02-17-2014, 05:25 PM
Your set-up on the loco looks good, with a nice straight line throughout the drive train.
Mostly just guessing here, Mark, but my first question concerns the scoring on the shaft. Do the grooves go around the shaft (like rings), or are they longitudinal? If the latter, they may have been caused when the worm was pressed onto the shaft - perhaps a burr in the bore of the worm. If you fitted the worm to the shaft, was the shaft clamped in a vise, with the jaws perhaps marring the surface of the shaft? That usually causes a minor displacement of material which causes a ridge and a groove - material displaced from the groove forming the ridge. That can be cleaned-up by chucking the shaft in an electric drill (don't allow the jaws of the chuck to damage the shaft, though)
then using a finely-cut file or emory cloth to remove the ridges as the shaft spins - the grooves shouldn't cause any problems. If the bearing is damaged, you should be able to get a replacement from NWSL.
Was it the gear case which was damaged by the heat? If so, it would likely have been where the bearing was seated, and in that case, you should probably replace the whole gearbox, as the alignment will likely be off. NWSL may provide replacement parts, as I've found them to be very accommodating, and especially so if the problem was caused on their end.
Another source of heat could be the thrust washers - while you don't want a lot of slop in the drivetrain, they can also be too tight, with the result that the bearings are attempting to rotate, perhaps intermittently, with the washers and the worm. You can thin a thrust washer by sliding it back and forth over a piece of fine sandpaper - only a couple of thousandths of play will be enough to prevent that scenario, but be sure to clean the washer before putting it back into the gearbox.
The only other issue I can see is the shaft protruding through the front of the gearbox - nothing wrong with it doing so unless there's a chance that it may strike something on the loco's frame or something else once the boiler is installed .
Wayne
Mostly just guessing here, Mark, but my first question concerns the scoring on the shaft. Do the grooves go around the shaft (like rings), or are they longitudinal? If the latter, they may have been caused when the worm was pressed onto the shaft - perhaps a burr in the bore of the worm. If you fitted the worm to the shaft, was the shaft clamped in a vise, with the jaws perhaps marring the surface of the shaft? That usually causes a minor displacement of material which causes a ridge and a groove - material displaced from the groove forming the ridge. That can be cleaned-up by chucking the shaft in an electric drill (don't allow the jaws of the chuck to damage the shaft, though)
then using a finely-cut file or emory cloth to remove the ridges as the shaft spins - the grooves shouldn't cause any problems. If the bearing is damaged, you should be able to get a replacement from NWSL.Was it the gear case which was damaged by the heat? If so, it would likely have been where the bearing was seated, and in that case, you should probably replace the whole gearbox, as the alignment will likely be off. NWSL may provide replacement parts, as I've found them to be very accommodating, and especially so if the problem was caused on their end.
Another source of heat could be the thrust washers - while you don't want a lot of slop in the drivetrain, they can also be too tight, with the result that the bearings are attempting to rotate, perhaps intermittently, with the washers and the worm. You can thin a thrust washer by sliding it back and forth over a piece of fine sandpaper - only a couple of thousandths of play will be enough to prevent that scenario, but be sure to clean the washer before putting it back into the gearbox.
The only other issue I can see is the shaft protruding through the front of the gearbox - nothing wrong with it doing so unless there's a chance that it may strike something on the loco's frame or something else once the boiler is installed .
Wayne