Back in the 50's, this was offered for $5, with a 10.5 k RPM, side magnet, open-frame motor, 13:1 gear ratio and 37" drivers, producing about 89 SMPH. Desiring to use this as an industrial switcher, slowing was indicated. Applying a Jameco 231731CA motor at about 5 k RPM would yield about 42 SMPH and a lower current for those who desire it. Still a little fast for an industrial complex. Regearing with NWSL 24:1 worm and wheel would lower it to a more acceptable top speed of about 23 SMPH.
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Original motor visible ih cab.
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New motor mounted.
The original motor was tilted with a mounting bracket. The slot in it was too small to accept the new motor bell and had to be widened. In preparation the short end of the motor shaft was ground flush with the bell and terminals were bent down to insulator level. Trial testing the new motor fit well, but the mount holes were obscured by the space between the two adjacent slots on either side. This required removal. The resulting hole was too large for the screw heads and thus required washers.
Since the new motor shaft was a little short and the NWSL worm fit loosely; for a more secure mount, a NWSL 2 mm to 3/32" bushing, partially filled with a short length of shaft rod was pressed part way into a 3/32" bore worm. This assembly was then pressed on motor shaft.
After determining correct polarity one terminal was soldered to the can rim and the pickup lead was soldered to the other.
To remove the geared driver, spread the frame rail with a screw drive to free the axle end from the journal. Since the drivers are fastened to the axle with nuts, the gear change is easy. Screw off nut and finger pull wheel. Pull gear. Press on new gear. Place wheel on axle and secure with nut. The frame is riveted at the ends, and is subject to skewing during work. If wheels do not sit levelly on track, light finger twisting can correct this.
The total weight was just under 3 oz = 80 gm , so lead weight was added in the hood area.
