Page 5: Tape Cutting Problems

Tape cutting problems are usually the result of old, worn shears, or shears that have a build-up of glue.

Check the following areas in order:
  1. Old, worn shears
  2. Glue build-up on shears
  3. Lower shear out of adjustment
  4. Upper shear out of adjustment

A. Replacing Worn Shears

Note: Shear Kit – 600SHEARASSYKXX (Ref. FM20BXK) includes upper shear, lower shear, lower shear springs, shear rod, retaining ring.
  1. Remove water bottle and tank.
  2. Remove key drum and stop bar.
  3. Remove pressure plate assembly. This is the chrome plate that sits on top of the moistening brushes. With a hammer and punch, tap the rod that holds the pressure plate assembly. Tap from right side. The retaining ring will pop off onto punch.
  4. Remove the support rod by pulling it to the left. Remove the pressure plate and the two shear rollers.

    For the following procedures, it may be easier to stand the machine upright on the back cover.

  5. With key drum removed, you’ll see a circular cut out in the left frame. Inside the cut-out, you’ll see the rod and retaining ring that holds the upper shear onto the yoke. With the punch, tap the rod so that the retaining ring pops onto the punch.
  6. Remove the rod, pulling it to theright.
  7. Remove the upper shear by pulling it down and swinging it out toward you.
  8. Pop the two springs attached to the lower shear. These springs are attached to a pin on either side frame. The springs pop off these pins.
  9. Remove the lower shear by pulling it up through the lower tape plate.
  1. Drop the lower shear in first through the upper tape plate, making sure that it sits between L-shaped holders on each side frame.
  2. Reattach the lower shear springs to the frame pins.
  3. Slide the new upper shear in and up through the lower tape plate so that it comes up in front of the lower shear.
  4. Slide the shear rod through the yoke and upper shear assembly.
  5. Press the retaining ring onto the shear rod. This can be a real pain. Needle nose pliers cna help, just make sure you press until the retaining ring is secured to the rod.
  6. From the left side frame, start re-inserting the pressure plate support rod. Install the first shear roller, then the pressure plate, then the second shear roller.
  7. Once through the right side frame, press the retaining ring on the support rod.
  8. Reinstall the key drum and stop bar, water tank, and bottle.

B. Glue Build-up on Shears – Cleaning Procedure

To clean the upper shear:
  1. Remove the water bottle and tank.
  2. Pull the rocker stop rod on the right side of the machine with the right hand and keep in this position until the next step has been acocmplished.
  3. Reach inside the machine where the tank was removed and pull the upper shear down to swing it out.
  4. Clean the shear with foamy cleaner and WD-40 to remove all dirt and dry glue. Shaer should not be scraped with hard objects as resulting scratches will cause rapid build-up of glue.
To reinstall the upper shear:
  1. Pull the rocker stop rod forward with the right hand and hold in this position.
  2. Tip the knife up into cutting position and push upward so that the knife comes up between the lower shear and the shear rollers. You may have to slightly push the lower shear back to get the upper shear to fit between this shear and the guide rollers.
For a quick cleaning:
  1. Remove the water bottle and tank.
  2. Raise the upper shear by pushing up on the yoke assembly.
  3. The upper shear is attached to the yoke assembly by a shear rod. Push and hold up the yoke assembly shelf.
  4. Spray the upper shear with a foaming cleaner and / or WD-40.
  5. Dry it off.


Gap between upper and lower shear is wider at point B than at point A.

C. Lower Shear Out of Adjustment

The gap or space between the upper and lower shear can be adjusted to improve cutting. We have found that, unless someone has re=adjusted the lower shear, you should not need to re-adjust the lower shear. The factory setting usually does not come out of adjustment.

Adjusting the Lower Shear
  1. Life up the front cover. Remove the upper tape plate. Look down at the uppe rand lower shears with the handle back in home position. The two blades hsould only be touching on the right side. There should be a gap of approximately 1/32″ on the left side. The gap should decrease until the point of contact is reacher on the right side.
  2. Locate the lower shear adjusting screw on the right side frame. It has a washer and is located just behind the tank.
  3. Loosen the screw only slightly until it can slide up and down. To increase the gap, slide the screw up. To decrease it, slide it down.
  4. Retighten screw securely and test cutting.


Location of lower shear adjustment screw.

D. Upper Shear Out of Adjustment

Tools required: 3/32″ Allen wrench.

This adjustment should be made only if you notice that the left hand side of the tape bends over when it is dispensed. The tape will have a small bend in the left leading edge corner.

  1. Remove tape from the tape basket.
  2. Locate the circular cut out in the back wall, or vertical tie plate.
  3. Inside the cut out, you’ll see the head of a set screw protruding from the rear of the yoke assembly.
  4. Turning this screw clockwise will raise the lower feed wheel, but limit the upward travel of the upper shear, causing the tape to bend (or jam) on the left corner.
  5. Turn set screw counter clockwise about one half of a turn and try feeding tape.
  6. If it still bends at the left corner, repeat the procedure until you get a straight, even cut across the entire length of the tape.

If you can’t find the answers here, then please feel free to call us at
Email for assistance.