A couple years ago I purchased an Atlas RS-1 on ebay. It's an old fashioned DC loco and nothing DCC friendly about it. I got the most basic Digitrax decoder because I saw no chance of fitting both a decoder and speaker in the narrow shell for sound. I had to splice into the power wires and solder the 4 basic decoder wires. After completing that, I had a heck of a time fitting everything back into the shell and clamp it back into place. Several times I broke one of the soldering joints and had to resolder it. Finally I squeezed everything in and was able to clamp the shell down so it clicked into place.
I assigned the decoder address and started a test run. It ran fine forward but when I reversed it, it derailed at the first turnout it passed over. I could easily see why. By stuffing the decoder and wiring back into the one small space inside the shell that would accomodate them, the assembly was pushing down on the front of one of the power trucks causing the rear wheels to raise up off the track. I took the shell back off and tried to rework everything and discovered I could no longer power the motor. The light was coming on so it was getting power but the motor was not moving. I suspect what might have happened is that in stuffing everything into that small space, the tape I was using to insulate the soldered joints might have come off and caused a short which damaged the decoder.
I really like this engine and want to make it part of my roster. I'm hoping there is a smaller sized decoder that would more readily fit in the narrow shell. Just a basic decoder to control the motor and work the headlight is all I need. Can anyone recommend a good HO decoder that would work in this loco.
I am not a decoder expert but I hardwired a TCS MC2 decoder in a Bachmann GE 44 Tonner recently and it is quite a small decoder with good slow speed control.
I don't know for sure if it will fit in your RS1 but you can go on TCS web site and compare MC2 dimensions with your decoder.
Guy
Modeling CNR in the 50's
I have two Atlas RS-1 locomotives, and the NCE DA-SR decoder fits quite nicely.
If you are willing to forego sound, the DA-SR will work just fine.
Rich
Alton Junction
If this is HO, the Kato-made ones, it IS DCC ready. You just repalce the palstic 'board' with an Atlas /Kato board format decoder such as the TCS A4x. Plugs and sockets do not "dcc ready" make - the P2K S1 has an 8 pin socket yet is NOT DCC ready (despite the claim on the box!) since the motor is not properly isolate. Motor isolation is what makes DCC Ready.
The only complicated part about the Atlas/Kato Alcos is mechanical - cutting down the light bars so you can put in two lights or LEDs and have independent lights front and rear instead of one bulb in the middle.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy touched on what your problem is .... the two light bars. They just don't allow any room for anything else to fit into the shell. The simplest fix is to cut the light bars shorter - about a quarter inch inside of the ends, then shrink-tube an LED onto the end of the remaining stub.
The TCS A4X decoder is a drop-in replacement for the old plastic board, the the decoder doesn't require extra resistors to be added for the LEDs - they can be attached directly to the decoder as it already has resistors on it for the LEDs.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Mark R. Randy touched on what your problem is .... the two light bars. They just don't allow any room for anything else to fit into the shell. The simplest fix is to cut the light bars shorter - about a quarter inch inside of the ends, then shrink-tube an LED onto the end of the remaining stub. The TCS A4X decoder is a drop-in replacement for the old plastic board, the the decoder doesn't require extra resistors to be added for the LEDs - they can be attached directly to the decoder as it already has resistors on it for the LEDs. Mark.
There is no old plastic board to replace. I don't know how old this loco is but it is wired the way my Atlas locos from the 1980s were. Wires run directly from the powered trucks to the motor. I had to splice a basic decoder into those wires and solder them. It definitely can't use a drop in decoder the way more modern DC locos do.
richhotrain I have two Atlas RS-1 locomotives, and the NCE DA-SR decoder fits quite nicely. If you are willing to forego sound, the DA-SR will work just fine. Rich
This sounds like the best bet. I'll look into it. As long as it has wires I can solder to the existing wiring of the loco, I'm guessing it will work.
It doesn't look like this ? ....
https://www.flickr.com/photos/frankzappai/16431918649/
I was able to get a Digitrax DH123D into my Atlas RS-1. The decoder is taped to the top of the motor, I think and I believe I used the light tunnels, as the body comes off without wires. I need to take it apart to remember how I did it, maybe I will do that today.
