MDC devised this ingenious mount for their new loco kits in the 70's. The top mounting was apparently designed for proper worm mesh with the parts used. But the lower mounting permitted an adjustable mesh on the lower spur gears by sliding the whole unit back and forth. This allowed its use on various frames with different axle center to mounting base hights.
The 22 tooth worm gear and 11 tooth pinion gear were one casting which turned freely on the shaft pressed into holes in the forked mount. The driver had a 33 tooth gear to yield a 66:1 ratio. Careful mesh adjustment was mandatory to avoid stripping the pinion.
Note: Adjust brightness and contrast for optimum viewing.
Side and top view showing shaft partly pressed into tight hole to prevent loss
Side view of mount on loco showing the gear axis angle offset from vertical.
Top view showing offset widening of frame gear slot and fork.
BACK TO BOWSER PRR A-5
BACK TO REPOWER EXAMPLES
