*Convert a Ham III to a Ham IV*
By: Jaden
11 June 2007

I found what I believe is a Ham III rotor on the junk metal pile at the dump. It's identical to the Ham IV except this one doesn't have a brake. I brought it home and opened it up and was surprised to see how clean it was inside. There was a little grease gunk and other than that it was nearly clean. The bearings are in almost excellent condition and I was able to finger spin the motor easily.

For good measure I disassembled the unit and cleaned the inside of the housing, the bearings, and the track that the race sits in with carb, choke and throttle body cleaner. I removed the bearings from the plastic races and scrubbed those in the sink with dish soap and water.

Clean upper assembly

Clean bearings

Clean lower assembly

Once it was all clean, I began converting the rotor. The Ham 3 had a wire terminal connection bar on the bottom. When I put the Ham 4's braking assembly on I needed to connect the new base (braking assy base) to the "real" base of the Ham 3.

Ham 3 on left, Ham 4 on right

Wired from the terminal directly to the motor

I cut the OLD Ham 4's wires up near the motor. Then I simply sized up the brake assembly, shortened the wires (leaving plenty of extra) and soldered on ring connectors. Then I just connected the brake assembly's wires to the Ham 3's terminals. Fairly simple. Pin 1 to 1, 2 to 2 etc etc.

NOTE: Be sure that the wires are clear of the solenoid and moving parts inside the brake assembly.

Brake assembly

Junk from the OLD Ham 4

Brake assembly mounted to the Ham 3 & wired

The brake assembly bolts right on to the base. In the above right pic you can see both wire terminals.

I used white lithium grease, it's lightweight and is supposed to work even in cold temperatures...so says the can anyway.

Brake housing assembly (greased)

Putting bearings back in a race

Lower end ready to go

The guts in the brake housing

Upper ball bearings

Upper housing (track greased)

When the gear ring goes back in be sure that it's pushed down all the way, if it's not the rotor won't spin. The motor will run, but that's about it.

I made sure to grease the bearing tracks and smeared some on the bearings themselves. The bolts that hold the unit together have never seize lube on them so that they'll come out easier in the years down the road.

The thing works, spins 360 degrees w/o a hitch. Now I have a good Ham 4 rotor essentially for free!


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