I'm having problems with both of my Athearn Challengers, UP 3983 and Rio Grande 3804 causing my DCC controler to go to short mode, it displays SVDA. The DDC is a MRC Prodigy Express. The 2 challengers are the older ones that came with the small hand remote when operating on DC.
I'm not super experienced with DCC, I was into model railroading as a child and teenager but this was 30-40 years ago. I'm now getting back into it and I bought a completed layout recently.
I've seen some turnouts for sale that are listed as "DCC Compatible". Is that what I need? If so I'm guessing the turnouts on this layout are not?
I have other engines that work perfetly fine, a Broadway Limited 2-8-0, Broadway Limited SW7, and an Athearn Genisis GP7, they never cause this problem so it is something specific to the two Challenger Units.
Any suggestions you would have would be appreciated as my 8 yeaer old really wants to run the Challengers!
I presume "over turnouts" means through the diverging (curved) portion of the turnout? Also, what size turnouts are these issues happening on?
Given those are really large locomotives, I'm going to guess that the front pilot wheels are shorting to the chassis. You can verify this by removing one of the them and running that locomotive through the turnout.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Thanks for the reply.
This happens when going straight through the turnout or when taking the diverging route.
I don't know the size of the turnouts, how do I measure that?
Taking the pilot of sounds easy enough, next chance I get I will give that a try!
I had a problem like this with Peco turnouts. The frog itself on these is plastic, but the approaching rails almost touch at the frog. So, engines with wide wheels would sometimes bridge the gap between the metal rails and cause a short.
Believe it or not, the solution was to put a dab of nail polish on the frog gap, insulating the the rails by effectively making the plastic section a bit larger.
I'd recommend either black or clear polish, to make the fiix less noticeable.
It takes an iron man to play with a toy iron horse.
I forgot to mention that I've tried this already with little to no improvement, but perhapds I didn't do a good enough job? I could always try again.
Doggone it, Mr. B. beat me to it.
Since the other locos have no problem traversing the turnouts, its gotta be the Challengers. The wider driver wheels touch converging rails of opposite polarity on the turnout causing a short. Clear nail polish is your friend.
Rich
Alton Junction
Check your wheel gauging. DCC systems react to the slightest indication of a short circuit, and out of gauge wheels are one cause.
Basically, almost all turnouts are compatible with DCC. Some may require a few tweaks to eliminate issues.
DCC Friendly Turnouts
If the wheels are out of gauge can that be corrected?
IbanezGuiness If the wheels are out of gauge can that be corrected?
It can be done. It may be a simple thing, but with a steam locomotive's mechanism, it is best to get help from someone who knows what to do and has the tools. It is too easy to make a mistake and introduce a new problem, especially with respect to the quartering.
Also check the turnouts with the gauge to ensure everything there is correct.
IbanezGuinessIf the wheels are out of gauge can that be corrected?
Probably better for you to check the gauge first rather than get your drawers in a bunch unnecessarily.
I tried running it without the front pilot and that made no difference. I've ordered a track gauge and I'll do some checking once I get it.
I've heard the MRC decoders in these aren't that good. Is it possible the decoder is causing this problem?
I'm still thinking that it is the driver wheels touching converging rails of opposite polarity.
Track gauge arrived and I had a few mintues to check each locomotive, all of the wheels fit within the gauge, a few were tight but this was because they were just a bit on the narrow side, not too wide. However I had no problems getting the flange of each wheel pair into the gauge.
One thing however that I didn't think about earlier is that the rear drivers are missing the traction tires, they were dried out and falling apart so I just removed them. The gap left without the traction tires is wide enough that a rail will fit inside it. I wonder if that could be the cause of my problems??? I'd like to replace these but it does not look trivial and I don't have the easiest time working on small stuff like this.
I haven't had time yet to check the gauge of all of the turnouts yet.
IbanezGuiness Track gauge arrived and I had a few mintues to check each locomotive, all of the wheels fit within the gauge, a few were tight but this was because they were just a bit on the narrow side, not too wide. However I had no problems getting the flange of each wheel pair into the gauge. One thing however that I didn't think about earlier is that the rear drivers are missing the traction tires, they were dried out and falling apart so I just removed them. The gap left without the traction tires is wide enough that a rail will fit inside it. I wonder if that could be the cause of my problems??? I'd like to replace these but it does not look trivial and I don't have the easiest time working on small stuff like this. I haven't had time yet to check the gauge of all of the turnouts yet.
CharlieM After replacing the original MRC decoder with a Tsunami 2 it’s a reliable and well performing engine. I would look closely at your Challengers for problems. Charlie - Northern Colorado
So who made the turnouts and what model are they? The fix for Pecos is easy and obvious. If they're not Pecos, we need to look further.
IbanezGuinessOne thing however that I didn't think about earlier is that the rear drivers are missing the traction tires, they were dried out and falling apart so I just removed them. The gap left without the traction tires is wide enough that a rail will fit inside it. I wonder if that could be the cause of my problems???
Anyone have an opinion?
IbanezGuinessI don't know the size of the turnouts, how do I measure that?
Easiest way is, when you bought the turnouts, the package would say something like "No. 4 turnout" or "No. 6 turnout". The higher the number, the more gradual the angle of the turnout. If you don't still have the packaging, it may have information on the bottom of the turnout. If nothing else, might have the manufacturer name and a part number you could then use to look up the turnout online.
I suppose it's possible the missing traction tire could cause a problem, though it seems unlikely to me. If you can get another one from Athearn, undoing one siderod connection to slip it on isn't all that hard. Otherwise you could try filling it in with Bullfrog Snot and see if that works.
wjstixI suppose it's possible the missing traction tire could cause a problem,
It is unclear to me if he means one traction tire or mutiple. He says "they" which to me means more than one.
