Timberkits Oilfield Derrick
The Oilfield Derrick is a big model with big beefy parts. On the other hand the mechanism is rather simplistic and assembly is pretty easy.
Finished model.
Finished model.
View from the top of the tower.
The Oilfield Derrick measures nearly 16" tall and "towers" over other Timberkits models. Here's the Drummer for comparison.
Did I mention this kit is big? Instead of the usual vacuum-formed parts trays you get a big honkin' box o' lumber.
Box and lumber.
The instructions for this kit feature color photographs as opposed to the usual exploded line drawings. This is also the first kit I've encountered that's built from more than just wood. There are a couple of nylon spacers and a black rubber drive belt.
Instructions.
Before attempting to glue the subassemblies to the base I set up an experiment on the workbench to determine exactly how far the pump house should be positioned from the transfer pulley block. The black rubber drive belt is pretty stiff. There is little margin of error between too much tension and too little. In my case 1.5" seemed about right.
The pump house is 1.5" from the transfer pulley block for proper belt tension.
The model is built on a thin plywood base that is rather flimsy. My base already had a slight warp to it right out of the box. I was convinced that the warp would only become worse under tension of the drive belt. Fortunately the kit includes a leftover piece of wood called the "brace spacer" that was used earlier during construction of the tower. I shortened and narrowed the brace spacer into a custom brace that fits between the front roof truss of the pump house and the transfer pulley block. The spacer will absorb stress from the drive belt and stiffen the base between the pump house and the transfer pulley block.
Custom brace between the front roof truss and the transfer pulley block.
The lower pump arm must be removable from the transfer pulley in case the drive belt ever needs to be replaced. Therefore I only applied a tiny dab of glue to the bottom retaining pin. I should be able to break it loose if I need to. Another alternative would be to replace the belt with a spring-type belt such as those found on tinplate model steam engines (Mamod engines, for example). These springs can be cut to length and then the ends are screwed into each other to form a belt.
Just a tiny dab of glue on the bottom retaining pin.
I chose not to glue the roof to the pump house. I did use the pump house as a form when gluing the two halves of the roof together.
Removable roof.
Update: I still wasn't happy with the rigidity of the plywood base so I formed a sub-frame using some ¾" pine stock I hand on hand. The pine was a good color match. I should have taken the time to miter the corners. But now the base has the same sturdy beefy feel as the rest of the model.
The rear side of the sub-frame is clamed in place as the glue dries.
Finished sub-frame.