HOn2½ Tractor Trailer Rail Truck

Next will be fabricating the front bolster. It's
going to be and all brass construction for weight.

I came across two shorter trailers I had. I figured these would
work fine. Wasn't pleased with the earlier longer vesion I was
going to use.

A better idea will be gained as to how I'm going to use the parts
in this picture. First I cut off the rear end axle of the truck.
There will be a brass frame added to hold the motor and drive
wheel. I've decided on one drive wheel on this do to complications
of adding a swiveling power truck. The front truck will be an N
scale truck, the drive truck will be bashed drive unit and the
truck under the trailer will be an N scale truck.

A belt drive to a single wheel axle will be used. The motor and gearbox will be one of the same motors I used to drive the Athearn crane boom and hook written up here.

In order to overcome the friction of the rubber band pulling
against the axle I'm using miniature bearings. They are 5mmM
outside diameter with a 2mm bore. I made up an axle to hold
the wheels on. I also had to make a bushing to take the 1.5mm
diameter shaft where the wheel press fits on so the axle could
carry the bearing. That's the brass part next to the bearing.

All the parts needed per side. From left to right: plastic hub
turned down from plastic truck wheel, brass bushing, 2 x 5
mm bearing, bearing case, truck side frame.

I made a crude fixture to hold the three parts together for soldering. It's at an angle so I can have a press fit to hold it
all together when I hit it with the iron.

I tack soldered a piece of brass the width of the wheels and temporally glued to the truck bed. The front truck is just placed under of the front to get a perspective of height. Now that I have an idea that this setup may work, I need to go back and make some final parts for permanent assembly.

I didn't like how the truck sat high in the back end. I think I've
finally come up with a frame under the truck I like and will work
with what I want to do. So I'm scrapping the plastic frame that
came with the truck as in the previous picture and substituted
a brass frame/floor. The back end is still to high even though it
looks like it's leaning backwards. I need to mill out the slots
deeper by about .032". If this works out the motor will be added
next and it'll be close for a test ride. Looks like a "rat rod" low rider right now.

The motor is the same that I used on my
crane project for moving the boom & hook.