I own a PRC4 and agree with everything Doug just wrote. The arm can be lifted straight up and out. It takes some force because of the magnet pulling it down. The brass collar around the base of the arm remains on the deck. My counterweight is attached to the armtube with a locking set screw that can be loosened with an allen wrench. I can't remember if it is Metric or English.
I put a tiny film of Vaseline on the magnet under the arm. It seemed to help with the movement across the LP. I have set my VTF to zero but I still occasionally get a small bundle of thread at the suction head of the arm only when it is moving from the LP label to the outside, not when it goes from the outside to the label.
I do a double suction when removing the water rinse by starting the arm at the outside of the LP. It moves to the label, then I pick up the arm and place it on the other side of the spindle at the label and it continues to the outside of the LP. This assures that it is absolutely dry.
I placed a small rubber washer on top of the spool of thread to keep it from rotating during use. I also put plumber's thread tape on the threads of the glass jar. This helps with air leaks and increases suction pressure slightly.
Congratulations, it's a nice machine.
I put a tiny film of Vaseline on the magnet under the arm. It seemed to help with the movement across the LP. I have set my VTF to zero but I still occasionally get a small bundle of thread at the suction head of the arm only when it is moving from the LP label to the outside, not when it goes from the outside to the label.
I do a double suction when removing the water rinse by starting the arm at the outside of the LP. It moves to the label, then I pick up the arm and place it on the other side of the spindle at the label and it continues to the outside of the LP. This assures that it is absolutely dry.
I placed a small rubber washer on top of the spool of thread to keep it from rotating during use. I also put plumber's thread tape on the threads of the glass jar. This helps with air leaks and increases suction pressure slightly.
Congratulations, it's a nice machine.