Bachmann On30 house cars are the right size for 55n3. They match the early cars from the Pacific Coast Railway. We will be lowering them to have a coupler center height of two feet.
Our lowered car behind Bachmann's 55n3 4-4-0
Clip apart the Bachmann frame.
The frame has to be relieved at the lug arrow to clear the truck bolster lug.
The old frames with the high bolster have to be cut back 1-1/2" to allow the trucks to swing. The newer cars have this frame member moved outboard.
A new bolster is made from 1/8x1/4 material. Drill a 11/64 hole to clear the floor lug.
Cut Grooves into the bolster to clear the truss rods.
Glue truss rods into the queenposts, make sure the turnbuckles are vertical.
The bolster needs clearance pockets to clear the lugs on the truss rods.
The coupler mounting pad needs to be relieved to clear the jump-up in the car.
The width is determined by the coupler mounting box.
File the buffer block even with the coupler mounting pad.
Slice off the truck lug from the old bolster. It has a taper so has to be mounted with the old end down. Glue it to the new bolster.
I use Accurail Proto:HO couplers. They are the right size to represent 3/4MCB couplers. They are the best looking and functioning coupler.
The "scale" Kadee and McHenry also represent that size. The "HO" couplers represent a full-size MCB coupler in Scale 55.
Couplers mounted at this height will still function with the On30 couplers on Bachmann cars. No need for a massive changeover. They can be converted at leisure.
Our finished car with an unpainted Scale 55 figure.