2-10-2 Loco - Min curve radius

[woliners]

My Bachmann Spectrum 2-10-2 HO scale Steam loco continually jumps the track on most of my layout curves. I used the 3' flexible track sections on cork bedding on plywood....nothing unusual there.  And I've checked the integrity, alignment, continuity etc of the track and nothing appears amiss. I haven't measured the curve radii, but they are all much larger than, say, the standard, non-flexible 22" curved track sections.  It's a big layout.

Here's what I've observed: I noticed that the valve gear cylinders interfere with the front truck wheels on the curves, forcing them to derail.  But even so, if I remove the front truck, there doesn't seem to be enough "side-to-side" play in the drivers to accommodate the curves and the drivers derail as well.  I also have an older Bachmann 4-10-4 that does not have problems with any of the curves. 

I tried prying the driver wheels out a bit to give them more play but they wont budge so I left them alone....don't want to force anything.  The front truck only goes on one way so you can't screw that up either.  I can't imagine that the 2-10-2 is so poorly designed for curves.  It's a real expensive piece of equipment.  I'm hoping mine is either mechanically defective or there's something simple that I'm missing. 

Is there some minimum curvature recommended for this model?  I haven't seen anything in what little literature I received with my Loco.  Anyone else run into this problem? 

[jonathan]

Woliners,

The minimun recommended radius for the 2-10-2 is 22". Some have reported theirs would negotiate down to 18" radius.

Yours is the first report I've read that had the pilot truck interfering with the cylinders.  This begs the question, Is the locomotive completely assembled?

Look closely at the steam chest. Does it appear to sit at a non-parallel angle to the rails?  Is the shell (boiler) completely screwed down to the frame?

Sometimes, the wheel cover plate, at the bottom, is screwed down too tight at the factory.  Many have reported great improvements to their locomotives by backing out those screws, just a quarter of a turn.

These are just a few suggestions before you consider returning the locomotive for a replacement or repair. 

If you bought it used, it's anybody's guess what may be going on.  Good Luck...

Regards,

Jonathan

[hawaiiho]

I have two 2-10-2 locos. One will handle 18" radius and one will not; same layout. Both work fine on the 22" R
radius oval of the same layout.

[K487]

woliners:

I fully second Jonathan's advice: 

"Sometimes, the (drive) wheels' cover plate, at the bottom, is screwed down too tight at the factory.  Many have reported great improvements to their locomotives by backing out those screws, just a quarter of a turn." 

This has helped me a bunch with my Bachmann Berkshires and Heavy Mountains; it lets ALL the drivers move sideways left or right to their maximum.  When you back out the screws a quarter or so turn, move each drive axle back and forth; if one or more are still tight when moving, back out the nearest screw a little more and test them again.

As info, I've never had one of these loose screws back out on its own and fall to the roadbed.

K487

[rogertra]

Jonathan.

Excellent suggestion to back off the retaining screws on the keeper plate.

I'll give that a try with my heavy and light 4-8-2s as all of them seem a little track sensitive.  I use code 83 No.6 switches as a minimum and they tend to have problems with them.  They also slow down when passing though the switches, even the through route and the loosening of the screw(s) may fix that as well.  i'll report back.

Thanks again for the tip.

[woliners]

Thank folks!  I'll try your suggestions.  I did buy it used so I don't know if it's assembled correctly.  I do tend to disassemble my "cheaper" loco's just to see what makes them tick, but I'm pretty conservative with the more expensive (or higher tech) ones.  I guess I'll have to get my hands dirty on this on and try to figure out the front triuck problem.  Thanks again.

later

[jonathan]

For what it's worth:

Front trucks have been known to be installed upsidedown from the factory. 

Regards,

Jonathan

[Irbricksceo]

Just something I noticed with one locomotive i had bought, if stuff was caught in the axles, the drivers may have no lateral movement, check that they are clean