I'm having problems with a set of four Athearn Ready-to-Run SD40T's (HO) equipped with Soundtraxx AT-1000 decoders. When consisted, they randomly momentary lose power and restart, accompanied by the usual flashing lamps and engine start sounds. They've been speed matched, and generally run OK separated, but when in consist, they lose power at various locations. I'm wondering if it's possible that the Kadee whisker couplers cause this. These locos came with plastic couplers, which were removed as I've had these break knuckles on the 80-100 car trains.
I ran the same long train with four MTH SD70's, and it runs flawlessly. All the usual Athearn issues have been addressed: plastic wire terminal clips replaced with soldered connections; NWSL wheels; truck pickup wires soldered to the metal frames; etc. Nice looking and soundng locos, but out of eight of them I can't get any four to run well together.
Any ideas?
The Kadee whisker couplers could well be your problem -- the frames are hot on Athearn RTR locomotives, which are actually just old blue box models pre-assembed.
Try changing to a Kadee or other brand of plastic coupler on one end of each unit in the consist so you don't have two metal couplers touching each other, and see if that doesn't solve the problem.
Thanks! I didn't know the frames were "hot". I'll give this a try.
Victor,
More than likely, that is your problem. Kadee #28 is a Plastic shank coupler.
http://www.kadee.com/htmbord/coupler.htm
Frank
BTW: I should include...You can use the so-called dreaded copper flat spring with that coupler. I use it on my BB SD40-2's, DC only.
To verify it before you swap couplers, run them all facing the same way - all short hood front or all long hood front. That makes the frames be connected to the same rail on each loco so there would be no short. If they run fine like that, shorting through the coupler and hot frame is definitely the problem.
But it is anyway, 100% guaranteed. But if you wanted to test it out for sanity's sake....
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Well that's a bummer if it's the coupler.
Kadee makes a whole variety of couplers including the whiskers but they are all metal except for one line of plastic couplers. And, the plastic couplers are not whiskers, just standard couplers.
Rich
Alton Junction
I don't think the couplers are the issue, unless they built the RTR SD40T-2s different from the SD40-2s I have.
I have an Genesis F45 with a soundtraxx (pre-tsunami atlas board replacement), a Genesis Gp15-1 with a Tsunami, and a P2K GP9 with a Tsunami and they do the same thing regardless of the grouping of engines with them. I haven't tried it solo. I think it's an issue with the soundtraxx locos.
Vincent
Wants: 1. high-quality, sound equipped, SD40-2s, C636s, C30-7s, and F-units in BN. As for ones that don't cost an arm and a leg, that's out of the question....
2. An end to the limited-production and other crap that makes models harder to get and more expensive.
Athearn Ready to Run and Genesis are basically two very different product lines. As noted, RTR are based on the old "blue box" Athearn engines, which had trouble just as the OP described.
I think the problem is the keep alive cap. I have 2 of the AT1000 decoders that stalled crossing my reverse loop. I removed the factory one and installed a larger size cap. Problem went away. If space is small, you can add a second small cap IN SERIES with the factory one. Joe
Caps in series reduce the total value. Caps in parallel add the total value.
Common knowledge.
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.
.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
In parralell is correct. Common knowledge works when your brain does. Ah senior moments are great !!!!!! Joe
I hope the author of this post solves this problem and posts the "answer". I too suspect that the decoder is the issue here...if you're running in " consist " mode you must have set up the engines to go in the same "direction" for a given throttle "setting" and I can't see KD coupler shorting being a problem here...even with "hot" frames. I have a couple of decoders that see every noise spike as an excuse to reset (i.e. stop and go). My solution has been to "store" the decoder for emergencies but I would now try the "stay alive" capacitor trick to see if that would save the decoder. Please post your results....I think a lot of modelers would benefit from the results.
Why would you not think metal couplers on a hot metal frame would not be an issue? If you set both locos so they face the same way, ie both with the short hood facing east, then there is no problem. But turn one around so one faces east and the other faces west, now you have the frame (and coupler) connected to the north rail on one loco, and the south rail on the other loco. This problem is as old as Kadee couplers and Athearn Blue Box locos. The same problem exists running them on DC. On DC, if you had enough power, they would run, but need way more throttle than expected, and the coupler area would get hot. With DCC, since the electronic breakers are much quicker acting, it will shut things down more often than not. If it were just one unit trying to go the opposite direction because they weren't consisted correctly, they wouldn;t run in the same direction when uncoupled, and even coupled, they would either just sit there and play tug of war with each other, or if there were 2 facing one direction vs 1 facing the other way, slowly drag the one around the layout with its wheels spinning.
It always was a tricky short to diagnose, because not only is the coupler not tightly mounted to the frame (hopefully - they work MUCH better if they can swivel around curves) AND because the blackening makes them less than ideal conductors, there often isn't a continuous short, just when the couplers are pulled or pushed tight. Like setting your multimeter on the highest ohms range and squeezing the probes. The hrder you can squeeze, the lower the resistence reading you will get (don't press on the pointed end of the probes, you can drive them right into your finger that way).
In the described engines the OP has, aren't the couplers mounted in a plastic box over an internal plastic post ? How would the couplers come in contact with the chassis ?
Mark.
