Rayin"S" posted:Chuck,
I was wondering about this very thing, I have locomotives with three different axle brgs and there is quite a difference in the gear boxes. Might it be that the worms have to be ordered by the type of brgs on the axle?
Ray
A bushing won't change a gear to worm relationship unless a bushings I.D. is offset from the o.d.. Even customizing with a lager/smaller axle, all holes reference the same center point. Resize a gears axle hole? Same center point so the o.d. is still at the same height.
It would more likely be the gear offset left or right from ideal. A machinist's method to check would be blue the gears , run the gears, and the contacting surfaces will have the blue worn off. A clean line up the middle means your good. Off to one side, move the gear accordingly.
Checking the worm & shaft is 90° to the gear teeth is also important (gear axle is easier to use, parallel to the gear teeth if correct (though an angle of a beveled gear would have the worm shaft at 90° to that angle) The contact on the worm is similar, but the adjustment not as critical and just fore and aft along the worm shaft. The seating depth shouldn't have pressure, but either no play or a very slight play. Brass gears however are often in need of running and breaking in because they ARE installed under a slight pressure to help with a break in of the easy to wear brass, achieving the very minimal play possible in a short time.
The type of worm&gear is also important. Even with the right tooth count and o.d.s, tooth face type must be matched right, to mesh right. e.g. some gears are not beveled, but the teeth are at an angle to the axle while others are parallel to the axle. Though each worm may seem identical at first glance, they are not the same.
