G & #1 SCALE
ARISTO CRAFT RS-3 DIESEL LOCOMOTIVE
This locomotive can be converted to Kadee® couplers using one of two methods:
OPTION 1: For 4 foot radius
We recommend carefully reading the entire instructions before you begin this conversion. Tools needed: Small phillips head screwdriver, tweezers, drill, 1/16" and 3/32" drill bits, Kadee® #238 or #239 gripper, small file.
This conversion requires the use of two packages. A #832 or #1832 is needed for the gear boxes and depending if the G scale or #1 scale size couplers are to be used you will need a #836 (G) or #1836 (#1) packet for the couplers. No alteration of the locomotive is required and it will negotiate 4 ft radius "S" curves.
Place the locomotive upside down on a padded surface and brace it so it won't roll over. Remove the small screw holding the straight centering spring (Kadee's gripper will help with the screw). Retain both the screw and spring for use with the new coupler. Remove the screw and washer which hold the coupler in place. By rocking the coupler, it can be pulled out over the post. Very carefully drill a 1/16" hole in the back of the #832/#1832 draft gear box as straight and level as possible .050" (just under 1/16") from the bottom and on the centerline 1/4" deep, just short of the boss (center pivot post) See Fig. 1. Drill the hole (for the retainer cap post) the rest of the way through the gear box shank, using a 3/32" drill bit. The retainer cap (lid) will be placed on the opposite side of the shank (See Fig. 1). Assemble the coupler according to its instructions, omitting the wire gearbox centering spring. Remove any burrs or flash from molding or drilling. Place the assembled coupler onto the coupler mounting post followed by the retainer cap and secure with the original screw and washer. Reinstall the straight centering spring and slip it into the 1/16" hole in the back of the draft gear box. Secure with its original screw (tweezers and grippers will assist here).
Note: If the 1/16" hole broke through the floor of the draft gear box, be sure to clean any burrs and check if the end of the straight spring interferes with the coupler. If so, trim off the appropriate amount from the spring, only enough to eliminate the interference.
Check for correct coupler height, function and clearance. If the centering action doesn't bring it back to center, remove the straight spring and adjust (carefully bend) as needed. Be sure the spring clears the screwhead on the top of the mounting post.
Drill a 1/16" hole .055" from bottom of gear box and on centerline
Drill retainer cap hole completely
through shank use a 3/32" drill
Rear view of gear box
Coupler mounting post
Aristo Craft spring
Retainer cap (lid) placed on the bottom of the shank
Original screw and washer
Option 2: #831 gearbox and a #836/#1836 coupler (G/#1 Scale).
For larger radius layouts of 4 foot or more and for closer coupling you can use the #836/#1836 coupler in a #831 draft gearbox. On 4 foot radius curves, the locomotive will operate in the coupled position but not in the delayed coupler position depending on what it is coupled with.
No alteration of the locomotive is required. The shank end of the #831 draft gearbox needs to be trimmed until you can fit the top of the mounting post into the large recessed hole of the gear box shank. Slide the box over the post until the shank touches the back wall of the coupler pocket area. Trim small amounts at a time off the end of the shank until it slips over the post (about 5/64"). Be careful not to remove too much at a time as it is important to keep a very snug fit where the post is against the back edge of the recessed hole and the trimmed end of the shank is against the back wall. After trimming the gear box shank, mark for the new mounting hole location. It should be 7/16" from the rear and on center. Use a 3/32" drill bit and drill a hole for the post's mounting screw. Note: this hole will not be centered in the large recessed hole. Assemble the coupler and draft gear box according to the instructions. The #836 G scale or #1836 #1 scale go into the #831 gear box. Slip the coupler over the post and secure with the original screw without the washer.
Check for correct coupler height, function, and clearance and make any adjustments necessary. If too high, loosen pivot arm screw slightly.