How are the points being set? And how are the point rails powered? I mean, that may cause a difference between entering and exiting scenarios.
Cid (Memphis, Tennessee)
rrinkerThis could indicate something like the issue of one feeder crossed
if it is adjacent to a gap, either it always causes a short when a loco bridges the gap it's adjacent to or the loco stops on it when approaching from the opposite direction, not at the gap.
CPbuffwhen the loco goes over the gap (Gap B) to leave , it stops
does "goes over the gap" mean
what happens if the reversing section turnout frog and diverging rail up to the gap are powered and the turnout is not thrown correctly when exiting the reversing section
greg - Philadelphia & Reading / Reading
Are the gaps in the rails straight across from each other?
A track diagram would help. If it's a diagonal cutoff type of reverse loop, is the train entirely within the reversing section before crossing the exit gaps? That would definitely cause an issue where the train can enter the loop either way, but fail to exit cleanly.
If it's a loop in the sense that the diverging leg of a turnout comes back to the straight leg, it pretty much has to have the whole train fit inside the reverse section, or the engine would hit the tail end. However - what brand of turnout is used here?
When the train halts existing the loop - does the breaker in the main system trip? This could indicate something like the issue of one feeder crossed, or a bad gap, or simply inadequate feeders in the reverse section.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
jjdamnitAre you running DC or DCC?
The OP's original thread
He is running a MRC Prodigy Advanced.
gregcwhich model AR and how it is wired Ad
Currently MRC only lists one Reversing Unit and there are only 4 wires to deal with.
As I understand it, MRC has checked his Prodigy, looked at his track plan and 3 AR's don't work in one direction on the reversing loop.
Seems unlikely that MRC doesn't know how to make an AR compatible with the Prodigy. The unidrectional operation of the AR ought to be telling us something, but I don't know what. Maybe Stix nailed it.
Henry
COB Potomac & Northern
Shenandoah Valley
wjstixSimilarly, it could be one insulated rail joiner has gone bad, or a rail gap has somehow closed together over time, so one rail is no longer insulated.
wouldn't there be a short across the closed gap when the section matches the polarity at the other gap?
wjstixI had a similar problem at one time, trains went thru one direction OK but not the other.
CPbuffThe loco enters the loop over the Auto reverser(Gap A) and everything is fine, it proceeds around the loop but when the loco goes over the gap (Gap B) to leave , it stops... If I enter the loop the opposite direction it enters over the gap (Gap B) and proceeds around the loop over the AR leaving the loop(Gap A) theres no problem.
If I enter the loop the opposite direction it enters over the gap (Gap B) and proceeds around the loop over the AR leaving the loop(Gap A) theres no problem.
so the problem is only leaving the loop at gap B?
is there a short, either from the booster or the AR?
how far apart are the gaps at both ends from the AR connection to the mainline?
Agree with Stix, given that you have tried multiple AR's, possibility of other causes increases.
Hello All,
I don't know if this has been asked/answered...
Are you running DC or DCC?
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
I had a similar problem at one time, trains went thru one direction OK but not the other. Turns out one of the feeders for one rail in the reverse loop got connected to the 'regular' wiring for the rest of the layout in error. Going one way, the polarity matched, the other, it didn't. I'd suggest going over or even re-doing all your wiring relating to the reverse loop to be sure something like that isn't happening.
Similarly, it could be one insulated rail joiner has gone bad, or a rail gap has somehow closed together over time, so one rail is no longer insulated. It would have a similar result, trains would only work one direction.
In either case, it's possible to have a trickle of power that's not enough to trip the short circuit detector, but is enough to mess up the reverser.
richg1998It might help if you post the diagram here.
which model AR and how it is wired
Does this happen with multiple locos? When you approach gap B the rails are out of phase and the reverser corrects that problem. If you run a loco over B and bring the rails in phase, and then place another loco in the loop and run it through B (with the rails already in phase) does the loco still stop? Trying to see if other factors are in play.
It might help if you post the diagram here. You look fairly new so you will need a photo hosting site for the photo if not aware.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Well its been a year since I posted a problem with the MRC Auto reverser on a balloon track. Since then I have changed the layout to leave only one reverse loop or balloon track and a slight problem still exists... The loco enters the loop over the Auto reverser(Gap A) and everything is fine, it proceeds around the loop but when the loco goes over the gap (Gap B) to leave , it stops... If I enter the loop the opposite direction it enters over the gap (Gap B) and proceeds around the loop over the AR leaving the loop(Gap A) theres no problem... I have tried 3 AR's , 2 of which are brand new! I have sent the control unit back to the manufacturer for testing as we thought there was a problem with voltage supplied to the track and they say all is good! I also send a diagram of the layout to the manufacterer and they see no problems. Should I look at stay alive capacitors? Or just be happy with a loop around with no capability of reversing directions?