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
Interesting, I am only aware of maybe 3 versiosn of the RS-1, the original Kato one with the plastic board, the first Atlas motor ones with a regular circuit board, and the later Atlas ones that add an 8 pin socket. At least in HO. Was there an even earlier one, from when Roco made Atlas locos, which would just have wires?
rrinker Interesting, I am only aware of maybe 3 versiosn of the RS-1, the original Kato one with the plastic board, the first Atlas motor ones with a regular circuit board, and the later Atlas ones that add an 8 pin socket. At least in HO. Was there an even earlier one, from when Roco made Atlas locos, which would just have wires? --Randy
That's my thinking as well. The one I posted a picture of came out in the late 80's.
Yes, I have a large stash of that era RS-3, since I need lots of them. I've converted a bunch. So far motor only, but the next couple I am going to put sound in.
rrinker Yes, I have a large stash of that era RS-3, since I need lots of them. I've converted a bunch. So far motor only, but the next couple I am going to put sound in. --Randy
If you figure out where to put a speaker, let me know.
Mark R. It doesn't look like this ? .... https://www.flickr.com/photos/frankzappai/16431918649/ Mark.
That is exactly what it looked like. I tried to cram the Digitrax decoder behind the motor (to the right of it in this picture). I managed to squeeze it in and still get the shell back on but it was pushing down on the powered truck to the point where it forced the wheels closest to the motor raised up.
Maybe I should have tried it on top of the motor as NP2626 suggested. I'm going to see if that works if I haven't fried the decoder.
Does anyone know a method of testing to see if a decoder is still good other than to wire it to the loco and see if it still works. I tried clamping the lead wires to my programming track and seeing if I could set the address that way. It didn't accept it which is why I think I might have fried it.
As I mentioned in my original reply, the TCS A4X decoder is a direct replacement for that plastic board ....
That TCS A4X decoder has the same footprint as the NCE DA-SR decoder.
If you want sound, Loksound makes the same style board as well (Loksound Select Direct) and there's plenty of room to install a small speaker in the end over the truck at either (or both) end as the RS1 doesn't have the separate weights over the trucks like the RS3 does.
I have an article saved that shows how to do it in an RS3. Not really that difficult - kind of easy if you just completely give up one of the weights, or you can slice it down. That fits a bigger speaker than you could cram in the cab, plus you don;t see it.
As for the OP - those two long brass fingers on either side are clipped under tabs on that plastic. The pop off. Then the whole big piece of grey plastic comes off, leaving a space for either the various board decoders (add a third - the Digitrax DH165A0 (or the DH165K0 - for extra cost you can have them solder on littpe pieces of wire for the connectors on the truck wires to slide on to). So that's 3 options for motor decoders, or the Loksound Select Direct is a drop in board sound decoder. Or, with all that room, you can now hard wire a regular harnessed decoder, no need to cram anything. That grey plastic 'board' eats up a lot of space.
Here's a step by step for you ....
http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Atlas/RS1/RS1.htm
Mark R. As I mentioned in my original reply, the TCS A4X decoder is a direct replacement for that plastic board .... Mark.
I misunderstood what you meant by a plastic board. I thought you were referring to a circuit board. Many of the more recent DC locos I have converted had a small circuit board which could be swapped out with a decoder in its place.
I like that the decoder has terminals to be soldered to. The Digitrax decoder I tried to use had nothing but lose wires that need to be spliced into and soldered to the existing wiring.
I have an old Kato RS1 in ATSF and added a KT1000 sound decoder with a cell phone type speaker. I even fit a KA1 Keep Alive in the cab. It was an interesting project and one of my favorite locos. The decoder install was pretty straight forward but positioning the speaker and KA required some planning and I must admit some trial and error.
