Daley Train Log
Page 95
Yesterday, while I was carrying out a series of switching moves with the S-4 diesel switcher CN 7985, I noticed that "the diesel locomotive would often stall, particularly when it was over a switch. The locomotive runs well when it has some speed, but it had a lot of difficulty running at slow speed over many of the switches in the yard. Part of the problem was caused by dirty track, but there were still problems after I had used the Bright Boy eraser on the track. I think the wheels on the locomotive are clean - I watched the fellow in Calgary clean them when he was installing the decoder last week. but there may be problems with some of the track connections as well as with the overall levelness of the track. I may also need to solder more connections from the main track bus to the switches to ensure a clear signal. This will involve much more work but is also not a problem. The fact that the locomotive runs well on mainline track suggests that the problem has something to do with the track connections in the yard."
Then this morning I considered the problem again:
" There is a definite problem with running my S-4 switcher locomotive in the area where there are multiple switches. I think this may primarily be a combination of dirty track, weak electrical connections between sections of track, and slight differences in elevation of some track sections. There may also be a problem with dirt on the wheels of the switcher.
I can eliminate the last possibility by running the locomotive forward and back at the lowest possible speed setting on a section of flex track near one of the terminal track sections. I am pretty sure it will run just fine, but this would be the definitive test.
I now have 3 diesel locomotives running on the layout under DCC. However there is a difference in the sound level of the two locomotives with the Loksound decoders in them when compared with the one that has the Quantum QSI decoder. I would like to increase the level of the two Loksound decoders. I think this has something to do with a CV (configuration variable) but am not sure."
Now for today. I began by running my other diesel locomotive, the GP7, CN 1706, over the track in the Coaldale Yard that involved the multiple switches. It worked just fine, even on the slowest possible speed setting. This immediately told me that the problem I had with the S-4 switcher was with the locomotive and not the track.
It took me almost an hour to figure out how to remove the plastic shell from the front of the locomotive. It turned out that there was a tab on the front of the shell that would release if you simply pressed the front of the shell in. Easy when you know how. I kept thinking that there would be two tabs, one on each side of the shell (I had seen this before on a couple of my locomotives), but no matter how I pressed, I couldn't get the shell to loosen.
I then ran the locomotive over the track, watching to see if there was any pattern to when it would short out. This took another 2 hours as I cleaned the wheels on the locomotive with rubbing alcohol and then tried it again. It seemed to make a small difference but it was still shorting out. There was no pattern to where it would stop - sometimes on a straight section of track, sometimes on a switch. The problem was more severe at slow speeds, and it would disappear at high speeds. I just had to touch the locomotive and it would start up again, but only to short out within 5 - 10 seconds. I couldn't find any regularity to the problem. Sometimes it seemed to be simply when I changed a setting on the controller such as turning the light or sound on or off. Really weird. I was beginning to think that the decoder was faulty, but it still acted like a short circuit.
I then carefully examined all of the wires to see if any of them were loose, or even touching something. Once again, nothing obvious was noticed.
I then noticed that there were brass brushes that were touching each of the wheels. This is how the current would be transferred from the wheels to the motor and the decoder. Then my first break. I noticed that one of the eight brushes was bent so it wasn't touching the wheel properly. I fixed that and tried again. It seemed to make a difference, but then it shorted out again. Not as often as before, but still problematic. I was so sure I had found the problem. I took another careful look and then noticed that the brushes on one side were protruding very slightly more from the frame than those on the other side of the trucks. I tried to see if they would move and they did. So I pushed them back against the frame and tried again. Total success! The brushes were shorting out against the frame of the locomotive.
I finally put the shell back on the locomotive and ran a test run in the Coaldale Yard. Everything worked perfectly, even at the slowest speed. There was no problem going over any of the switches. Plus there was an added bonus. The sound of the bell and horn was now about twice as loud as before. It seems that the brushes were only allowing half the power to the decoder. So now everything is working. I put about 4 hours into this today, but it was worth it.
I now have all three locomotives working and am ready for another running session (tomorrow). I do not have a problem with my switches or track in the Coaldale Yard.
However I now want to begin working on setting up some controllers on the facia of the table that holds the Coaldale Yard so I can control the switches in the yard by simply pressing a button. I have verified how this will work. Now I need to build a couple of panels to hold these controllers and then install and wire about a dozen such switches. This same approach will eventually be used for the remaining switches on the layout. There is some serious work in front of me, but the thinking part has been taken care of.