On Tue, Nov 24, 2020 at 10:43 AM Keith Lofstrom <[email protected]> wrote: > ... > The Youtube video guy thought the black dust was wear from > the steel band of the clutch, and he went through a somewhat > laborious but successful process to clean the dust off. > > I realized that the black dust is TONER (which is slightly > magnetic). The best way to keep it from clinging to the > magnet is to "short out" the magnet with a keeper (I used > the nose of steel pliers). The dust still clings to the > hurky magnet in addition to the pliers, but a LOT less. > I wiped off the dust with wet Kleenex. > ...
I was partly mistaken. A magnetic clutch does depend on some stainless steel powder to create more friction than the magnetic field-on-steel effect alone. While my over-cleaning did restore function to three laser printers, one of them double feeds a second sheet of paper about 3% of the time. Adding SOME of the powder back to that clutch, doubling the "no powder" friction, stopped the double feeds. My guess is that the friction changes with temperature, and the minimum necessary friction increases with paper humidity, so I may need to make more adjustments next summer. I ordered a roller repair kit, including a replacement clutch - I will use the friction of that as a reference to roughly calibrate the other magnetic clutches. Keith -- Keith Lofstrom [email protected] _______________________________________________ PLUG: https://pdxlinux.org PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
