotate all the cutter stacks back toward the center mast of the head before placing the head on the single-post set-up stand. The bottomed-out stacks will allow maximum clearance between the cutters and the alignment posts when lowering and lifting the head into the posting position.
3) Verify that the alignment pin/torqueing pin is placed in the center position. Use a rubber band to hold the “L” pin in place. There are three locating holes drilled into the bottom plate of the set-up stand. The center hole is for aligning the cutters. The left and right pin locations are for torqueing: the left hole for right hand threads with clockwise rotating heads and the right hole for left and right hand threaded bolts with counter clockwise rotating heads.
4) Slowly lower the head onto the mast of the set-up stand. DO NOT DROP the HEAD. Verify that the “L” pin is safely inserted into the machined recess of the bolt head.
5) Lightly position the cutters against the alignment post from the top of the stack downward. If the cutters are difficult to move, it may be necessary to loosen the nuts on the adjacent bolts. It can also be helpful to use a pull up tool to rotate the cutters up to the alignment post. Do not use excessive force when positioning the cutters against the alignment post, as distortion of the post may result.
6) As each cutter stack is aligned against the post, lightly tighten each nut with a wrench. Grip the head of wrench to avoid overtightening. Note:cutters may roll away from the alignment post on heads that rotate counter clockwise with right hand threaded bolts. Using left hand bolts on CCW heads will eliminate this as the cutters are rolled toward the alignment post when tightened.
7) Once the stack is lightly tightened, remove the “L” pin from the set-up stand, rotate the head back away from the alignment post, then lift the head to rotate to the next knife stack. Replace the “L” pin and repeat this procedure until all the stacks have been properly aligned.
8) After all cutter stacks have been positioned against the alignment post and the nuts lightly tightened, check all cutters on all stacks for rollback. This is a time-consuming process with a single-post stand, but a thorough check will reduce the grinding time required to clean up all cutters. The best way to determine rollback is with a .002” (.050mm) thick piece of shim stock. The shim should be cut to a point approximately 0.040” (1mm) in width so each individual cutter may be checked. If the .002” (.050mm) shim can be inserted between the cutter and post, the cutter is not posted correctly and must be pulled against the alignment post before proceeding. Loosen the nut, repost the cutter and recheck the stack.
9) When all cutter stacks have been checked, rotate the head back away from the alignment post, insert the “L” pin into the proper torqueing hole and secure with a rubber band. Do not torque bolts with cutters against the alignment post.
10) Torque all nuts to 25 ft lb (35 Nm) in a crisscross pattern.
11) After the initial torqueing to Rotate the head to back to the posting pin location and recheck with .002” (.050mm) shim as outlined in step 8.
12) Reposition any rolled back cutters against the alignment post.
13) When all cutter stacks have been checked and corrected, reposition the head on the torqueing pin and proceed with torqueing in a crisscross pattern in 50 ft/lb (70 Nm) increments, up to the required torque.
14) A minimum torque of 150 ft/lb (205 Nm) should be applied to 3/4” bolts with stack heights below 1.500”. As stack height increases, torque must also increase. Do not exceed 250 ft/lb (340 Nm) on 3/4” (19mm) bolts.
15) When all bolts have been torqued to the proper value, repeat the torqueing sequence one final time.
***Always have your torque wrench calibrated at least once every year.
***Always use a breaker bar to loosen the nuts- never use a torque wrench to break nuts loose.