Hi Everyone!
I've posted occassionially in the past and everyone here has always been helpful. Hopefully, you can help again.
I recenlty converted my railroad to DCC as well as changing my track from brass to nickel sivler. All of my track is Atlas. I've been testing the electrical integrity of the layout and everthing is fine with the exception of one thing. I have a Broadway Limited EMD SW7. When it goes over an Atlas 19 degree crossing, the engine is momentarily powered. It then loses power and stops. I don't have the same issue with my other engines which are Athearns GP39-2 amd SD70M2.
Could this issue be solved by just added track feeders around the crossing or is something else going on? Any help and suggestions would be greatly appreciated.
Thanks,
Mark
A couple of possibilities here.
One, are the front and rear trucks both powered? To check, place the locomotive on a straight section of track and run it at full power. While it is running, lift up the front end of the locomotive and observe whether the wheels on the rear truck are spinning. If they are, you have power to the rear truck. Now, set the front of the locomotive back on the track, lift up the rear end of the locomotive, and observe whether the wheels on the front truck are spinning. If they are, you have power to the front truck.
Two, use an ohm meter to test for continuity across all four rails. Each rail is divided into three segments, and each segment should be powered with the power on. The frogs are unpowered, but there are jumpers embedded in the crossing to connect the rail segements. Turn the power off and put one probe from the ohm meteron the first rail segment and the other probe on the adjacent rail segment. If there is continuity, repeat the test from the second rail segment to the third rail segment. If there is continuity, then there is no problem with any of the rail segments.
Three, turn on power and run the locomotive very slowly over the crossing. Note where it stops. It may be on one of the unpowered frogs. A "diamond" crossing has four frogs, two acute frogs and two obtuse frogs. Run the loco very slowly in each direction on each pair of rails.
Rich
Alton Junction
mark4253I have a Broadway Limited EMD SW7. When it goes over an Atlas 19 degree crossing, the engine is momentarily powered. It then loses power and stops. I don't have the same issue with my other engines which are Athearns GP39-2 amd SD70M2.
The Atlas 19 degree crossing has four big insulated plastic frogs. These play games with any short wheelbase locomotive with less-than-perfect power pick up.
Your Athearn locomotives probably have excellent power pickup from all wheels. They will not have any problem at all with this piece of trackwork.
My limited experience with BLI has indicated that power pickup is not anywhere near as bullet-proof as Athearn and Kato. Add to that how short the SW-7 is, and this piece of trackwork will probably not play well with that locomotive.
-Kevin
Living the dream.
If you can fit one inside, install a keep-alive circuit. It will keep your loco running over the plastic frogs.
Hornblower
I had an Atlas 30 degree crossing. I had one locomotive that always shorted out on it. I determined that the fauilt was actually in the crossing itself. I replaced it with a Walthers crossing and solved the problem.
It takes an iron man to play with a toy iron horse.
The loco you mention, as a previous responder has suggested, is too short a pickup wheelbase to get over that longer crossing. A keepalive would help, but getting it into the mix will be tough under that shell. Maybe in the cab...?
I have not had great success with any complicated crossings and turnouts available commercially. They all have some minor defects which impede happy running. Maybe not will every locomotive, but with enough of them that I know it isn't the locomotive, it's the crossing. I have had to file them with needle files in the flange-path so that the tires stay in reasonably good and consistent contact with the rails as the first truck crosses, and then as the second crosses. Those appliances are not what one would call 'precision rails'.
It could be that, if you were to trace the crossing for length and angle, a person who makes customized trackwork, using hand-laid techniques, would make a far superior crossing for you. It might cost near $40...plus, maybe, but it would be good for many layouts and your little switcher would have little trouble with it.
BTW, does your loco by any chance have a traction tire or two? My Walthers SW-8 had them. I got mine switched out with a proper axle as soon as Walthers shipped me one.
Railroad of LION uses 48 wheel pick-up.
I did not bother to wire an entire double cross-over.
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
BroadwayLionRailroad of LION uses 48 wheel pick-up. I did not bother to wire an entire double cross-over.
My pair of Athearn PAs are wired together for 24 wheel pick-up. They never ever stall.
I have three Athearn locomotives (F-45s I think) that will push/pull my track polishing train. They will have 36 wheel pick-up all wired together.
I have a pair of Powered Athern P7s or something, A units, I also have a B unit but not powered. but it has the metal trucks with power pick-up.
I have to tie locomotives like that because I use track gaps, and they all have to keep power until they are all across the gap. If this is end of the line there is a rectifier so that when the power reversed the unit will be able to leave.
Thanks for your replies and sorry for delayed response. Since I'm still kind of new to DCC, several of you mentioned "a keep-alive circuit." What does it do, how do I install it, which suppier can I get it from and how much does it cost?
Selector asked: "BTW, does your loco by any chance have a traction tire or two? My Walthers SW-8 had them. I got mine switched out with a proper axle as soon as Walthers shipped me one." Sorry, since I'm new to this, not sure what you mean about the "proper axle."
Hello Mark,
A Keep Alive is basically a capacitor that will store energy and allow your locomotive to cross over frogs that are not powered or even some dirty track. TCS I think was the first one to come up with the component.
https://tcsdcc.com/keepalive
The "proper axle" is just one that does not have a traction tire. A traction tire is like a small rubber band that goes around a wheel to improve the pulling power of a locomotive. But you sacrifice electrical pick-up. Many modelers feel they get enough pulling power without the traction tire, and would rather have the extra electrical pick-up that the non-traction tire axle provides.
I hope this helps.
Scott
Yes, this does help. Thanks for the information Scott. I'll check out the keep alive. I just went to the website you provided and I saw it gets intalled in the Locomotive. I'll have to see if I have room for it. My loco does not have a traction tire which means I should have good electrical pickup, just not over this particualr crossing.