Hey guys, Ladies included.
I’m building up an Athearn dummy into a powered sound unit. Supposedly it’s a GP 40-2?
#3 Should the fan be over the hole in the shell? I am assuming the rear fans are exhaust fans and the diesel exhaust would not effect the cooling fans.
Thanks in advance.
Lee
Exhaust is toward the front, fan is toward the rear. That is a dynamic brake equipped unit. I believe that they also came without dynamic brakes, so that inset you have would be replaced by a piece that had exhaust only.
Don’t know what the hole is for, but as far as I know that compartment is just a piece of the shell structure that allows for swapping out the dynamic/non-dynamic brake pieces without the shell structure collapsing.
The compartment is for ballast. My Athearn exploded view shows three steel weights fitting inside the compartment. The cover is the dynamic brake housing and the single fan cooling the resistor grids used to convert electricy generated by dynamic braking into heat. The fans at the end of the long hood are to cool the engine radiators.
Your photograph differs from my exploded parts diagram to the point that I cannot tell you which way the it should go. The Athearn drawing shows the fan, TWO small stacks, a medium sized doohickey, and a large hatch. The large hatch stretches clean across the hood from one side to the other. I don’t see that large hatch in your photo. In the Athearn drawing the large hatch goes next to the cab.
The diagram is somewhat generic since it applies to the 38-2, 40, and 50. In the real world that compartment is the dynamic brakes, the detail piece includes the dynamic brake fan as well as the exhaust stack and the tiny bit is the engine vent.
2 small stacks with the fan in the middle and a hatch in front is a 38-2, the GP40 and GP50 are turbocharged adn have a single larger exhaust stack at the front - cab end, with the fan in the middle, and the smaller engine room vent behind the fan.
The 3 fans at the rear are the radiator cooling fans.
–Randy
You have it oriented correctly. The wider of the two rectangles is for exhaust. The single fan is a dyanmic brake fan. The rear fans are to draw air through the radiators.
Be sure and clip those truck tabs which conduct electricity to make them shorter than solder some stranded wire to the remaining section. This will allow for some bigger speakers in the rear. You might be able to use a Bass Reflex with the ends cut off? Also, I solder a wire to the other side of the trucks to avoid using the frame as the frame/truck interface can sometimes be a problem. So I end up with 2 wires/truck for the best conductivity.
Richard
If you are going to hard wire the chassis, go to your local hardware store and build some 1/4" Fastons. They will slide nicely over the springy metal strip that comes up from the trucks. Look near the electrical stuff like ring terminal lugs. Benefit of the Fastons, they slide on and off allowing you to take the locomotive completely apart without cutting and soldering wires. And, the metal the springy strips are made off doesn’t solder easily.
Thanks to all.
You have answered with a lot of information that I can use. [bow] Now all I need is longer drive shafts. They will work fine, I’m sure but the shafts are extended more than I would like. I was hoping to get them from my LHSs’ junk drawer but no luck.
Thanks everybody.
Lee
What I did to extend the shafts in a Stewart U25B was to cut the shaft midway and put in a piece of heat shrink tubing with just a small drop of super glue gel on each of the cut ends.
Lee,
I use the NWSL driveshaft kits a lot of times. http://www.nwsl.com/motors-power-drives/shaft-couplings-driveline-universals
Your flywheels may be made for hex drive, be sure and confirm that first. If that’s the case I use ones from Kato. You can modify these with various materials of tubing for length. These types of driveshafts are really superior in that they have fewer moving parts and are therefore quieter. Athearn’s newer drive systems use this as well, so you can call Athearn parts group and get the codes for those if you wish. The hex end of the shaft goes in and out of the flywheel as the truck turns. For ecample I beleive 48060 is one for an SD40-2 Athearn.
Richard