How effective is it pulling with two units?

rva1945 Oct 17, 2016

  1. rva1945

    rva1945 TrainBoard Member

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    I'm talking about models, not "real" trains.

    They're motors and gears must be precisely matched, otherwise. the unit with less traction power it will slow the other down.

    I'm still waiting for the FT-B unit to arrive, it is powered and analog. There are a couple of wires coming out from the A's motor terminals so its decoder will drive both motors.

    But I'm serioulsy considering stripping the B from the motor and gears and leave it as a dummy B unit. I have F7 A and its dummy B unit and it pulls the freight train effectively.

    What would you do?
     
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  2. acptulsa

    acptulsa TrainBoard Member

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    To some degree, it can depend on your power supply. Sometimes one motor pulls better than two with the same amount of power, just because of the characteristics of the power pack. To some degree it depends on how heavy the train is; some trains just require the extra tractive effort to get moving. But matched locomotives with the same motors and gearing generally pull well together.

    Locomotives are weighted so they will get enough traction to pull their weight, and often at least some of this weight is built in and difficult to remove. If you want one powered locomotive, order the rest of the lashup as dummy units, as they are liable to replace metal parts with plastic parts. Otherwise, you may find your power unit-turned-dummy is so heavy that adding it to the lashup cuts the number of cars the powered locomotive can haul by as much as half.
     
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  3. Hytec

    Hytec TrainBoard Member

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    I run multiple units on DC with no ill effects, even some of different manufacture. I run two Atlas Classic RS-1s together, one by Kato and one by a company in China, with no problems. They operate at different speeds, one slower than the other, but they keep each other in check and effectively double pulling power. I need both to pull my Roco track cleaner, whereas neither can pull it alone. I also have a Kato F-3 ABBA set, all powered, that run together very well, growling along at low freight speeds with 38 cars. Though I'll admit they pull about an amp of current in this configuration, which is fine with the MRC Tech 4 supply, it doesn't even flinch. (y)
     
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  4. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    About the same here, no problems running two or more DC locos in MU. It's preferable to have the same make of engines through the consist, but mixing certain makes, like Atlas and Kato (some Atlas have Kato drives) is not a problem. Slight differences in running are usually evened out, and a decent power pack will power the lashup easily.

    Dummies need to be weighted accordingly, though, or they tend to derail.
     
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  5. acptulsa

    acptulsa TrainBoard Member

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    Absolutely. They need to be heavier than cars, because their longer wheelbase trucks don't help their flanges hold the rail when there's a lot of weight behind them. But they need to be lighter than powered locomotives, or they have a real bad effect on performance.
     
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  6. CarlH

    CarlH TrainBoard Member

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    What would I do?
    I would just try the simplest thing first: couple the new loco to the old one and see how they run when coupled together.
    I have not had any particular problem doing this in my non-DCC layout in years past.
    I would guess that problems are more likely if there is a bigger difference in the speed the two locos would run, with the same voltage.
    I don't think they have to have an exact match - give it a try.
     
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  7. montanan

    montanan TrainBoard Member

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    I operate DC only. I am a lone operator and my layout is built mainly for switching so I really wouldn't gain much by changing over to DCC. I rarely run more than on locomotive at a time and when I do it is usually when using a second locomotive as a helper. The majority of my locomotives are the original Atlas Alcos with the Kato drive that came out some time in the 90's I believe. These locomotives all run at almost the same speed so I have no problem using a second or third locomotive as a helper.



    What you could do is try to find two locomotives that run pretty well at the same speed or closle to the same speed. Put the fastest of the two locomotives in front of the slower one and you should be able to pull a good size train.
     
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  8. gjslsffan

    gjslsffan Staff Member

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    I too am DC only with no plans at this time to convert anytime soon, DC works just fine for me. And less expensive.
    I offer the following video, all DC, and this video has a DP powered unit, all sound is recorded from real locos and recorded while the vid was recorded. So it can be done small or large trains, there has been some really good advise offered here. We need a DC thread I think.

     
    Last edited: Oct 18, 2016
  9. rva1945

    rva1945 TrainBoard Member

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    You can buy an Arduino UNO and its L298 shield (power booster) for less than $10.
    Download and install the IDE (development interface), free
    Download DCCpp project, free (that is the code to load into the Arduino).
    Download and install JMRI the java interface to program, manage rosters and throttles for your locos.
    Install Engine Driver from Google Play into your Android device, link it to JMRI via your network and you alreado have your DCC base station, all for less than $10.

    Ok then you have to convert your locos to DCC. I think it is worth the effort and try (and learn!) new things.

    There are thousands of sites and videos with all the info and guidelines for this.

    No more electric blocks in your layout. Well, I have a length of it that works as the programming track.

    Just my two cents.

    Robert
     
  10. BarstowRick

    BarstowRick TrainBoard Supporter

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    I learned along time ago that a dummy unit is just that a dumb thing to buy.

    Keep your locomotives powered and if using DCC use a separate decoder for each unit. Works great! That is if you know how to set-up the CV's.

    Should you choose to stay with Analog DC you can use resistors to slow a motor down to match the other's.

    Every generation of toy train enthusiast or model railroader has to go through the same learning curve. The same lessons.

    Just hang in there it will all come together.
     
  11. rva1945

    rva1945 TrainBoard Member

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    Will setting both decoders to the same address? Should I make both locos run uncoupled at the same time and change motor parameters until they respond almost identically to the common throttle?
     
