Thursday, February 16, 2012

Get Out And Get Under

The second contactor box under the 36 opens up towards the center of the car, and it faces the row of grid boxes. As a result, it's not very accessible, and work on it is more difficult. But we won't let that stop us. And note that the open cover serves as a convenient place to store our tools!


This box is designed for five contactors, whereas the one I did first only has three. It also has more wires emerging from the back of the box.



As long as we're down here, look up at the floor above us. Although the car was built without a toilet compartment, one was later installed, and then removed in 1946. That location is now where a branch pipe goes up to the emergency valve, located under a seat.

I might also point out that all of these wooden contactor boxes have a layer of canvas on top, to protect them from blowing rain and snow. That's true on the 309 also. We don't run the cars in the rain, so I don't plan to do any replacement of the canvas. It still looks more or less watertight.

I also tightened up the truss rods. They were both quite loose for some reason, probably associated with moving the car at some point. With some magic Kroil and a crowbar, adjustment is easy. You can easily gauge the tension in the rod by hitting it with the crowbar and listening for the resonant frequency. It helps to have perfect pitch-- I prefer to tune the cars in D major.

OK, it's time to get back under. After a few hours of work, here's the completed installation of the new insulation.

I also walked out to check on the 321, and attached a couple more straps. I figure that if nothing else, all these straps are helping hold up the truss rods.

Another thing to notice is that some of the motor leads have solid connectors on the ends, while others are just bare stranded wire, as seen here. I don't know why this is. I decided to try soldering a copper sleeve onto one of them as a test. This should provide better conduction at the junction point.




It's hard to solder here because the heavy cable conducts heat away rapidly. I probably need to find a bigger soldering iron.

5 comments:

Joel Ahrendt said...

I'm actually glad I don't have perfect pitch. I do have relative pitch and tonal memory.

Anonymous said...

Can you get the stranded wire clean enough for proper solder wetting even with sufficient heat? It looks pretty dirty and oxidized from the photo.

Randall Hicks said...

That's another good question. Walt Stafa suggested using a solder pot, but using one in this confined area sounds dangerous, especially if it's being handled by a klutz like me. Then I've thought about serving new ends onto the old cables, but serving takes a lot of work too. So I don't know.

Anonymous said...

would a properly crimped lug do better than trying to solder in such a confined space?

Bruce Duensing said...

The only problems with lugs is that they can present a fire hazard if they come loosened. I would shy away from that, especially in a application that gets jounced and vibrated.