Atlantic Driver Fix and other mods
Gaylord Mann got an Atlantic, and as often happens, the plastic crank pins on the rear driver were damaged. Here's how he fixed them.
Pictures and text courtesy of Gaylord Mann
The original plastic crank pins are approximately .227 in diameter. They are also tapered. I machined them off at the face of the wheel and drilled the wheels to .200. You can see the 2-56 screw in place with the new crankpin in this view.
Here is the new crankpin on the right side. It is made from .250 diameter brass rod. The pin is 13/16" long with a smaller diameter slightly over .200 about 1/4" long on the inside for a press fit in the wheel. This gave me a shoulder to act as a stop when I pressed the pin in. It went in very tight and there is little load on it so I expect that it will last. The pin is 9/16" long from the wheel, same as the original. The end of the pin was drilled 3/8" deep with a #51 drill for a 2-56 tap. I then notched the end of the pin on the same angle as the original in order to mate with the valve gear crank. The holes in the connecting rods are .250 so they slipped right over the pins with no modification required.
The previous owner did a great job adding metal wheels on the front
truck and also on the tender. I don't know what brand, but I'm sure glad
that he did this since it saved me sourcing them somewhere.
This is the rear tender truck with brushes added for power pickup.
The original owner had used brass wire but I changed to strip brass
which stays in place better. I also added one pound of lead in the tender
and 4 pounds in the engine. With the 24 ounces that came from the
factory that gives a total of 5-1/2 pounds. Now I can pull some cars!
I mentioned earlier that the four wheel brushes were not working.
I removed them and replaced them with phosphor bronze wipers.
The wire doesn't show much but I'll paint it black when I get back
on this project. It works perfectly. The new weight holds the wheels
down and the brushes feed power nicely. I use straight DC from a
dual power pack that I built about 20 years ago when I changed to
G scale. It's built around LM338K voltage regulators and provides
5 amps of filtered DC from each side.
I love backup lights on steamers. I turned this one out of a
5/8" brass rod. The bill is sheet brass. I used a bright white
diode with a 470 ohm coupling resistor. Being a diode, it only
comes on when backing up which was what I wanted. Eventually
I'll add grain of wheat bulbs in the marker lights front and rear
as George Schreyer shows on his Atlantic site.