If it's RTR I belive they have couplers in a plastic box screwed to the frame. I still say it's a keep alive cap problem as it is intermitent. If the couplers when the locos were put on the track and caused a short, the command station should shut down until the short was fixed. On my Digitrax, it makes beeps to alert you of a short. Joe
If this has always been a problem with these engines, I'd be willing to bet it's the metal slots that the bronxe axle journals ride in have paint in them. Ever since Athearn started to paint the metal plates on the truck assembly, I've found paint overspray in those slots to be a major contributor to intermittent contact.
Scrape the bottom and sides with an x-acto blade and see if that makes any difference.
ba&prr I think the problem is the keep alive cap. I have 2 of the AT1000 decoders that stalled crossing my reverse loop. I removed the factory one and installed a larger size cap. Problem went away. If space is small, you can add a second small cap IN SERIES with the factory one. Joe
Are you referring to the cap that comes with the AT-1000 board ? If so, that cap is strictly a stay alive cap JUST for the sound. It has no effect on motor control what-so-ever.
Maybe, but I an AT in a diesel that had a similar problem. I added a second keep alive cap and the problem went away. Joe
The CurrentKeeper (P.N. 810140) maintains power to the decoder for up to 10 seconds during electrical interruptions for hiccup-free operation of sound, lights and motor. It measures 40mm x 6mm x 11mm and has an MSRP of $24.95.
From Soundtraxx you tube demo. Joe
ba&prr Maybe, but I an AT in a diesel that had a similar problem. I added a second keep alive cap and the problem went away. Joe
Purely coincidence then. Here's the layout and an explanation of the circuitry ....
http://wayback.archive.org/web/20120729061658/http:/www.members.optusnet.com.au/mainnorth/alive.htm
ba&prr The CurrentKeeper (P.N. 810140) maintains power to the decoder for up to 10 seconds during electrical interruptions for hiccup-free operation of sound, lights and motor. It measures 40mm x 6mm x 11mm and has an MSRP of $24.95. From Soundtraxx you tube demo. Joe
The Current Keeper does not wire into the same place as the capacitor that comes on the board. The current keeper attaches to the same black wire, but not the red, but rather the blue so it will feed the motor circuit as well.
If the coupler mounts tot he BODY - no problem. If it mounts to the frame - problem. Sure, it's in a pkastic box. But it's a METAL coupler with a METAL screw up the middle. That's why it's so intermittant - at rest, the couple likely does not touch the metal screw, at least not with enough force to lower the resistence enough to make much of a short.
Kadee didn't come up with couplers with a plastic shank because they wanted to make plastic couplers or they were trying to save money over all-metal couplers.
If a plastic shank coupler is being used, and/or it is body-mounted and not screwed in tot he frame in any way, then indeed the problem lies elsewhere. But if the locos run fine singly, then there is no issue with the power pickups or the wheels being dirty or any of that. All that really happens in consisting, when you get down to it, is that all locos in the consist get the same DCC command, so there should be no difference in operation. Easy to prove out the couplers, either run them all the same direction, or consist them but not have them coupled up, keep them a foot or so apart. If they work fine that way, it's not a decoder or consisting issue.
I have 2 Athearn RTR RS3's with Kadee metal couplers I covsist with one facing forward and one reverse. I have Tsu's installed with a larger cap in each. No stall or intermitent problems with them. There is a plastic boss that the hole in the coupler shank goes over. The coupler box is plastic as well. With the boss, the coupler is isolated from the frame and screw. It could also be a bad solder joint on the track pick up yabs or the motor tabs as well. Joe
The RS-3's are pretty much hit or miss. I had to get 2 before I had one that actually ran - but this was just singly. The first one had almost no pickup from the one truck, despite adding hard wiring from the truck frames right to the board (no longer relying on the bolster and frame, or the one wire sandwiched between the frame and the board). I've come to the conclusion that the problem is between the brass bushings and the metal truck frame - the plastic now used to hide the shiny metal that used to be visible in the old Blue Box locos seems to be preventing the bushings from properly contacting the metal. I guess soldering pickup wires to each individual bushing would solve this. The second unit I got thankfully very cheap (about $20! - wonder why the value plummetted so fast...) and it ran fine, so I just swapped shells with the one I wanted. I have a whole stack of undec Atlas/Kato RS-3's, think I'll stick with those, they are much better runners.
as BA&prr explained there is a plastic ring in the coupler box that isolates the couple from the mounting screw (in the RTR versions). This is true of most of Kadee's couple boxes in addition to the RTR boxes used by Athearn. if it is a older blue box model then there can be hot frame issues. The blue box models used a plastic clip to hold the coupler in place and the couplers could directly contact the frame.
The other option rather than using a plastic couple (which I do not allow on my layout, too many break) is to use a plastic screw and Kadee couple box. This will prevent pretty much all hot frame issues from creating shorts with other locomotives.
The majority of my fleet is Athearn (super detailed RTR and blue box) locomotives and I have zero issues. THe only time i have intermittent issues with my locos is dirty track/dirty wheels.
I have been in the construction phase of the new layout so the track is filty at the moment. The sound decoders really don't like that at all.
Colorado Front Range Railroad: http://www.coloradofrontrangerr.com/
I have seen an occasion where the short was through the metal glad hands touching each other and the frames at the same time.This was on a couple of metal Hobbytown units.The only solution I came up with is a unit in between with out a hot frame issue. I run DC so it was an occasional minor issue
Ron High
What if you trimmed the glad hands back a bit? Joe
It appears that some do not know that Kadee makes a plastic shank coupler, the knuckle is metal, the shank is plastic. The whole coupler is not plastic. #28, is the same as #5 and #148.
I didn't know that either. I wonder how strong they are? Joe