Athearn Blue Box U33C and SD9 Rocks Too Much

Flash Blackman May 6, 2013

  1. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    I have an issue with two newly acquired Athearn Blue Box engines. They rock too far to the side. They always right themselves; they do not lean when standing. As far as I can tell, this is caused by a small king post plus the surface contact area on the truck bolsters and the frame where they contact. Other BB engines have a much larger area to contact. I would say this engine has a contact diameter around 5/16 inch whereas the regular Athearn BB is around one-half inch. Seems the frame is made of lighter material than the normal engine. In fact, I have wondered if this is actually a BB engine. Also, I have an SD9 which is the same way.

    Anyone ever see this before? The engine runs fine; I have just converted it to DCC.

    (Seems strange; just wonder if I am crazy.) Thanks.
     
  2. 2slim

    2slim TrainBoard Member

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    Flash,
    I would also wonder if this was a Athearn frame. I know that Rail Power Products made a couple of frames for some of their shells. I was under the impression that the RPP frames were designed around Athearn trucks. Perhaps find a very thin stainless washer or shim about 1/2" diameter? I have never heard of anyone having this problem with Athearn frames, curious are they both blue box?

    2slim
     
  3. Flashwave

    Flashwave TrainBoard Member

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    Odd, I've seen this in freight cars where the weights slightly off (the fat hobo syndrome) I think your right, It sound like either you need a wider footprint on the top of the truck and/or the bottom of the engine to contact. And probably, its being caused/exasperated by the vibration of the motor and or slight irregularites in the track. Not sure how much clearence you have there though. A washer is a good idea, although you want something that will go around a the kingpost and not thicker than the space between truck and frame, otherwise your loco will ride too high and it seems to me like the SDs have enough of that problem already. You ewant to widen the base, much like a wider tripod is more stable. Putting a washer ON the Kingpin will make the issue worse. The club has a few BB SDs, I'll check 'em out to see if they rock at all. Casn you tilt the engine when its sitting still by pushing the top over slightly?
     
  4. gjslsffan

    gjslsffan Staff Member

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    I have this issue with BB Athearns as well. If you look at the clips that hold the truck to the frame while the loco is sitting on straight level track, you will notice a large gap between the clips "fingers" and bolster. What I have done in the past was use styrene and shim that so there is ample room for normal operation. used ACC to glue the styrene shim to the frame. I have had no issues with the drive lines hitting the styrene, but you might check that out too.
    Hope that helps.
     
  5. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    You can tilt it, but it returns to normal, no problem. These two engines will tilt much further over than my other Athearn BB engines.

    The idea that it is a RPP frame may be correct.

    Thanks for the help on this.
     
  6. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    I finally figured it out and this is exactly the problem. I used styrene to form the shim and attached it with bathtub caulk. No problem with the shim hitting the drive train.

    Also did some measurements:

    Normal spacing in an Athearn BB is .005 inches.

    One of my engines had a .030 inch gap. I used .025 inch styrene shim to correct this.

    The other engine had .025 inch gap and I just used .015 inch styrene on this one.

    I will test the engines tomorrow. Thanks to gjslsffan for the specific information and the others who responded. Some of the guys at the club helped, too.

    Here are some photos, one before the shim and one after the shim. Athearn shim 002 5-11-2013 5-10-11 PM.jpg Athearn shim 001 5-11-2013 5-30-58 PM.jpg
     
  7. gjslsffan

    gjslsffan Staff Member

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    Thats great,
    I am glad I was able to be of some help. Looks to me like that is indeed an Athearn U-C frame, the factory headlamp mount tab on the front of the frame is a familiar sight. That old Athearn BB stuff will just about run forever with a little TLC. You will enjoy it for a long time.
     
  8. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    One more thing...I seem to get a similar rocking problem if the wheel gauge is too wide. It doesn't have to be but a very slight amount too wide, either. I think that is caused by the axle trying to climb out of the track gauge rapidly on alternate sides.

    Right you are, gjslsffan about the Athearn BB. I had a five engine lashup running this afternoon...SD40T-2,SD9, U33C, SD40T-2, and GP60. That will really pull some cars.
     
