400E issue; looking for a solution.

"Video is unavailable" when you hit play or go to YT

See if it works now.

Thanks,

Scott

Bring it back up the next time you are that way.  l'll look at it.  I'm the tinplate guy at MTH, but I only work Monday & Friday.  

Jon,

Did you look at the video?

I'm certainly no expert here. I have seen this happen with everything from a single loose motor mount screw, to a valve gear assembly that got bent just enough to cause a bind issue. I usually find the problem by turning the motor flywheel by hand for binding issues, or running the engine on the bench where the valve gear stays put to watch it closer. Even then I still turn the motor by hand.

 The only thing I saw in your video was some type of binding causing a lurch, on certain turn movements. I'm not used to all the extra noise from the track and rollers.

I'm sure you looked at the basics like the traction tires are in place, etc. I think this should be an easy problem to find. I have been wrong plenty of times!

Is the motor (and/or tach reader) firmly attached so that there's no movement?

So I'm no expert but I noticed two things -

Both incidences I saw on the video occurred in the same location, just before the locomotive crossed onto the bridge.

To my untrained eye, this is not a mechanical issue.  The locomotive runs too consistently around the track at all other points.  To me it looks like there's an electrical surge of some sort taking place that makes the engine speed up momentarily.

Just my $.02.

That was what I was thinking, until I moved it to a different track and had the same issue. I also have 3 other 400e’s and none of them have the same issue.

Scott Smith

Scott,

Interesting video.  I looked at several times and indeed it sounds like a momentary surge of some type.

But I have a couple of questions.

1. Does this surge take place on curves more frequently than on straight sections?  If so, on the left or the right?

2. While watching it very closely, did you happen to notice if the rear wheel set is the one that tends to lurch forward?  Look closely at the rotation at that moment.

3. Can you artificially induce the surge in anyway?

I'm suspecting that one of two things: A. One of the wheel sets is becoming momentarily disengaged which allows the motor to speed up as the load on it has been reduced.  Check for proper alignment of the wheel sets, the bearing may be offset or out of round.  B.  Also check the motor itself, there may be a physical issue with it.  Make sure its tight and without a lot of play. 

I do not own one of these, so its hard for me to determine from my vantage point what it may be exactly. 

Can you produce a video with a close up of both sides?  I'd like to see and hear it again.  Also please increase the lighting as it was not bright enough for me to see what was going on.

Thanks!

scott.smith posted:

... N&W 400E.

*sigh*

It's on it's way back to Jon at MTH. We had a nice discussion about it, he has some idea what might be causing the issue. I have 13 other standard gauge locomotives so there is plenty to run while I wait for the repair. Thanks for all the feedback.

Scott Smith

Let us know how you make out with it Scott.  Nice to live close to headquarters at a time like this!   Good luck. 

I'm a 5 hour drive from MTH; however they are one of my customers. So anytime I visit it is a tax write-off as long as I discuss their services while I am there. I used Fed-Ex to send the train since I was just there last week.

Scott Smith

I was told that some of the more recent Bild a Loco motors have armature plates that are out of spec and sometimes rub against the inside of the field plates (metal on metal). Jon has a fix for that.

If the gear teeth are slipping between the two driven axles, it won't run for long.

Jim