wobbling Bachmann 2-8-4 Berkshire Steam Locomotive

[wjstix]

Two things to check that I've seen with Bachmann engines.

One, they normally have a deck apron that folds down between the rear of the cab and the tender. (In real engines, it allows the fireman to go from the cab to the tender to get coal.) There's a "lip" on the front of the tender, and if you're not careful when putting the engine on the track, the apron can catch under that lip, raising the front of the engine a bit. I always try to fold the apron up first, then put the engine on the track, then reach in with a small screwdriver, toothpick etc. and lower the apron.

Second, it's not unusual for the siderods on a Bachmman engine's drive wheels to get bent in a little bit from the time in the box during the long trip from China. Put the engine upside-down in a foam work cradle and using wires to a power pack to touch the wheels and slowly turn the drivers to see if they "catch" at some point. If so, slightly bending a rod out a hair so it clears will solve the problem.

[dinwitty]

wobble could come from sticky sidegear mechanics, from the driver wheels being off somehow. If you have clipleads, put the engine upside down, probably in its own box or some foamy protections like the Bowser cradle. Put the leads on the tender wheels (left-right) run the engine slowly and watch the wheels for wobbly, or the side rods for stickiness, any rods interfering with others or engine parts. Keep an open mind and give it a hard look, backwards and forwards.

[ATLANTIC CENTRAL]

selector

I'm still not clear on what our friend is seeing.  Does he see the front end of the steamer, or what are called the pilot and smokebox, nosing left and right, or are they hopping up and down?  It matters. Incorrectly seated driver axles, slight quartering problem, bent drive shaft, traction tire improperly seated (if it has one or two), driver not properly centered on its axle, bent axle.....etc.

 

Agreed, more info would be helpful. 

The loco in question does not have any traction tires, and it does not have any sprung drivers, so that rules out any of those problems. 

Being a four axle loco, it can be subject to uneven track.

But obviously a bent axle, driver not square to the axle, or driver not centered on the axle would cause it to "hunt" and "wobble"...

Sheldon

[selector]

I'm still not clear on what our friend is seeing.  Does he see the front end of the steamer, or what are called the pilot and smokebox, nosing left and right, or are they hopping up and down?  It matters. Incorrectly seated driver axles, slight quartering problem, bent drive shaft, traction tire improperly seated (if it has one or two), driver not properly centered on its axle, bent axle.....etc.

[ATLANTIC CENTRAL]

LEOFUTURE

I am the OP, thank for the response. After a few more tests, the wheel part seems to be stable, just the upper part (boiler) is wobbling. still the defective drive wheel?

 

Really the only thing that can make a steam loco wobble is an out of round or out of square driver.

Note to all, Bachmann has more parts now then ever, but many/most warranty problems are handled by full replacement.

Sheldon 

[richhotrain]

LEOFUTURE

I am the OP, thank for the response. After a few more tests, the wheel part seems to be stable, just the upper part (boiler) is wobbling. still the defective drive wheel?

 

On my Thumper, the driver wheels were the problem. Bachmann declined to fix it, claiming that they no longer stocked the parts. So, they replaced the loco......with an entirely different steamer. If your loco is still in production, return it to Bachmann for an exact replacement.

Rich

[LEOFUTURE]

I am the OP, thank for the response. After a few more tests, the wheel part seems to be stable, just the upper part (boiler) is wobbling. still the defective drive wheel?

[ATLANTIC CENTRAL]

richhotrain

 

 

ATLANTIC CENTRAL

 

LEOFUTURE

Hi, I just bought a new Bachmann 2-8-4 Berkshire Steamer, when tested, the first half (boiler) part of the engine seems to wobble on the rail, checked the screws seem to be tight, what could cause it, is it defective?  Thanks!It may have a defective drive wheel, take it back or send it in to Bachmann for a replacement.

Sheldon 

 

 

 

Sheldon, could this be Thumper's long lost brother?  

 

(Thumper was my Bachmann Spectrum 4-8-2 that exhibited indentical malfunctions to the one owned by the OP. It was returned to Bachmann for repair and was never seen again).   

Rich

 

That is why products come with warranties........shame BLI could not help me with my Mikados........

Sheldon

[richhotrain]

ATLANTIC CENTRAL

 

LEOFUTURE

Hi, I just bought a new Bachmann 2-8-4 Berkshire Steamer, when tested, the first half (boiler) part of the engine seems to wobble on the rail, checked the screws seem to be tight, what could cause it, is it defective?  Thanks!It may have a defective drive wheel, take it back or send it in to Bachmann for a replacement.

Sheldon 

Sheldon, could this be Thumper's long lost brother?  

(Thumper was my Bachmann Spectrum 4-8-2 that exhibited indentical malfunctions to the one owned by the OP. It was returned to Bachmann for repair and was never seen again).   

Rich

["JaBear"]

A very long shot, but I have seen on a Bachmann steamer, the engine to tender wiring positioned in such a manner that the locomotive had noticeable nose down, lopsided look, with a bit of a lope. A reposition of the wires cured the problem. It may be worth a look.

Cheers, the Bear.

[ATLANTIC CENTRAL]

LEOFUTURE

Hi, I just bought a new Bachmann 2-8-4 Berkshire Steamer, when tested, the first half (boiler) part of the engine seems to wobble on the rail, checked the screws seem to be tight, what could cause it, is it defective?  Thanks!

 

It may have a defective drive wheel, take it back or send it in to Bachmann for a replacement.

Sheldon

[LEOFUTURE]

Hi, I just bought a new Bachmann 2-8-4 Berkshire Steamer, when tested, the first half (boiler) part of the engine seems to wobble on the rail, checked the screws seem to be tight, what could cause it, is it defective?  Thanks!