Weinert’s original coupler, while it is not exactly to scale, is the best available option for supering German H0 model trains with a prototypical buffer and chain coupler. The following steps outline how I assemble and optimize the coupler to allow for safe and reliable operation.
Required tools and materials
- Weinert 8632 original coupler kit
- 0.5 mm drill
- 0.7 mm drill
- 0.8 mm drill
- miniature reamer
- jewelers saw
- fine sand paper
- jewelers flat nose pliers
- Blacken-It (or similar bluing solution)
- needle tip precision lubricator
Preparing the parts
Start by cutting the parts from the casting tree using a jewelers saw and smoothen out any leftover kinks using fine sandpaper. I found that sandpaper works better than a file because it is flexible, but be careful not to apply too much pressure when sanding as the material is fairly soft.
Next, widen the holes of the two lugs with a 0.5 mm drill and the ones on each end of the releasing screw using a 0.7 mm drill.
After completing these steps, widen the area behind the towing hook with a miniature reamer. Take enough material away so that a 0.8 mm drill goes through the opening without any problems. This ensures that the shackle can easily fall into it.
Finally, widen the hole behind the towing hook with a 0.7 mm drill.
Assembling the coupler
Take one lug and fit into the the hole behind the towing hook. Then take the other lug and fit it into one of the holes in the releasing screw. If the lugs don’t fit in either of the openings, carefully widen them with a miniature reamer until they fit. The holes need to be wide enough so that the lugs can turn in them freely. Do a gravity test by holding the towing hook and releasing screw at various angles. If the the lugs still get stuck, widen the holes some more.
Next, connect the two lugs. Do the gravity test again. If the parts are moving freely finish this step by pinching together the ends of the pegs with a pair of jewelers flat nose pliers. This will prevent the lugs from falling apart.
As the last step, connect the shackle link with the releasing screw. Again, make sure the hole in the releasing screw is wide enough. Do the gravity test, correct any issues and the coupler is fully assembled.
Putting on the finishing touches
The kit comes blued out of the box, but during assembly bare metal spots may appear on the coupler. To give it back its weathered look, clean the coupler with your favorite solvent and use Blacken-It to blue it. Make sure there are no bubbles attached to the metal for an even look.
When the bluing process is done, remove the coupler from the solution and let it dry. Finish the job by applying a tiny amount of oil with a needle tip precision lubricator.