The NP and SP&S 4-6-6-4 Challengers are here!

EMD F7A Oct 6, 2017

  1. EMD F7A

    EMD F7A TrainBoard Member

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    That is darn disappointing. My first thought is, why not move the traction tire drivers to the center of each truck? Pretty set on getting one anyway just so I can attempt to fix it. Would Be worth it if I can help you guys get yours working better as well! Will see some of my stuff on Nscaleyardsale moves... my train budget for this month is going to the new Hiawatha!!!!!!!!! Good lord I'm excited for that one...
     
  2. Boilerman

    Boilerman TrainBoard Supporter

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    I have one of the second release and it pulls great, or at least did last time I ran it 25 40 ft. freight cars up a 2% grade with no issues.
    I do not remember which drivers had the traction tires, and all my model railroad is in storage again until I find a suitable home to set it up again.
     
  3. MRLdave

    MRLdave TrainBoard Member

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    Glad I'm not alone.....sorta. I hadn't noticed the driver size issue, but that would also explain the problem......the spring loaded truck pushes up on the rear of the set of drivers (or front), which then pivot on the slightly larger middle wheel till the 3rd axle touches, leaving the 2 axles with no traction tires making the most contact.
     
  4. MRLdave

    MRLdave TrainBoard Member

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    Jbonkowski.......is the middle drive actually larger or does it just sit lower in the frame? It would be a different fix depending on the issue. If it's the former you'd need to turn the wheel down, if it's the latter, you'd need to trim the frame or the bearing block to get the wheel to sit lower in the frame. Neither sounds like an easy fix.

    EMD......I'm not sure if the wheels/gears would allow the siderod pins to line up if you swapped, and I think you'd have to swap the two non-traction tired axles vs the center and TT axle.....that would put the "tall" axle at the opposite end of the truck from the TT axle, which in theory would raise that end and transfer more weight to the opposite end.

    The forums have been oddly quiet about the release of the new Challengers. I'm still waiting to get some more feedback on how widespread the problem is. Sending the loco back (refund) is not an option......I really want this loco. Tearing the loco apart (and voiding the warranty) is not an option either. I have a lot of steamers that are relatively poor pullers. Based on the middle driver issue, a quick fix would be Bullfrog snot on that driver.....hopefully that wouldn't compromise the pickup too much. Awaiting more feedback.
     
  5. SP&S #750

    SP&S #750 TrainBoard Member

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    Just a bit of curiousity here, but what's everyone using for a front coupler? My #910 seems to have shipped without one.
     
  6. MRLdave

    MRLdave TrainBoard Member

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    Mine too.....but the exploded parts list shows one????????? I haven't addressed it till I figure out what's happening with the traction issue.
     
  7. SP&S #750

    SP&S #750 TrainBoard Member

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    Oh dear.... I tested mine got up to 23 no slip but it moved slower.
     
  8. DFW Bill

    DFW Bill TrainBoard Member

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    I have just got my Northern Pacific Challenger, #5140. It ran very smoothly right out of the box, although my layout is DC the sound works in a limited manner, very nice. I put 16 Intermountain 40’ boxcars and a NP caboose behind the Challenger. The cars all have MT trucks and Fox Valley wheels. It pulled easily on a level layout, on my Kato Unitrack with about 20% of the curves 15” radius, 30% 19” radius and roughly 50% is 28”, all turnouts are #6’s. Using a MRC 760 for power. It runs the same as my D&RGW Challenger from the 2013 run. No problems, love the detail.
     
  9. Norway2112

    Norway2112 TrainBoard Member

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    I just received my SP&S #911, non-sound version and it too was shipped without a coupler or any little spare parts bag like some engines come with. Did anyone receive anything else in the box other than the engine?
     
  10. ogre427

    ogre427 TrainBoard Member

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    Spookshow's review of the Challenger states:

    "As delivered, there is no coupler on the pilot, however an ala-carte MT coupler for the pilot (to be installed by the modeler) was included with the earlier runs of this model (said coupler was eventually left out starting with the 2013 run)."
     
  11. jlundy46

    jlundy46 TrainBoard Supporter

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    I installed a Z scale coupler on an older run unit (photo). I just got my new run #911 and haven't looked to see if I can add a z scale coupler on the front.
     

    Attached Files:

  12. ogre427

    ogre427 TrainBoard Member

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    Got my NP non-sound unit today, found it caught on frogs. The screws that fastened the caps holding the wheelsets in the lead truck were loose and hanging down. Tightened them with jewelers screwdriver and the problem was solved. Might be worth checking out.
     
  13. Norway2112

    Norway2112 TrainBoard Member

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    Has anyone determined which decoder will work in the non-sound "DCC Ready" versions? I want DCC, but not sound. It appears to be some kind of 6-pin flat plug?
     
  14. EMD F7A

    EMD F7A TrainBoard Member

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    Team, got mine the other day. Wow. Stunner of an engine! I have the slightest limp, but I'll run it a bit more before I give up. Pulled 30ish cars (as many as I had handy) on a loop of Atlas True-Track with 11" radius, I bet more pulling available on broader turns. Good start.

    Sound is.... well, near stellar. Gonna turn down the chuff as it drowns out bell and whistle at speed. Still, boy-oh-boy what a nice looking engine...
     
  15. sumfred

    sumfred TrainBoard Member

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    Just received my Rio Grande Challenger but found a huge problem. It is unable to pull itself up the low hill on my layout. Even my Atlas 2-6-0 old-timer can pull 5 cars up the hill.
    The problem is that the traction tires are lower than the wheel surface, i.e. the grooves are too deep or the tires are too thin.
    Send it back to dealer for refund. The first and second release I had pulled very well.
    Fred
     
  16. Hytec

    Hytec TrainBoard Member

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    Fred, there are different diameter tires on the market. Perhaps Mike and Robin Fifer can fix you up with thicker tires?
     
  17. sumfred

    sumfred TrainBoard Member

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    Thanks Hank but I've already send it back to the dealer for refund. I am not willing to repair a new $450 engine.
    Fred
     
  18. mmagliaro

    mmagliaro TrainBoard Member

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    I have done some work on one of these for a friend. His also had the problem with the thickness of the tires.
    The tires are are thin enough that the metal rim portions of the treads stick out further than the rubber tires - hence, no traction.
    Also, the tires are NARROW. They are too narrow, in my view. Nothing can be done about that without removing the drivers and machining the grooves wider. They are also not consistent. The groove on one side of the engine is noticeably wider than on the other.

    Be that as it may... I pulled the tires off on the rear engine truck, cut a thin strip of masking tape with a razor and straight edge, wrapped it around the driver down in the bottom of the groove, and then put the tire back on. This gets the tire to ride just a little more "out" on the wheel. That solved the pulling power issue. The engine went from being able to pull only 13 cars up my test grade (1.7%) to pulling 28 without a hitch and it could certainly pull more. I don't know the limit.

    Since some of you are seeing this problem and some not, this sounds like a QC issue with these engines. Perhaps the
    driver grooves are not consistently cut, or the tires themselves are variable in thickness.
     

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