Saturday, 14 September 2024

Driving Truck to Open Wagon

The first wagon on the railway, the "interim" driving truck, worked fairly well but didn't look realistic. 

The "interim driving truck" in its original form.

Another problem was that the wood used to make the underframe had a slight twist which meant the whole underframe also had a twist, so that diagonally opposite corners were about 5 mm lower than the other corners.  When constructed, 3 mm packing was inserted at the bogie bearing points to compensate for the twist in the underframe so the wagon would track correctly and not derail.

One option was to build another steel underframe similar to the brake van and re-use the bogies, etc. to make a new open wagon.

In view of the still impending arrival of two open wagons from Mini Train Systems, it was decided to live with the existing underframe and make a new body loosely based on the WAGR GE open wagons.  Conveniently, there are a couple of GE's "preserved" (i.e. rotting away) near the old Denmark station site.

A visit to the local Mitre10 to investigate suitable plywood, resulted in the purchase of 290 x 19 mm pine boards which were a good size for the sides and ends, and easier to handle and cut compared to plywood.  The boards were flat and straight with no twist.

A V-shaped bit in the route quickly made grooves for simulated boards on the sides and ends.



The new wagon body quickly took shape with aluminium angles inside and outside to join the corners, sized to match the angle irons on the original GE wagons.  Packing under opposite corners ensured the body sat level, largely masking the inherent twist in the underframe.

The basic plywood seat can slide back and forth a bit to allow the wagon to be used in either direction.


A timely purchase of a new 3D printer allowed printing of larger parts including cosmetic ribs for the ends of the wagon, based on the dimensions of the prototype's pressed metal ribs.


The handrails and vacuum brake hoses are also 3D-printed.  Further work is still required to design and print ribs and simulated door details for the wagon sides.




 

Brake Modifications to the New Open Wagons

Both of the new open wagons include electrically-operated parking brakes on one bogie.  Parking brakes are essential as most of the track is...