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hamfest rotor:


I was expecting bad news inside this hamfest special, but it actually looks really good inside. There looks to
be a mix of thick brown grease on the mechanism and ring gear, and white lithium grease on the bearings. All
the grease looks new, and they weren't shy about using it. The brown grease on the gears is pretty viscous
though, and is caked on the reduction gears, including on their sides. I think these plates are rubbing on their
sides with each other, and is the reason the motor is slow and sometimes stalling. I think all that needs is
to have the excess grease removed and the motor will be working fine again.

The white lithium grease on the bearings looks fine as-is. There's a lot of it, but that won't hurt anything.

The position resistor looks like it's been replaced, and is in like-new condition. I don't see any reason for
the needle on the control box to be stalling and skipping around. I was getting this initially even when I was
manually turning the pointer in the rotor. There were patches 1/4" long or more where the meter just wouldn't
move as I was turning the pointer. It wasn't losing contact, since that would have caused the meter to fall
to zero. It was just sitting there as I moved it over the wiper, which defies explanation.

The wire plate on the bottom is in good shape and mostly rust-free. The screws were a little rusty, but after
some time in a tray of evap-o-rust they're looking nice again. This rotor is one of the newer models, with the
newer brake design that uses square notches in the housing and a square notch on the end of the brake solenoid.
Both the solenoid and the housing are in excellent condition, with no signs of wear or damage from slipping.
Overall the inside looks pretty clean too.

The bottom is stamped "H IV" which I suppose means it's a Ham-4. One other issue I discovered is that the motor
mounting brackets are loose, so the motor itself (with positioning resistor on top) can rock side-to-side about
1/8". This is one other reason the motor may have been stalling, if the teeth were un-meshing and binding. It
wouldn't be what was causing the needle to stall though.

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