Marty C
Here is a link to the NCE DA-SR at Tony's Train Exchange.
http://tonystrains.com/product/nce-da-sr-decoder/
Perfect fit for the Atlas RS-1.
jecorbett Mark R. It doesn't look like this ? .... https://www.flickr.com/photos/frankzappai/16431918649/ Mark. That is exactly what it looked like. I tried to cram the Digitrax decoder behind the motor (to the right of it in this picture). I managed to squeeze it in and still get the shell back on but it was pushing down on the powered truck to the point where it forced the wheels closest to the motor raised up. Maybe I should have tried it on top of the motor as NP2626 suggested. I'm going to see if that works if I haven't fried the decoder. Does anyone know a method of testing to see if a decoder is still good other than to wire it to the loco and see if it still works. I tried clamping the lead wires to my programming track and seeing if I could set the address that way. It didn't accept it which is why I think I might have fried it.
You need a load on the motor wires to program, so if all you hooked up were the red and black and it wouldn't program, that doesn't mean the decoder is fried. Only way to test a decoder is to hook it all up and try it - that's all "decoder testers" do - provide a place to hook up the decoder with lights and a motor load so you can see if everything works. The "test" is you selecting the decoder and trying the throttle in both directions, and turning on and off all the functions one by one to verify they work.
These are about the only ones I DON'T hard wire (even with an 8 pin plug, that's usually on a factory circuit board of unknown and sometimes just outright bad design - I remove that stuff and solder the wires in most of my installs, that way I KNOW the wires are connected to the correct locations) - it's just too east to replace the factory 'board' with the decoder, plus that still meets my "remove the factory board" criteria. Newer versions of that same loco do have a regular electrical circuit board with an 8 pin plug - and on those I'd still use the TCS A4X (I use TCS for all my motor only decoders).
richhotrain Here is a link to the NCE DA-SR at Tony's Train Exchange. http://tonystrains.com/product/nce-da-sr-decoder/ Perfect fit for the Atlas RS-1. Rich
This thread reminded me that I had an NCE DA-SR on hand, so I pulled it out and installed it on an early RS-3. Photo below, really easy (you'll see I didn't even cut the clips off the power feeds). I did have to flip the motor feeds when I remembered the LVRR ran these long hood forward.
The NCE instructions talk both about having on-board resistors but also about adding 1k resistors to the LEDs. The instructions say that you need to cut the trace to take advantage of the on-board resistors. Here's a question: do you have to cut the trace if if you simply install 1k resistors on the LEDs themselves? or do you need to do both? in which case I'm having a hard time from the NCE instruction diagram figuring out where to cut.
If anyone wants to see them the NCE instructions for the DA-SR are at https://ncedcc.zendesk.com/hc/en-us/article_attachments/200303669/DASRv35-d-_solder_pads.pdf .
Followup question: on the TCS website's installation photos for the TCS A4x, the guy doing the install simply taped two incandescents to the top of his circuit board and separated them with an electrical tape shield--a pretty elegant and simple alternative to pulling out the light bars, cutting them, polishing them, possibly adding 2pin connectors to separate the shell from the chassis, and then after all that getting everything to fit. His photos are at http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Atlas/RS3/atlas_rs3.htm .
I don't have any incandescents that are that small on hand, but I might try to do the same thing with 3mm LEDs that I do have. Hence the question about the resistors and cutting the NCE trace. If I leave the DA-SR trace alone and wire 1k resistors to each LED, will it work?
thanks as always for the help.
JimT [snip] The NCE instructions talk both about having on-board resistors but also about adding 1k resistors to the LEDs. The instructions say that you need to cut the trace to take advantage of the on-board resistors. Here's a question: do you have to cut the trace if if you simply install 1k resistors on the LEDs themselves? or do you need to do both? in which case I'm having a hard time from the NCE instruction diagram figuring out where to cut. [snip] Followup question: on the TCS website's installation photos for the TCS A4x, the guy doing the install simply taped two incandescents to the top of his circuit board and separated them with an electrical tape shield--a pretty elegant and simple alternative to pulling out the light bars, cutting them, polishing them, possibly adding 2pin connectors to separate the shell from the chassis, and then after all that getting everything to fit. His photos are at http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Atlas/RS3/atlas_rs3.htm . I don't have any incandescents that are that small on hand, but I might try to do the same thing with 3mm LEDs that I do have. Hence the question about the resistors and cutting the NCE trace. If I leave the DA-SR trace alone and wire 1k resistors to each LED, will it work?