  9. JNXT 7707

    JNXT 7707 TrainBoard Member

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    Flash - this is the thing I've been wondering about lately, concerning lashups. Not sure if you run DC or DCC (or if it matters), but how many powered units can you run at once? Or more to the point how can you determine that number?
    I've been running 2-unit powered lashups like crazy ever since I figured out I could do that with DC (duh!), and now I'm thinking why not 3 or more? Not that I really need to, but you never know when I might ;)
     
  10. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    Jerry:

    I run DCC in H0 scale and I use the speed tables to match the engines. I expect you could do it in DC if the engines were the same make and model. Even in DCC, I always use the same type decoder in all the engines to make it easier.

    I am unable to program on the main line so I have to use trial and error with parallel tracks for the engines. I do all this at my H0 club as I have no H0 layout or track at home...only N scale. I learned the matching process from the internet and trial and error. Lots of JMRI computer time.

    You can run any number of units once they are speed matched. I have run up to eight. It just depends on how many I bring with me.
     
  11. gjslsffan

    gjslsffan Staff Member

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    I am a DC guy for 30+ years and have consisted up to 13 locos on one cab, but typically we run 4-6 unit head end consists. We will run mid train (swing) and rear helpers on occasion as well, usually on loaded unit trains. Its all in the power pack or power supply, we have 4 MRC Control Master 20's and run them on the G scale setting, they have the slightly higher amp/volts needed to run large consists, but have never hurt any motor, even just running a single loco. You will just need to test your locos and see which ones run best together. Real locos dont run at exactly the same speeds either, EMD's typically load up much faster than GE's, but there is enough tonnage behind them that forces them to work together. I would try to keep locos that go slightly faster towards the head end as you will run into less misery if your couplers are stretched out as opposed to bunched up going thru turnouts and sharper curves.
    Lets have fun out there,
     
  12. ScaleCraft

    ScaleCraft TrainBoard Member

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    I know guys who not only do this, but use old Athearn Hi-F drive units up front, as they don't care about speed mismatch, work very well in that usage.
    Dave
     
  13. JNXT 7707

    JNXT 7707 TrainBoard Member

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    Thanks for the responses all, but what I am asking is how you determine how many locos you can safely run from a power source?
    My current DC layout has two independent loops, one with a MRC200 Tech 4 and the other with a MRC Railpower 1300. As far as power output, the Tech 4 says 15.5V DC, the Railpower 1300 says 15V DC.
    So based on that output, is there a conservative rule of thumb that would tell me how many locos they would run?
     
  14. GP30

    GP30 TrainBoard Member

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    I have ran a consist of 7 units (4 & 6 axle units) before on my trusty, old MRC Tech II / Locomotion 1500. They were just crawling at full throttle. Looked awesome, but I'll be a DCC guy in the near future.
     
  15. JNXT 7707

    JNXT 7707 TrainBoard Member

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    So you more or less can run however many units your power supply can push?
     
  16. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    AFAIK, for DC, you will be limited by the number of amps you can pull with your transformer. Three amp power pack with .12 amps per engine means you can run 25 engines max before the circuit breaker trips.
     
  17. ScaleCraft

    ScaleCraft TrainBoard Member

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    That's right. Volts helps with speed, amps with number of units.
    Let's say, under load, round figure, one amp per loco (I know, I know). '
    Let's say you want to run 7 locos. That's 7 amps.
    Look up the data on your power pack output. If it is capable of 7 amps or more, you're fine.
    Realistically, .3 to .4 amps per loco in Half 0, .3A X 7 + 2.1A. Add a fudge factor (like, oh, lit track end bumpers) and 2.5A will suffice.
    To many amps, it will pull your output voltage down and they will crawl.
    MRC Tech6 2.0 is 2 amps total output, Tech6 6.0 is 6 amps total output, Railpower 1370 is .6A, Railpower 1370 is 1.3A
    In this situation, only the Tech6 6.0 will do.
    Tech4's are ,7 to 1.4A.
    Dave
     
  18. JNXT 7707

    JNXT 7707 TrainBoard Member

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    OK, it's getting clearer.
    Reading the specs of both power packs, the Tech 4 lists total output of 17VA.
    Railpower 1300 lists total output of 7VA.
    I have determined that "VA" means "Volt-amps". Apparently this means that for the Tech 4, at 17 volts it is delivering one amp...and at 8.5 volts it is delivering 2 amps.
    Getting clear as mud now.
     
  19. JNXT 7707

    JNXT 7707 TrainBoard Member

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