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[Anonymous]

PLEASE HELP. I HAVE A COUPLE OF 12 WHEEL DRIVE LOCOS, ONE STAYES ON MY TRACK REALLY GOOD BUT THE OTHER JUMPS TRACK AT MY TURN OUTS .PLEASE HELP! [e-mail]

[Anonymous]

Firstly, what are the locos? A better description would probably help people to offer advice. On the basis of your description, I'd suggest you check the back to back gauge of the axles - the measurement from the back of one wheel to the back of the opposite wheel. Your local hobby store should be able to sell you a gauge to set this with, failing that, it should be 14.5mm - check it with a steel ruler. Assuming both locos are identical this is the most likely reason for the problem. I've had this problem with a few Athearn locos - Dash 9, AC4400, a few dummy locos. I had to do a little filing to sort out the powered locos - to allow the wheels to be set closer together. File a little off the axle gear where the stub axle plugs into it - make sure the brass bearings can turn freely and that you file the same amount off each end of the gear. If you don't feel confident about doing this (It took me a while to pluck up the courage to do it, and then more time to figure out the best method...), try asking in your local hobby store - they might be able to help you, some stores over here offer "loco doctor" services where you can bring in non-running locos for repair, don't know if these exist in the US as well? Hope this helps!

[nfmisso]

QUOTE: Originally posted by rickmartin

PLEASE HELP. I HAVE A COUPLE OF 12 WHEEL DRIVE LOCOS, ONE STAYES ON MY TRACK REALLY GOOD BUT THE OTHER JUMPS TRACK AT MY TURN OUTS .PLEASE HELP! [e-mail]

Rick;

First PLEASE STOP SHOUTING

And as RB said, you need to provide a great deal more information: scale, brand, models, turnout size, etc.

[dknelson]

Different makes have different tolerances, and different prototypes have different wheelbases and different rigid wheelbases, so the mix of manufacturer, model of locomotive, make of turnout and frog # all enter into play here. But as a rule, the larger the locomotive the larger the turnout, and larger the minimum radius, it will need
If you have Atlas Snap switches those are approximately # 3 1/2 frogs -- very small. Then many manufacturers have #4s, but many large engines need a #6 turnout.
Obviously if your layout is small you cannot simply replace #4s with #6s -- the lesson is that size of layout enters into selection of locomotive
The other option is that something is binding one or both trucks on the engine. The common Atheran metal strip that distributes current can sometimes get bent or inhibit normal turning of the truck. Run the engine, over and over, very slowly though the turnout while you watch. Is the front wheel lifting up? If so you may have a binding that might be addressed by taking the shell off and adjusting that metal strip.
I know how frustrating this can be --- good luck.
Dave Nelson