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Hi there,

I'm modelling in N Gauge but I think this might be a problem which other gauges have encountered, hence placing this post in the Station Concourse where all might pick up on it.

Although I don't have a layout to run my locos on yet, I have been programming the chips on a 1 metre length of track (Code 55) and then gently running them in on a rolling road. Among my stable are 3 No. 2-6-2 Praires (2 Dapol and 1 Graham Farish).

The GF and one of the Dapols perform flawlessly, as do the rest of my locos, but the other Dapol staggers drunkenly both down the track and on the rolling road with a side-to-side motion.

Does anyone have any idea what might be causing this and what the remedy might be ?? I suspect it might be a back-to-back wheel spacing issue but haven't checked that yet as it will require dismantling the loco.

Thanks in advance for all help and advice,

Expat.
 

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Just another modeller
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QUOTE (Expat @ 7 Oct 2008, 18:38) <{POST_SNAPBACK}>Hi there,

I'm modelling in N Gauge but I think this might be a problem which other gauges have encountered, hence placing this post in the Station Concourse where all might pick up on it.

Although I don't have a layout to run my locos on yet, I have been programming the chips on a 1 metre length of track (Code 55) and then gently running them in on a rolling road. Among my stable are 3 No. 2-6-2 Praires (2 Dapol and 1 Graham Farish).

The GF and one of the Dapols perform flawlessly, as do the rest of my locos, but the other Dapol staggers drunkenly both down the track and on the rolling road with a side-to-side motion.

Does anyone have any idea what might be causing this and what the remedy might be ?? I suspect it might be a back-to-back wheel spacing issue but haven't checked that yet as it will require dismantling the loco.

Thanks in advance for all help and advice,

Expat.

Hi Trevor

When N is out of whack its a serious wobble!

Try stripping the drivers out of the chassis.

Polish the ends of the channels in which the drivers run - don't adjust their size, just make sure they are smooth. they are usually a U shaped channel so look carefully at all 3 sides for dags etc...

Sometimes there are very slight dags that cause an axle to be held out of square, and this causes a once per revolution tightness that pulls the affected wheelset and adds a lope to the movement as the tightness comes and goes all at the same time.

Next most likely thing is quartering. All wheelsets should have the crank on opposing wheels with exactly the same offset - this is usually 90 degrees (but it can be just close as long as ALL are the same).... If one is slightly off, then it'll result in the same loping action as the dag on the wheel bearing channel.

you should beable to adjust by gingerly holding and twisting any offending wheel into line.

Those are the two most likely culprits.

While the drivers are out, by all means also check BTB but I don't think this will be the cause on a rolling road.....

Richard
 
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