The couplings supplied by Heljan on their coaches are the screw link type. The sort that try my patience when trying to couple up a train; especially when doing 10 coaches. In view of this I decided to convert them all to Kadee’s. For those not in the know these are Buck-Eye type
couplings. They are not 100% authentic, although the Blue/Grey MkI coaches I’m fitting them to did have Buck-Eye couplings as well as screw link.
The type I’ve fitted are Kadee No.746. Initially I did 2 coaches first and ran them on the Test Track; in both directions i.e. being “Pulled” and “Propelled” , and at maximum speed. They ran perfectly.
The screw link couplings fitted by Heljan are secured to the coach chassis NOT the bogie. I have attached my Kadee’s to the bogies. Again not 100% authentic to do it this way, but the advantage is they are articulated and save a large amount of “butchery” that would have been required to the coach chassis. I secured the Kadee coupling to the bogie via a homemade aluminium plate.
The Kadee coupling is fitted WITHOUT its gearbox. I found no problem with this as the coupling gains its lateral movement by being bolted to the swivelling bogie.
Obviously the first job is to remove the bogie from the coach. Next a small 3mm diameter hole is drilled in the bogie to take the plate fixing bolt. Additionally a small part of the bogie is cut away to take the plate and the Kadee.
Into the 3mm hole is inserted a M3 bolt. Because the bolt and its hole are the same diameter some pressure is required to start threading the bolt into the hole. Once the bolt is through the bogie, bolt on the aluminium plate. The 4mm distance between the edge of the plate and a hole goes on the inside of the bogie.
Next you need to file off the small tag at the rear of the Kadee. In this picture, you can see that the lower Kadee still has its tag and in the upper view this has been removed. This allows the Kadee to sit back snuggly in the recess cut in the bogie.
Finally fit the Kadee coupling to the upper side of the plate. The washer between the coupling and the plate—DO NOT FIT– this is not needed. What will need to be done is to insert a M6 washer between the bogie and the coach where it pivots. The overall washer diameter must not exceed 30mm. You can get the ideal washer from Wilko. These are approx. 1mm thick. The reason for this washer is that I found some of the flanges rubbed on the underside of the coach floor.