Any recommendations for someone who does N scale brass steam repairs?

[benderda]

Hi Guys!
 
I am the original owner of an N scale Key Imports Santa Fe 4-8-4 that was built by Yulim in 1991.  It has always been a poor runner as long as I can remember.  I have been tweaking this thing for over 20 years with negligible results.  It currently has a Digitrax DZ143 decoder that I installed.  I can tell from the pilot light on the DCC booster that the loco is randomly shorting and tripping the overload protection.  I suspect that the short is either in the lead truck or the trailing truck, but have not be able to pinpoint which one.  They may both be shorting for all I know.  (There is also enough slop in one of the driver pairs that they also may be the source of a short.)

The loco will also just stop momentarily then proceed.  When this happens the pilot light is not indicating a short so I have been looking for mechanical binding somewhere, usually in the valve gear.  Tonight for the first time, the loco completely locked itself by jamming the valve gear eccentric against the main side rod.  That has not happened before that I can recall.  The thing also "waddles" down the track.  I can't tell if the first two sets of drivers are not at 90 degrees to the axles, or if there is just too much slop in the main axle bearing blocks, but the first two sets of drivers do not appear to be in gauge and do not run at a 90 degree angle to the frame.

Anyway, all this is to ask if any of you know anyone would be interested in, as well as in possession of the knowledge and skills, to do the needed troubleshooting and repairs to make this locomotive a consistent, reliable runner.   I have checked with several online and advertised services and nobody seems to want to tackle this one.

Thanks for any suggestions.

[mmagliaro]

Aw heck.... silence...

Hi.  I sent you a PM.

Is this the one?  http://www.spookshow.net/key484.html

Egad, look at that long motor shaft!  After I got it running again, that would be the first thing to go.

If you can unjam the rods, I would remove the pilot and trailing truck, and run it, to see if that eliminates the shorts.  If so, then some careful testing on those trucks and wheelsets with an ohmmeter will reveal the culprit.  If there is really nothing wrong at that level, then on the engine, they must be wiping or touching something under the frame.   Put one truck back at a time and narrow it down.

Next, I'd take the motor out, and run the drivers with my hand (it looks easy to take that motor out, luckily).   That should let you see where the bind is in the quartering.  If it really is out of quarter, it might involve removing rods, and pressing off drivers.  If a driver has simply slipped on its axle, you might discover you can set it back with a gentle twist right on the engine, and fix it there with a drop of LocTite or epoxy.

As for any wobble, or the wheels not running on perpendicular axes to the frame, well, I'd have to see that to know what I could do about it.
I'm just trying to give you some simple things you can try before you go down the road of an expensive overall repair.

[benderda]

Thanks very much for replying.

Yes, the loco in the spookshow link is the same one.

The rods are unjammed and so far that problem has not repeated itself.

I appreciate the excellent troubleshooting suggestions.  It will take me a while to work through those, but I will get them done.

Thanks again.

[benderda]

I seem to be making some progress.  "Seem" is the operative word here.

I spent several hours this evening playing around with the leading and trailing trucks and after "re-adjusting"  (read: bending) the lead truck so that it stays on the track better when going through the curves the pilot light on the power supply did not flicker once while the locomotive was running.  It appears that the rearmost set of wheels in the lead truck was intermittently grazing the front of the steam cylinders.

However, the loco still "jerks" along as if it were stopping and starting.  And the problem is more pronounced when going in reverse.  So, I need to see what parts are shifting position when the loco changes direction.

Thanks again for sharing the benefit of your experience.

[Dave V]

There are a few people on this board that can and have...  I wouldn't want to speak for them, though, with regard to their current workload.  I suggest reading my thread about the brass engine throwing a traction tire.  There are hints therein.

FWIW, I've had one of my brass apart before.  Quartering drivers is an essential steam tinkering skill for brass and plastic alike.  Just don't break anything and it should all go back together.

[Scott Lupia]

http://www.blakedtatar.com/

Blake, besides being an incredibly talented modeler in all scales, is the best at brass locomotive repair and painting.  Most of John Green's (Bethlehem Car works owner) pilot models shown in the magazine ads are built and painted by Blake.  If you love your brass and want to see it run in tip top shape, send Blake an E-mail.

Scott Lupia

[benderda]

Thanks guys.  I appreciate the suggestions!

@Dave Vollmer -  yes, I've been following your traction tire thread and that's what prompted me to ask for help here.  There are a lot of skilled and knowledgeable people on this forum who are very willing to share what they know.