As a novice trying to create a layout with my son, I have hit a roadblock. I have built the Atlas Up & Over Dogbone and know based on reading where the reverse section lies, and where to place the 5 insulated gaps. Using Digitrax DCC controller, the engine is extremely inconsistent when entering and exiting the reverse section. 95% of the time now it just stops completely upon entering loop, without the properly wired AR1 working. Occasionally, however it will work, but woefully inconsistent. I understand this could be many things, but I have checked the diagrams and wiring seems OK - used 14g bus line, and a few 20g feeders. The reverse section is not that long (4 ft or so), and the train is not overlapping or too long for the reverse section. Do the experts think I may need more feeders throughout the track? The "quarter" test is fine everywhere though. Does the "quarter" test indicate my track has enough electric current, or am I being too naive? Frustrating because a few weeks ago, everything worked, just hesitated throught the reverse section....now just stops completely. Track cleaning did nothing. Need help or a house call.
Steve,
The AR-1 has an adjustable trip current. Have you tried adjusting it yet?
Since it did work previously, it's possible it's something else, but this will make a difference in how the reverser senses the need to change.
Mike Lehman
Urbana, IL
Yes. Thanks, I forgot to include that I've been playing with the trip settings and so far, no consistent success.
I'm hesitant to redo wiring given that it HAS worked, but i also understand that the answer is probably in an electrical problem that this novice can't figure out.
The quarter test is a good sign, but if you wired it per the Atlas diagram you may need more feeders just the same. Rail joiners are a notoriously bad connection, so with sectional track where there are many, you either need more feeders, the joints soldered, or jumpers soldered to the rail bypassing the rail joint.
The AR1 is adjustable, if set too high then it will be unreliable and not always trip before the command station. Another thing to do, if you are using a Digitrac DCC system, is extend the delay before the main circuit breaker trips. These are listed in the Configuring the Command Station section near the back of the manual. In fact if you preciouly had this set and maybe reset the system, it will have reverted to the factory defaults.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Mike - thanks for your suggestion. Yes, I did try the adjustable trip current and no success. Engine still stops as it enters the reversal section. I can only assume it's an electical problem, however, since the train was working with little problem previously, I'm hesitant to start re-wiring....keep in mind, I'm quite a novice.
Can adding more feeders help the consistency of the current? I have some, but could always add more. It's not a huge layout. Any other way to test the problem, or should I just assume electrical and start reinforcing the wiring of the track?
Thanks to all -
Steve
rrinker In fact if you preciouly had this set and maybe reset the system, it will have reverted to the factory defaults.
Randy,
Good point. That could account for something changing to cause this when it was previously working.
As an owner of five AR-1 units, I got about halfway through the OP's post and came to the same conclusion as Randy and Mike. The TTC screw needs to be adjusted. There is a plastic screw on the AR-1 with a slot on it so that it can be turned and adjusted with a screw driver blade. That screw is called Tunable Trip Current (TTC).
Rich
Alton Junction
1. Well, thanks everyone for your help. As you might have predicted, I added some additional feeders to the main track, and reverse loop....then adjusted then trip switch...and MUCH better!
2. Just for my own education, is 18g-20g wire about the largest that can fit in the AR1 connections? Does that matter for performance?...the rest of my main track layout is 22g feeders to 14g buss wiring.
If you want to feed it with larger wire, just solder a short piece of the 18-20g onto the end of the connecting wire. The short length will not interfere with the gained capacity.
I suspect they wanted to limit the load going through the AR-1 for some reason. Unless you add a whole bunch of draw in the reversing district by adding locos, lights ,etc, that won't be problem with doing this.
Short pieces of smaller wire won;t hurt anything. The PM42 can't handle #14 or #12 wire, so I just used short pieces of smaller wire that does fit and ran them to a terminal strip, the #14 hooks on there. It's pretty much the same with feeders, you can;t really solder #14 right to HO rail (well, you CAN, it would just look horrible and maybe not have enough clearence for the wheels) but the short length of the smaller feeders is insignificant and you don't get a huge voltage drop like you would if you ran that thinner wire all the way back to the booster.
rrinker ...."The PM42 can't handle #14 or #12 wire".... --Randy
...."The PM42 can't handle #14 or #12 wire"....
This is why I spent the $36 for a breakout board for the PM42 that has #14 capacity terminals for each of the (4) outputs when I configured my layout Randy. Quick and simple (just plug the PM42 into it and you're ready to go).
The break out boards from www.Acculites.com are what I use and am happy with them.