Since top speed at 12 V is too fast to take a 36" radius curve with 24" easement, this is a perfect candidate for re-powering . The method used does not interfere with coupler box movement or wire spring. Converting a dummy unit is far less expensive.
Remove the body shell. Before removing trucks, measure floor hight and power truck center for later reference. Disassemble and remove trucks, shafts, couplers and motor, down to a bare frame. Cut off shaft support post, at none powered end, to floor level.
At the powered end, use a machinist's square to scribe a line across the frame floor, even with the center side of the square rubber band hole. Next, with calipers, scribe a line .2" in from each side of frame from transverse line to coupler notches. Remove floor inside lines. For reference, mark center lines on floor with fine marker or scriber. >
Note: Adjust brightness and contrast for optimum viewing.
Hole cut in floor. Fork screw just visible on left edge.
After eye-balling , shimming the SPUD ZEE bracket to floor bottom was the best choice. On the bottom, locate hole half way between box and edge of opening just cut and on the longitudinal center line. Drill and tap for 2-56 screw. Cut ZEE bracket about .03" short of the box to edge distance to provide fork for adjustment. Mount dummy truck and SPUD with bracket, shimming with washers to correct hight. center SPUD and track test.
Fork, shim washers and screw mounted on ledge.
Prepare the side-frames by removing the bolster extensions flush with back of frame. Smooth carefully for ACC gluing to mounting bracket.
Unscrew SPUD and carefully remove bottom coverplate to mount side-frame bracket. Use dummy truck as guide in selection. The SPUD WB-31 wheelbase is about 1.25 mm (4.2 scale inches) longer than the side-frame 's, but the axles fit in holes. The difference is not objectionably noticeable, except to the purist nit-picker.
Caveat: When gluing,
ensure the axles do not touch side-frames , else there could be a dead
short.
Truck showing wheel base differences.
Full view showing hardly noticeable, wheel base differences on left truck.
Unobstructed view of rear windows can just be seen.
Adding dummy pickup is easy, since one side-frame is grounded to mainframe and the other has an insulated screw for a lug, ala unmodified motor wiring. If desired, weight can be hidden in the two box and vacated motor cavities. Track test and then finish it. Unit can pull two properly lubricated dummies easily on moderate grades at speeds in the 80 smiles/hour range.
