Completely frustrated with Atlas, Kato pulling and climbing performance

scottmitchell74 Mar 21, 2014

  1. rsn48

    rsn48 TrainBoard Member

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    I'm surprised some one earlier didn't recommend double heading, the only way to increase power and what the RR's do. steep grades on a small layout often aren't as impacting as a larger layout as usually only a couple of cars are going up the grade, the rest of the cars are on the level, but curves do impact performance.
     
  2. Seated Viper

    Seated Viper TrainBoard Member

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    Have you tried the famous BULLFROG SNOT, advertised on this site?

    Regards,

    Pete Davies
     
  3. bman

    bman TrainBoard Member

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    Just give's one an excuse to run a helper on the rear of the train.

    https://www.youtube.com/watch?v=6Q-s4-cjlgo&feature=youtu.be

    One SD60 will pull the 20 coalporters but struggles in the end loops around my water level pike on 13 3/4 radius. So with the 2nd unit helps with that. I just like the way this looks with the unit on the rear.
     
  4. scottmitchell74

    scottmitchell74 TrainBoard Member

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    I will try going the other direction, just to see what happens.

    And, I have Bullfrog Snot on my to-buy list. It can't hurt, I suppose, and the videos I've seen seem to show a product that does help.
     
  5. papahnash

    papahnash TrainBoard Member

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    BFS works pretty good but there is a trade off. The wheels you apply it to have limited power pickup. A six wheel truck should not matter but a 4 wheel truck might.
    Search the board for articles about it.:headspin:
     
  6. MRL

    MRL TrainBoard Member

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    It is the curve with that SD40! You can see it tries to go then slows down again... Almost like the tack is kinked...
     
  7. MRL

    MRL TrainBoard Member

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    Not being mean or anything...
    Your track is kinked look at the joints on the outside track opposite home plate. Where the SD40 stalls the GP 38 tries to do it too. The GP38 also found some more spots going further into the curve.
    You could easily take up that sectional track and replace it with a piece or two of flex track, it would greatly relieve your headaches!
     
  8. scottmitchell74

    scottmitchell74 TrainBoard Member

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    So does that mean the other locos are more forgiving of the kinks/joints problem? Hmmm...I'd hate to tear up track...sounds like a nightmare.

    I will look at that closer when I get home. Thanks everyone for the input, still interested to hear more about this.
     
  9. N-builder

    N-builder TrainBoard Member

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    I would try to solder the kinks instead of tearing up the track. I have a grade on my layout mysels and I always couple at least two locos to pull more cars up the grade anyway with more then one loco it looks more prototypical anyway.
     
  10. PaulBeinert

    PaulBeinert TrainBoard Supporter

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    Have you pulled out your gauge and checked the track and well sets to make certain they are good?
     
  11. Inkaneer

    Inkaneer TrainBoard Member

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    Tsk, tsk, me too!
     
  12. Grey One

    Grey One TrainBoard Supporter

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    On a Positive Note
    A seven car train with four axil power on that size layout looks better, - in my opinion.
    Nice thing about the lack of tractive effort is it makes the Atlas locos good for mid train power. They pick up the slack but if the lead locos stall so wii the Atlas.
    Ya, I am quite certain sharp curves and six axils do not mix.
    Did the stronger locos have traction tires?
     
  13. scottmitchell74

    scottmitchell74 TrainBoard Member

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    None of the American N-Scale have traction tires. The little British Steam does, so I guess that's something, but the LL's don't.
    I'm going to try double/triple headers, among other things.
     
  14. DCESharkman

    DCESharkman TrainBoard Member

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    You have run into multiple geometry issues that are biasing your results.

    First, the steep 4% grade is pretty bad, but when you compound that with a curve, you are dramatically increasing the effective drag on the locomotive. It is either an 18" or a 24" radius curve that has the same effective drag as a 2% grade. So your 4% grade may have as much drag as an 8% grade on straight track.

