Installing Hook & Loop
Couplers
on the
SD45, RS3, Center Cab and Lil' Critter
By Ron Wenger
Ever since the introduction of Large Scale trains in the 1960’s some of you have had a love affair with the hook & loop coupler. I have used them, but like Many Large Scaler's I prefer the knuckle coupler. When I was asked to take a look at this problem I approached it with the idea that there is no reason the hook & loop coupler cannot work on the newer diesels.
Previously with the U25B and the FA units and the three Aristo Craft steam locomotives hook & loop couplers were not a problem, you just switched couplers. This is not true for the RS-3, Lil' Critter, Center Cab and new SD45. For the Hook and Loop user you either did minor surgery and defaced or sacrificed some detail on your model locomotive or ended up using a transition car.
After taking a serious look at the problem I have come up with a couple of solutions.
|
In the first solution cut away
the locomotive parts indicated in white in the photos to the left.
This will allow you to mount the couplers using the coupler mounts
on the locomotive for the standard couplers.
This does two things. One;
it requires you to fit the couplers where they were not designed to go,
bringing the couplers a little too close to the body to actually work
properly. Two; it cuts back
on resale value if you decide to move on to another road name or new
diesels.
After some thought and experimentation I came up with a simple solution to the conversion problem. The solution will use the existing mounts and part of the knuckle coupler. The solution is to remove the knuckle and insert the hook and loop coupler into the coupler mounting bracket. There are two ways you can do this. The first puts the coupler closer to the locomotive and requires a little more work. The second puts the coupler about one quarter of an inch further from the locomotive. Both solutions take less time to do than it takes to read this article. |
Step 1
The first thing you have to do is remove the complete coupler from your SD45, RS3, Lil' Critter or Center Cab. Save the centering wire and all screws. Remove the two screws (one screw on the SD45 coupler) from the top of the coupler mounting bracket and carefully remove the knuckle. Set the coupler mounting bracket and cover aside. Make sure you do not loose (launch) the little coiled spring and plastic centering index.
| Step 2 (Version 1)
Enlarge the front (inside) mounting hole of hook and loop coupler. Drill out the hole using an 11/64ths drill bit. Make the front (inside) mounting hole on the coupler shank large enough that the bit is loose. You don’t need a drill press for this just a steady hand. I drilled mine out and used a small file to dress the hole. Now cut the back ¼ inch off the coupler shank. This cut is just about in front of the mounting hole closest to the back of the coupler. Next remove just a little over ¼ inch of the tab on the bottom of the coupler. You also have to remove a about ¼ of an inch off the two small spines on the top of the coupler shank. The spines are guides for mounting the couplers on other models. They have to be cut off past the enlarged mounting hole. This will allow the hook and loop coupler to be inserted into the coupler mounting bracket that the knuckle coupler was in. Step 2 (Version 2) Enlarge the rear (outside) mounting hole of the hook & loop coupler. Drill out the hole using an 11/64ths drill bit. Make the mounting hole in the back (rear) of the coupler shank large enough that the bit is loose. Be careful, this hole is close to the end of the shank. Be sure to leave plastic between the mounting hole and the end of the coupler shank. You also have to remove a about ¼ of an inch off the two small spines on the top of the coupler shank. The spines are guides for mounting the couplers on other models. They have to be cut off past the enlarged mounting hole. This will allow the hook and loop coupler to be inserted into the coupler mounting bracket that the knuckle coupler was in. |
 Aristo-Craft Couplers & Modifications  Hook & Loop Coupler and modified Hook & Loop Coupler with Knuckle Coupler Shank |
Step 3
Position the hook and loop coupler into place where the knuckle was on the coupler mounting bracket and reinstall the two screws (one screw on the SD45 coupler).
Step 4
Reinstall the coupler on the locomotive.
Coupler Placement on RS-3/Lil' Critter or
Center Cab Switcher
  SD-45 Coupler Placement Using Front (Inside) Mounting Hole |
  SD-45 Coupler Placement Using Rear (Outside) Mounting Hole |
Step 5
Go have fun
I know that there are a few of you who are going to think that these stick out a little too far. But if you get in any closer you are going to create other problems. You have to admit, the hook & loops look a little out of place on most rolling stock. They are a trade off for the knuckle couplers. What I have attempted to do is give you a couple of options for this problem. I tried these on my railroad and ran my samples for several hours with no problems being encountered.
Ron
