Assembly Report on BG-6-Kit

Click on the photos to see a larger version.

All parts of the “raw” kit

Early march 2001, I bought a Unicata kit of a “BG 6” drilling rig from Bauer, in order to convert a Liebherr-R-914-type excavator.
The provided assembly instructions were rather difficult to use, due to pictures in bad quality and wrong part-numbers, but this problem could be solved by studying the instructions intensively.
The packing of small parts into bags, according to their use in subassemblies also helped a lot. (See fig. 1). (Besides the overview, there are also close ups of the following subassemblies: guidance pole, support of pole, winches and the base model.)

A first inspection of the kit made clear, that a lot of refinement would be needed.
For example, the support of the guidance pole that is mounted on the carrier an in turn supports the guidance pole, was supplied in a hollow version. For a better look and for better stability, I decided to fill the support with small strips of plastic.
It was also difficult to glue the two parts of the support together, since all bearings had to be perfectly aligned.
Connecting the two parts of the guidance pole was trick too, since the upper part is of triangular shape. The edge of the table and a 30-cm-ruler served as an improvised alignment tool - combined with a good visual judgement.
Unfortunately, the related photo is rather blurred.
I used filler and sanded the pole as well as the support.

Before After
Subassemblies prior to … … and after painting.

After the subassemblies were sanded and prepared, all parts were to be painted.
With this, soon more problems began to arise: At first, I had bought primer and paint, “RAL 1004” in colour. (“RAL” codes are part of a standardized German colour definition system, mainly for industrial use.) Since these were rather viscous, and only a small airbrush was available as a painting tool, I had to thin down the primer and the paint. This made for a low opacity, so I had to apply about 5 layers of primer and paint each for a good result.
But after that, unfortunately a direct comparison showed, that the chosen yellow paint was way to light. So I bought a glass of genuine Liebherr paint at a local Liebherr shop. Since this varnish was rather difficult to use (e.g. only thinable with paint thinner instead of water), I had to sand and paint the parts many times over until an even, glossy surface was achieved.

After this, I could start with the final assembly. For this, I had to dismantle the R 914 according to the instructions of the kit. In order to be able to place the provided ballast (that prevents the rather heavy model from tipping over) in the upper carriage, I had to rework it extensively. It appears that the ballast is designed to fit into an older model (a R 912 for example).
After the ballast was fitted and the upper carriage partly re-assembled, the support of the guidance pole was installed on the base model and the assembly of the winches was completed.
Since I preferred the hydraulic rams from the R 914 to the ones supplied with the kit, I left them on the model an only “reinforced” them with small rods of brass that I placed in the them-

The completed model

I also replaced the supplied rivets with a selfmade version, made of hollow brass rods, cut to a length only slightly bigger than the thickness of the surrounding material. After putting them into the proper hole, I widened them a little with a pair of multigrip pliers. By the way: for cutting the brass rods, a mini drill fitted with a small cut-off wheel came in very handy.
Furthermore, the hydraulic ram that holds the rotary drive was replaced, since the ram that came with the kit, was made out of brass and had a skewed tapped thread. Instead of this, a new part of steel was used, that was lathed by a friendly model builder.
As a last refinement, I glued the hydraulic “pipework” from the base model to the support of the guidance pole.
After uncounted hours of work, the model is now finished in the middle of July.