    Next, I pulled an E8 and a Kato SD40 out to investigate that observation of yours. The issue here is that the E8 unit is almost double the weight of the SD40, and I am comparing a 1993 E8 with a 1990 SD40. Next there is more weight over the trucks on the E8 than there is on the SD40. So that helps give the E8 more traction. While weight is important, is is the amount of weight directly over the trucks that deliver more of the overall tractive effort.

    Furthermore, the E8 is longer than the SD40 and that may actually help on the curve. The lurch of the E8 can help to keep the trucks in better contact, whereas the SD40 can not lurch much at all and will have more binding. While lurch doesn't look very good, it actually can help with curvature because it creates a torque on the chassis that helps to drive the trucks onto the rails. This is where the additional weight on the truck centers helps a bit too.

    Last but not least, the motors are different in the two locomotives with the SD40 having a smaller motor (less driving torque) than the E8.

    These are some reasons why the E8 can do better than the SD40.

    Sorry I have no Life Like locomotives for the comparison. I can say that 3 SD40's can pull a 50 car train up a 2% grade with a radius of 48 inches with room to spare. And 4 Kato SD90's can pull a 130 car train up a 3% grade with no issues as well.
     
  15. LOU D

    LOU D TrainBoard Member

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    Huh???...Sorry,but you're definitely gonna hafta explain that one to me.If a loco is five ounces,the split weight on each truck will equal five ounces...What does it matter where it is? Bet if I go upstairs right now,and weigh any loco,then split the weight over two scales,the split weight will equal the total weight of the loco...Are you saying that on a five ounce loco,if three of those ounces are in the middle,those three ounces mean less than the two ounces over the trucks???
     
  16. Run8Racing

    Run8Racing TrainBoard Member

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    LOU D, this does work. Although not a locomotive, I moved the weights directly over the trucks on my B'mann full dome cars. Now they absolutely refuse to derail, even in tight turns. Although total weight is the same, it seems the wheels "dig in" a bit more. On the locomotive, if most of the weight is in the center, the inner-most axles will be doing most the work. Don't think there is a whole lot we can do about it, though. I really would NOT like to do chassis set-ups on my locomotives like I had to do on my old Stock Car !!!
     
  17. Hansel

    Hansel TrainBoard Member

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    Try metal wheels on your rolling stock. It will cut down on the friction in the trucks.
     
  18. DCESharkman

    DCESharkman TrainBoard Member

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    Lou D

    There are a few things wrong with your approach. First the model of a point weight at the middle of bar supported at two points has the behavior you discuss. But these are distributed weights over the distance between the truck towers, and the model you suggest does not work in this situation. Yes the trucks support the overall weight, but the weight directly on top of the trucks has more of an effect than the overall weight.

    The weight of the locomotive is not in the center because the motor cavity is there, the motor is not as dense and is in rotation while moving so it effect on the trucks is driving the gear towers not adding to the force on the rails. The truck towers see the solid frame material on either side of the motor cavity. If you look at photos of brass locomotives, they stack the weight on the trucks and the rest of the frame is open.

    hallmarkfoldmech.jpg
    This is from the Spookshow site - http://www.spookshow.net/loco/hallmarkf.html , thanks Mark!

    Here you can see that the truck towers are encased in weighted material to put the weight directly on top of the trucks. And look at all the ope space between the trucks, there is very little weight in the driving axles. Next there is some weight in the motor, but it has less effect on the truck towered and the weight that encases them.
     
  19. Run8Racing

    Run8Racing TrainBoard Member

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    DCE, that is much better way of explaining what I meant. THANKS !!! But I still posted it FIRST, Dammit !!! :teeth:
     
  20. scottmitchell74

    scottmitchell74 TrainBoard Member

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    DCESharkman - thanks for your explanation. Very informative, and something that would never really occur to me. Hmmm...when buying locos (in the past) I never stopped to think about all these issues. It does make me wonder what WS is thinking with their 4% grade on 9.75" and 11" curves.
     

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