[snip]
okay, I answered my own question(s) today, and here are some photos in the hope that someone in my position in the future will benefit from seeing photos of how it works. Also the OP might try this decoder and do the same thing I did in terms of lighting.
Top photo shows the LEDs wired in directly to the board: no connections to the shell, no cutting the light bars, nothing extra. Just bend the LED wires to fit, put a resistor on the anode side, and insulate well.
You DO have to cut the trace at "output 2" on the NCE DA-SR board for LEDs to work, even with adding your own resistor (which makes more sense to me now in hindsight). I actually used NCE's online manual for the decoder, which is much much clearer than the faint xeroxed pages that came with the decoder. It became much more obvious where to cut and everything worked just fine.
The second photo shows the black electrical tape to mask the backsides of each LED so they won't show light in both directions while moving either in forward or reverse. This was pretty easy to do, and then I taped everything to stay in place with kapton. It all fits very easily in the space between the light bars in the shell.
The final photo shows the reassembled engine with headlight on. Having both the onboard resistor plus the 1k probably reduces the light output somewhat, but I think it looks pretty good. The handrails took a bit of a beating, I had the shell off and on several times, so I'll have to repaint those at some point.
Anyway, I think this is a pretty easy method for lighting the older Atlas RS3 without having to make any modfications whatsoever to the lightbars. Hope this helps.
davidmbedard You may consider turning OFF BEMF as an option. Sometimes technology gets in the way.... A fine runner like this really doesnt need BEMF on....give it a go. David B
You may consider turning OFF BEMF as an option. Sometimes technology gets in the way.... A fine runner like this really doesnt need BEMF on....give it a go.
David B
The OP didn't say what Digitrax decoder he used, but he did say "most basic" which to me means DH123 series - no BEMF. I wouldn't consider a DH165 as "most basic"
The TCS self adjusting BEMF may indeed be adjusting to very little BEMF action, but mine with TCS decoders do run great at tie by tie speeds. I don't think it would be quite that good without BEMF at all. Maybe good enough for most people. They are top notch motors that kato used, but sometimes even Kato has a dud - had one that would just stop at slow speeds. Wouldn't restart unless the motor was turned slightly. Turns out whoever glued the commutator segments must have been having a bad day because there was a huge blob of the epoxy used right on the one segment. Scrapped it off, put the motor back together, adn it was as good as new. (well, it WAS new, it had been purchased and then stored away for 15 years or so until there was a layout to run it on)
JimT JimT [snip] The NCE instructions talk both about having on-board resistors but also about adding 1k resistors to the LEDs. The instructions say that you need to cut the trace to take advantage of the on-board resistors. Here's a question: do you have to cut the trace if if you simply install 1k resistors on the LEDs themselves? or do you need to do both? in which case I'm having a hard time from the NCE instruction diagram figuring out where to cut. [snip] Followup question: on the TCS website's installation photos for the TCS A4x, the guy doing the install simply taped two incandescents to the top of his circuit board and separated them with an electrical tape shield--a pretty elegant and simple alternative to pulling out the light bars, cutting them, polishing them, possibly adding 2pin connectors to separate the shell from the chassis, and then after all that getting everything to fit. His photos are at http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Atlas/RS3/atlas_rs3.htm . I don't have any incandescents that are that small on hand, but I might try to do the same thing with 3mm LEDs that I do have. Hence the question about the resistors and cutting the NCE trace. If I leave the DA-SR trace alone and wire 1k resistors to each LED, will it work? okay, I answered my own question(s) today, and here are some photos in the hope that someone in my position in the future will benefit from seeing photos of how it works. Also the OP might try this decoder and do the same thing I did in terms of lighting. Top photo shows the LEDs wired in directly to the board: no connections to the shell, no cutting the light bars, nothing extra. Just bend the LED wires to fit, put a resistor on the anode side, and insulate well. You DO have to cut the trace at "output 2" on the NCE DA-SR board for LEDs to work, even with adding your own resistor (which makes more sense to me now in hindsight). I actually used NCE's online manual for the decoder, which is much much clearer than the faint xeroxed pages that came with the decoder. It became much more obvious where to cut and everything worked just fine. The second photo shows the black electrical tape to mask the backsides of each LED so they won't show light in both directions while moving either in forward or reverse. This was pretty easy to do, and then I taped everything to stay in place with kapton. It all fits very easily in the space between the light bars in the shell. The final photo shows the reassembled engine with headlight on. Having both the onboard resistor plus the 1k probably reduces the light output somewhat, but I think it looks pretty good. The handrails took a bit of a beating, I had the shell off and on several times, so I'll have to repaint those at some point. Anyway, I think this is a pretty easy method for lighting the older Atlas RS3 without having to make any modfications whatsoever to the lightbars. Hope this helps.