Is there one missing from each side? And if missing from both sides are the sides still insulated from each other?
wjstix IbanezGuiness I don't know the size of the turnouts, how do I measure that? Easiest way is, when you bought the turnouts, the package would say something like "No. 4 turnout" or "No. 6 turnout". The higher the number, the more gradual the angle of the turnout. If you don't still have the packaging, it may have information on the bottom of the turnout. If nothing else, might have the manufacturer name and a part number you could then use to look up the turnout online. I suppose it's possible the missing traction tire could cause a problem, though it seems unlikely to me. If you can get another one from Athearn, undoing one siderod connection to slip it on isn't all that hard. Otherwise you could try filling it in with Bullfrog Snot and see if that works.
IbanezGuiness I don't know the size of the turnouts, how do I measure that?
Simon
I'd be interested in knowing when exactly the short happens - like is it when the first driver hits the frog, or when the engine is farther along, etc.? Plus we don't know what kind of track the OP is using, so don't know if it's a power routing turnout or deadfrog or what.
https://live.staticflickr.com/65535/53877301589_70e60c677b_m.jpg
Ibanez, I had exactly the same problem with a handlayed Turnout. I cut the rail gaps in the closure and wing rails too close to the frog which led to shorting. I cut additional sets of gaps further from the frog to allow a bit more distance between the closures and wings. If it turns out to be true that the wheels (tires) are wider (NMRA Standards?), you might want to try the method I describe below.
The fix:
1) Apply 5 or 6 drops of liquid (not gel) ACC to the area of the new gaps. Let set for an hour or so.
2) Using a 32-tooth razor saw, cut the gaps. Now, and this is important. It should take 20 or so slow saw strokes to make a complete gap. If you use fewer strokes, each stroke will require more force that might move the short piece of rail next to the frog. It would a good idea to make 10 or so practice cuts on a spare picece of track until you get a feel for cutting rail. A trick to start the cut is to turn the saw backwards and using the teeth close to the handle, draw the saw lightly backwards across the rail top a few times to score (scratch) the top of the rail. Once scored, turn the saw and starting slowly, cut the gap. If the teeth catch, it means that your are applying too much pressure between the saw and rail - back off slightly. A cool head is the main thing!
Actually, you only need to cut one rail.
Note in the photo that I use .010 styrene to fill the gap. Insert the plastic, add a drop or two of the ACC in the gap, let dry and trim the plastic to the contour of the rail.
Final point. If you completely loose your mind and the small piece of rail moves, simply move it back with needle nose plyers and apply a bit more ACC.
I bought the layout used already built, I don't know who made the turnouts. They are balasted so getting one out to see a brand on the bottom wouldn't be easy.
maxman There are 2 traction tires on the rear wheels of the rear engine. wjstix I suppose it's possible the missing traction tire could cause a problem, It is unclear to me if he means one traction tire or mutiple. He says "they" which to me means more than one. Is there one missing from each side? And if missing from both sides are the sides still insulated from each other?
There are 2 traction tires on the rear wheels of the rear engine.
wjstix I suppose it's possible the missing traction tire could cause a problem,
snjroy I honestly haven't been able to figure that out yet because I haven't been able to see a visible arc, just the short message on the DCC controller. I have had very little free time lately, when my son and I do run some trains we just haven't been running the challengers. I do want to get this sorted out at some point soon thought. Thanks everyone for the replies. wjstix IbanezGuiness I don't know the size of the turnouts, how do I measure that? Easiest way is, when you bought the turnouts, the package would say something like "No. 4 turnout" or "No. 6 turnout". The higher the number, the more gradual the angle of the turnout. If you don't still have the packaging, it may have information on the bottom of the turnout. If nothing else, might have the manufacturer name and a part number you could then use to look up the turnout online. I suppose it's possible the missing traction tire could cause a problem, though it seems unlikely to me. If you can get another one from Athearn, undoing one siderod connection to slip it on isn't all that hard. Otherwise you could try filling it in with Bullfrog Snot and see if that works. I have succesfully replaced one on a Mantua with Bullfrog Snot. A missing tire will cause operational issues and should be fixed. Simon
I honestly haven't been able to figure that out yet because I haven't been able to see a visible arc, just the short message on the DCC controller.
I have had very little free time lately, when my son and I do run some trains we just haven't been running the challengers. I do want to get this sorted out at some point soon thought. Thanks everyone for the replies.
I have succesfully replaced one on a Mantua with Bullfrog Snot. A missing tire will cause operational issues and should be fixed.
When the short happens, the engine should stop and the DCC system give some type of beep as an alarm. I would suggest running the Challenger as slowly as possible and see where exactly it is in the turnout when the short happens.
If it stops at say one of the drivers, try moving the driver side-to-side a little and see if that stops the short. Because these engines are so big, but still can go around sharp (mine will do a 22"R curve), the drivers have a lot of lateral side-to-side play and it's possible that's causing something to touch something that is doing the short.
Can the OP take a picture and post a photo of the turnout so we can possibly identify it? The instructions are at the top of the General Discussions forum.
Yes, it's a bit of a chore to set up the first one, but it gets easier after that.
So I'm pretty confident I've figured out what is going on. I spent some time with a really bright light watching the loco go through the turnouts and I found a slow enough speed the loco would stop when the short happened.
Because the traction tires are missing on the very rear wheels of the second engine the rail is going up into the groove where the traction tire would be. This is causing the wheel to run over the rail lowering it which in turn raises the front wheel of the rear engine. This is resulting in the flanges not always centering through the frogs and allowing the wheel to get off track and causing the shorts.
So it looks like I just need to replace these traction tires. I will probaby start a new thread with help on where to get them and how to do it.