Weird Reverse Issues.

What do you mean throw in reverse? Just change direction?  What speed is the engine jerking at?  G

Yes, change direction. And any speed, whether 5 smph or 15, It continues to do this for about 15 seconds before it works itself out.

I'd look at the tach tape and check the spacing of the tach reader to the flywheel.

I've checked the spacing too, and it is sitting right at 75 mm. Wouldn't loss of tach signal and regain of the signal cause the engine to speed up and slow down?

I think the tach tape would effect both directions if it was gap issue.  This only does it after long runs in fwd, only last a short period.  I wonder if you ran it for a long period in reverse if it would jerk in forward for 13secs.  Harder to do with Steam.

 

Certainly the motor armature and gear lash shift some in reverse from forward, but that would happen all the time.  Sounds like some heat related issue which could be the Motor FET.

 

Do you have another steamer you can put this board in and retest.  If the problem follows the board, it helps eliminate the engine wiring, motor, tach etc...

 

At that point it would lead me to the motor driver circuit.

 

If the problem stays with the engine, then we can look at wiring and location, and the motor as possible issues.   G

I have others, but I'm not sure I really wanna take the time to swap a board to test this. I'll probably get to it today because were all snowed in I ran it for a good amount of time today, changed direction, and everything was fine. 

I've seen these types of encoders read one way better than the other, that's why I suggested it.

 

I just put the engine through its paces, forward and reverse, and the issue did not occur.  

I'm inclined to suspect a non-DCS issue, mechanical in nature.  I am not sure what ESE is. If it is steam, check the side rides for looseness or binding. Whether steam or diesel, make sure that the screws holding the can motors to the gearbox(es) are tight. If it is loose, the worm gear could be jamming.  You could also remove the motor(s) and inspect the gearbox for loose impedimenta.

Welcome to Train troubleshooting of non conforming issues!

RJR, The Engine is a Railking Empire State Express, (ESE). As stated in my initial post, the gearbox, siderods, and worm gear have already been inspected and are in good working order.

When reversed, the motor shaft slides upwards or downwards.  This end play can affect the gears.  It might not show up unless loco is under load.  Mechanical issues can be real tough to locate.

 

 

Sloppy(loose) fly-wheel?

RJR has an excellent point, and one that you might explore farther.

 

RJR does indeed make an excellent point. However I can't get the loco to misbehave today!!

Ghosts?

Be thankful.

 

One other thought.  A rolling stock wheel could have been off the tracks unnoticed, and occasionally shorted.  Or some bit of detritus could have been caught on a pickup roller.  All these I have experienced.

I made that same comment concerning gear lash, but did not explain it as well as RJR did.  You can watch the flywheel move with the shell off.  G

Well, if it occurs again, I'll look into it. Everything seemed fine all day.