You should not have to cut trhe links if you added 1K resistors. It should have worked at full voltage to the headlight outputs with the resistor. Both cutting the jumper trace AND adding the 1K resistor just means less bright LEDs. If I blow the PDF up enough, it looks like the supplied LEDs are also 1K (they are surface mount types and say "102" on them which means 10 plus 2 more 0's, or 1000). So by cutting the jumper and adding a 1K resistor, you are running with 2K on each LED. Which means they are running on around 5ma. As long as they are bright enough for you, especially with all that light pipe.
rrinker You should not have to cut trhe links if you added 1K resistors. It should have worked at full voltage to the headlight outputs with the resistor. Both cutting the jumper trace AND adding the 1K resistor just means less bright LEDs. If I blow the PDF up enough, it looks like the supplied LEDs are also 1K (they are surface mount types and say "102" on them which means 10 plus 2 more 0's, or 1000). So by cutting the jumper and adding a 1K resistor, you are running with 2K on each LED. Which means they are running on around 5ma. As long as they are bright enough for you, especially with all that light pipe. --Randy
well, I definitely got nothing at all before cutting the trace, but that was with my own resistor added (that shouldn't have made a difference?). Checked them at that point hooked up to a 9v battery and they worked fine; then cut the trace and they worked fine from the rails. At any rate it would surely be a lot easier not to add them, I'll leave those out for the next one--I've got several more of these to go. But the NCE instructions definitely make it sound like they recommend adding your own resistors in addition to the ones they provide, so the instructions are very confusing if that's not the case.
In many ways a dim headlight for a circa 1950 diesel locomotive might make some sense, no? I've got a 1948 Ford F1 with a 6 volt system, and the headlights are dim, dim, dim. Can't imagine a diesel engine of the same vintage had very bright headlights . . . but maybe that's just me making lemonade with lemons I guess.
Really doesn't make sense, unless you had the LEDs hooked up backwards when you tried with the jumpers uncut - all those traces do is bridge around the resistor, it's not a component, nor does it serve to 'control' anything, so if it were already broken, you would have been running through the on board resistor all along. If it were too much current, it simply would have blown the LEDs - however a 1K resistor is generally sufficient, at HO voltages it is less than 10ma to the LED, and they can take 20-25ma. Going even lower is always safe, although TOO low a current level and the LED won't light up at all.
rrinker Really doesn't make sense, unless you had the LEDs hooked up backwards when you tried with the jumpers uncut - all those traces do is bridge around the resistor, it's not a component, nor does it serve to 'control' anything, so if it were already broken, you would have been running through the on board resistor all along. If it were too much current, it simply would have blown the LEDs - however a 1K resistor is generally sufficient, at HO voltages it is less than 10ma to the LED, and they can take 20-25ma. Going even lower is always safe, although TOO low a current level and the LED won't light up at all. --Randy --Randy
actually, that's it exactly, I think you figured it out. I think I DID wire the wires backwards initially, and it had to do with my keeping "front" and "rear" straight on the diagram in the instructions, versus "front" and "rear" the way the LV ran the engine long hood forward. Plus I wired the anode side of the LED to the output pad rather than to the common pad which is where I think it ended up (which confused me initially). But I'm not exactly sure now what I did, when. Anyway, I'm going to get another couple of these decoders, and I'll try it without the extra resistors and compare the two for brightness.