Model Railroading > Athearn Ho scale #4014 Big Boy question

  My son has a new 4-8-8-4 Big Boy that is new in the box. We have'nt had a chance to run it until the wiring was finished. On Sunday we finally got that chance, it runs great on straights but on the curves the tender comes off the track. The first 2 axles behind the truck. My radius is a max of 36 and a min of 32. He took it home so I can't work on it until he comes back over.  I will check the wheels to see if they are all in gauge. This is the latest release the number is 4014. If they are ok, then i'm lost. Any Idea's ?

  Thank you 
  Steve H...



Edited 2 time(s). Last edit at 05/17/19 08:18 by hartrick24.

Their earlier Challenger with the pair of 6 wheel trucks had every axle too wide by the width of a flange.

Chevck the gauge and make a couple in the middle of the rigid set blind.

I was told these need a 36" minimum radius but I don't own one to check. Curious what you come up with on this.

trackplanner Wrote:
-------------------------------------------------------
> I was told these need a 36" minimum radius but I
> don't own one to check. Curious what you come up
> with on this.

  I spent some time on Athearn's web site searching with no luck hoping they would have it. 

  Steve H

Hi Hartrick,

I have an early version of the Athearn Genesis 4-8-8-4.  Also have a 4-6-6-4 and three 4-8-4s, all of which have the centipede tenders.

I have run my locomotives successfully on less than 36" radius curves specifically 30" radius. The larger the radius the better they look on the curve.

In fact the manual (page 4) with the Big Boy states "Front and rear engines (cylinders and coupled drive wheel sets) both pivot in order to manage 18" radius curves."  In my opinion it would look ridiculous doing so. 

In your original post you mentioned the tender derailing. 

I would definitely check the gauge of the wheelsets.  Also be sure to check that all of the axles are properly seated in their locations, especially in the five axle truck.  Also make sure the axles are free to move laterally in their positions.  A bit of flash or a wheelset that is not properly seated or gauged will cause problems with derailing on curves.  Good lighting and some magnification would be most helpful for the inspection.

With 36 and 32 inch radius curves the locomotive and tender should go around the curve smoothly.  Another thing to check would be the curve in the area where the tender has derailed, if there is a kink at a rail joiner that can be problematic for large locomotives and their tender.  A bit of solder from a drop sticking above the railhead can also be problematic.  Might be worth a try to move the tender through the curve without the locomotive and see if it still derails.

Don't ask how I know about kinks and drop issues.  Too many years spent maintaining a large club layout to overlook those possibilities.

Hope this is of some help.

Cheers!

Bob


hartrick24 Wrote:
-------------------------------------------------------
> trackplanner Wrote:
> --------------------------------------------------
> -----
> > I was told these need a 36" minimum radius but
> I
> > don't own one to check. Curious what you come
> up
> > with on this.
>
>   I spent some time on Athearn's web site
> searching with no luck hoping they would have
> it. 
>
>   Steve H



Edited 1 time(s). Last edit at 05/15/19 00:28 by up421.

I have the same 4-8-8-4 engine and it runs well on smooth consistent 28” curves.  I suspect you have a small kink
or vertical whoop de do causing this problem.  Even a slight variation in gauge or radii can cause a big
engine/ tender such as yours to have issues.

These engines run really well and the sound system is good too.