07-17-2012, 08:00 PM
I'm not familiar with that loco, Leon, but the idler gear is usually the easiest one to replace. If the old gear was stripped of some or all of its teeth, it would be a good idea to go over all of the other gears (I'm guessing there's only the worm and an axle gear) to ensure that there are no remnants of those missing teeth remaining in places where they'll do more damage. This includes areas within the teeth of those gears, but also anywhere else where they might interfere with operation - bearings, electrical pick-up, or lead and trailing trucks.
In most cases, the worm and axle gear are formed from hard material (steel or brass), with the idler of a softer material - brass if the worm and axle gear are steel, or plastic if the other gears are brass (if there's only one gear between the worm and axle, it can be called either an idler gear or a worm gear). The theory behind using dissimilar materials in this manner is that the softer (and easier to replace) gear will be the one which fails if there's a problem.
One of the most common causes of gear damage is a mis-formed worm, especially at the ends of the tooth. You may want to ensure that the centre of the worm's thread is the portion which engages with the idler - this may require the relocation of the worm on its shaft.
Also watch closely to ensure that the tooth of the worm does not bottom-out in those of the idler and also that it's not merely skimming the top of the idler's teeth. This can be adjusted through shims placed strategically under the motor.
One you have everything properly installed, apply some plastic-compatible lubricant, finish re-assembly, and give 'er a test run.
Wayne
In most cases, the worm and axle gear are formed from hard material (steel or brass), with the idler of a softer material - brass if the worm and axle gear are steel, or plastic if the other gears are brass (if there's only one gear between the worm and axle, it can be called either an idler gear or a worm gear). The theory behind using dissimilar materials in this manner is that the softer (and easier to replace) gear will be the one which fails if there's a problem.
One of the most common causes of gear damage is a mis-formed worm, especially at the ends of the tooth. You may want to ensure that the centre of the worm's thread is the portion which engages with the idler - this may require the relocation of the worm on its shaft.
Also watch closely to ensure that the tooth of the worm does not bottom-out in those of the idler and also that it's not merely skimming the top of the idler's teeth. This can be adjusted through shims placed strategically under the motor.
One you have everything properly installed, apply some plastic-compatible lubricant, finish re-assembly, and give 'er a test run.
Wayne