  12. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    I'm sticking to DC - I have 76 powered locos and 16 unpowered. The cost of converting all that stuff to DCC would be enough to buy a decent used car. The work involved in putting decoders in some of these locos (most are from before "drop-in") would cause enough cussing to fill a 100-ton hopper. So the whole thing would be not only costly, but quite unpleasant.

    Since I'm a cheap old bugger that really likes playing with trains, it would be contrary to both basic principles.

    A couple of years ago I bought an Arduino Uno for some other projects (including a computer-controlled DC throttle, to be eventually Bluetooth linked). After messing about with the blink sample program, it went on the shelf since then. Recently, I've taken it off the shelf again and have another project in mind (there's plenty of fun to be had with these gizmos).
     
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  13. BarstowRick

    BarstowRick TrainBoard Supporter

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    Learn to "Consist" you locomotives. You can set them both to the same number but you'd be better off to give them each their own number and then learn how to consist them. Keep a paper trail a log of sorts so you can remember what you set each motor to.

    Most of us will use the number on the unit unless we happen to run motors with the same numbers. Then we use three numbers which can be the first or last ones.

    Not as bad as you might think.
     
  14. jdetray

    jdetray TrainBoard Member

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    If you properly consist your locomotives using the "consist" features of your DCC system, you get nice effects such as correct illumination of headlights on both locos.

    Speed matching is a whole separate discussion, but yes, your description of running locos uncoupled until their speeds are matched is a good approach.

    - Jeff
     
  15. CraigN

    CraigN TrainBoard Supporter

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    When I strictly used DC power , I would have my faster engine coupled to the train and the slower one out front.

    In my mind I figured that the faster one slowed down enough from pulling the weight that the slower one was now the faster one and actually helped pull the train and was not part of the train the other way around.

    I never did any pulling tests to see which way pulled more cars and I never had any issues with worn out gears.

    I'm not saying my way was better , I'm just saying how I did it back in the day of DC for me.

    Craig
     
  16. Ike the BN Freak

    Ike the BN Freak TrainBoard Member

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    I don't think so, depending on your DCC system, it can only handle so many addresses. So let's say you have a consist of 5 locos, each with a different address, this consist will use 6 slots.

    I set up my consist using the same address, normally the lead unit, and that way, my consist only uses one address slot, regardless of 1 loco or 87 locos. Also doing it this way, it makes it easier if you program locos to run at home, and then take them to another layout or club, there isn't the need to set up the consist again.

    Being I use JMRI, I program off the lights on trailing units, and rear headlight on the lead and trailing units.
     
  17. Ike the BN Freak

    Ike the BN Freak TrainBoard Member

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    duplicate post
     
  18. montanan

    montanan TrainBoard Member

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    I don't have quite as many locomotives as you, probably somewhere in the mid 30's and the thought of converting to DCC is not an option. I am modeling the transition era and the majority of my custom painted fleet of Alcos from Atlas are the first ones they brought out with the Kato drive. There is no room at all in them for a decoder let alone a speaker and the work it would take to convert even one locomotive turns me off.

    I am a lone operator and my layout is built mainly for switching and I rarely have the need to run more than one locomotive at a time except for a helper as in my video posted earlier. A very good model railroader friend from out of state who is a DCC nut even admits that for my layout, DCC would be of no advantage. I do have I believe three DCC locomotives with sound. One was a gift and the other two were locomotives that I had been looking for and could only be had in DCC. Sure wish manufacturers would give the buyer a choice and also make DC versions available,
     
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  19. BarstowRick

    BarstowRick TrainBoard Supporter

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    I really don't care how you set up your locomotive designations on your model railroad. Just thinking out loud as to what can happen should you visit a local club that uses DCC and you are the odd one out. Worse yet someone is already using the number you are. On the other hand, should you start having problems and you find yourself troubleshooting an impossible situation. You'd be better off to use a individual number for each locomotive. Narrows the field down when looking for the problem unit.

    You can set a group of locomotives to the same number if you desire. In most hand held controllers you can store up to 99 different locomotives. The problem here is if you loose sight of having done so as in no paper trail or log there's a good chance you'll have locomotives moving around all over the layout. You won't be able to shut each one down.....separately.

    Real men don't follow instructions. If you follow the instructions that come with the decoders and your DCC power supply you won't have some of the problems that have been shared here.

    You'll hear me say from time to time. Don't short cut the process. It will only backfire on you.

    If you need help discerning the whole DCC process you can go to my website which will then redirect you to David E., DCC Guy, Powersteamguy 1790 and other knowledgeable advisors.

    I belong to a group of model railroaders who use DCC exclusively and I opeerate, troubleshoot and otherwise have hours of fun operating trains. Sad to say DCC has taken second stage on my layout as the cost is prohibitive.

    Use DCC the way it's been designed to be used and it will work well for you. Just don't expect perfection from it.
     
    Last edited: Oct 19, 2016
  20. rva1945

    rva1945 TrainBoard Member

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    My first experience combining Arduino and trains was a DC control. It works in manual or auto mode. In auto mode, it detects an IR sensor and stops the train for a while. Maximun speed, minimun speed, acceleration/deceleration and stop (at the station) times can be set by potentiometers. If you want the code to study ir and eventually use it, just let me know. To my surprise, without any hint on what decoders were and how they were programmed, I ended creating the same basic motor parameters any decoder has.

    Regards,
    Robert
     

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