Re: Plastic plain bearing/bushing on shaft
Speaking just about the type of plastic, with no useful advice on the design, there are three plastics that seem most likely to be the material used here:
It looks like UHMWPE in the pictures. It appears to be somewhat translucent, soft and the way it frays are reminiscent of UHMW polyethylene. That would indicate a lightly loaded bearing that provided alignment and possibly a water seal, but wold not take much heat or pressure in operation. UHMW would be very easy to get and machine to make a custom bearing. (the thick flange is unusual, so custom seems likely, but that is speculative.
A blue high temperature plastic bearig material that might look similar is Techtron HPV PPS. PPS is harder to get and more expensive, but would make a good bearing.
Turcite A is the only other blue plastic bearing material that seem at all likely, but I don't remember it being around 30 years ago.
Nylons rare less likely because they swell in water and would tend to bind the shaft unless the bearing was loose when installed. Of course there are many other plastics, but blue is not a common color.
UHMW will melt, drip and burn readily if you hold a match under the scraps. No burning plastic smells good, but polyethylene is basically paraffin wax on steroids, so the smell is pretty tame by plastic standards. The bearing grade PPS would eventually char and since it is a sulfide, it will smell awful. The SO2 in the PPS smoke is toxic.
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