RailPro > RailPro Specific Help & Discussion
Problem with AR-1 (Auto Reverse)
MtRR75:
I think I have figured out what is going on.
SHORT VERSION: The problem was inadequate power to a section of rail.
LONG VERSION: As Alan suggested, the problem is NOT with loco #304 – which is the one that is stopping when #1396 crosses one of the ends of the reversing section. The problem turned out to be #1396 – the one that was not stopping. Loco #1396 has an LM3s with a Keep Alive attached, which keeps it going..
As suggested, I started watching the voltage on the HC-2. In order to do that effectively, I slowed the speed from about 25 to about 15. At first I was getting erratic results. Most of the time, #1396 was crossing in and out of the reversing track without affecting #304. But occasionally, #304 would suddenly stop (and restart) as #1396 crossed the end of the reversing track.
Suddenly, I noticed that #1396 was SOMETIMES slowing down a little as it crossed the end of the reversing track. I was able to reproduce this and watch the voltage. The voltage was dropping gradually as #1396 slowed down, indicating a loss of power, which would make #304 stop. So I appear to have a section of track that does not always deliver full power.
The first thing I did was to test all 8 possible situations where the loco could cross the end of the reversing section. (2 ends of reversing track X 2 directions of travel {in or out of reversing track} X 2 loco orientations {pilot first vs. tender first} = 8 combinations). The problem only occurred in one of these 8 situations (loco exiting reversing track, tender first, at the SouthEast end of the reversing track – near Turnout #9 – see diagram in earlier post.)
Because the Keep Alive kept the loco going until it regained full power, I was able to figure out exactly where the loco was when the voltage began to drop and where it was when it when it regained full power. This section turned out to be the point rail in Turnout #8 and extending SouthEast to the insulated junction at the end of the reversing section. Ohm measurements confirmed that the resistance between this section and the rest of the reversing track fluctuated wildly as the point rail was wiggled.
As an aside, why did the train run smoothly across this section when travelling loco first? When the loco is in this direction, the tender pickups are on the defective track rail. The two trucks are farther apart than are the 3 drive wheels that pick up power on the other side. The two tender trucks straddle nearly all the way across the defective area. When the loco is reversed, there is a longer time that the three drive wheels spend in the defective section. Also, the loco is much heavier than is the tender. So the drive wheels push the loose point rail in Turnout #8 out of alignment more readily.
Installing jumper power wires to the points and an addition power drop to the short track section between Turnouts #8 and #9 should fix this problem. I probably won’t get this done for a while, as I won’t get much train time in the next month.
Thanks for all of your help.
Alan:
Glad to hear you are solving the problem.
Yet another testament to the old adage - a feeder to every piece of rail.
The hobby world seems to have an irrational fear of wire or a misconception they can get lucky enough that power dropouts won't happen to them. But in the end, the story is always the same. Forced to go back and add feeders. It is like the old Fram filter commercial - pay me now or pay me later. Your choice.
I chuckle every time someone posts on my blog saying I am insane for having 8 feeders on a turnout. The popular word used is "overkill". Guess who has never had to lay upside down under a layout adding feeders! 8)
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