MTH Steam with two wheels trucks derailing on Fastrack switches

 When I was young, this happened with steamers with 2 wheeled lead trucks more often? I would have thought 4 wheeled would have been worse? I would stay away from them. I didn't know how to solve it.

 I've learned that the trucks spring tension must be correct. Wheel spacing if off, will pick the switch or jump at the frog. Etc. Check that stuff first.

 What I would also do is run or push the engine very slowly through the switch to see if the pilot is having difficulty with a certain switch's profile. Sometimes sharper cut wheel rims, will pick an open switch's leg's gap.

If it only jumps at certain speeds, I would add pressure to the spring system pushing the pilot down. You could just try adding a little weight to it to see if that helps.

 I hope others have better ideas and this gets solved for you. I'm mainly a diesel guy!!

 I have since purchased a MTH Pacific and it runs great through my Atlas 2 rail layout thankfully.

Whats the minimum curve radius of those locos and what is the degree of the switch?

If you exceed the min curve radius that can happen and will.

I would agree that I would look at the gauge of the front tr4uck wheels since if that is off too much then the front truck will jump every time. If that is okay then try a stronger spring or some little wheel weights on the front truck if there is room.

I have an experience with a RK 2-8-8-2 and a Premier 2-8-2, both of which would 

derail the front (and rear in the case of the Mallet) on my Gar Graves switches, and

I fixed it by increasing the size of the pivot "post" where the truck screw goes into

the frame to attach the truck. The original post is so slim - I think that a bushing was

skipped in assembly in the case of the 2-8-2 - that it allows the truck to "wallow

around" at the supposed pivot point, causing the wheels to hit the switch at an

angle, and just generally hunt back and forth.

I got some brass tubing of a size that would fit snugly over the cast-in pivot, enlarging

it and reducing the wallow. Fixed it. Cut it to the same length as the cast-in part and

slip it on - use some Goo or silicone to hold it in place if it wants to slip off.

For what its worth my MTH Madison Heavy weight passenger cars derail on every Fastrack switch. Seems they experience a "bump" depending on the direction into the switch other cars do not experience.

On two wheeled pilot trucks you need to increase the tension on its spring, be sure the gauge between the wheels is correct, and keep the corner of the wheel clean of crud build up; that is where the wheel surface meets the flange.

.....

Dennis

if the berk is scale it would not run on 0-36 anyway.

tell your brother to come here and clarify some of the questions

My issue turned out to be the plungers on my Williams 027s and some MTH 60' cars. 

My RMTs 0-27s do not have plungers and are fine, as are my MTH Premium Woodsided cars.

I had this same issue with my PE Berkshire.. I increased the spring tension and all is good now..

Matt