I am restoring my 4T proofing press from the early 1950s and am dealing with replacing the motor belt. I bought a new one from NA Graphics (thanks, Fritz) because the old one was pretty badly dry-rotted even though it still functioned. Even with much adjustment to the height/position/angle of the motor in putting the new belt on, something about the tension/angle isn’t right because my belt keeps flying off the pulleys – literally! Fritz recommended taping the edge of the pulley to create a lip. It worked for a while, then it popped off again. If anyone has any experience specifically with doing this task on a 4-T, I welcome any/all advice. Maybe I just haven’t found the positioning sweet spot yet, but I’m losing valuable press time to this task. Thanks in advance for sharing your experience!
Thanks, Paul. Have done some more fine-tuning of the motor position and angle and it’s staying on for now. Fingers crossed!
Tension on the belt is adjusted by loosening the eight 5/16″ jam nuts on the four hanging adjusting screws that hold the position of the motor.