Assembly report on the R 914 with long reach boom
Click on the photos to see a larger version.
|All parts of the “raw” kit|
Some time ago (to be precise, in April 2002, at the Modelshow Europe), I bought a MEC kit that allows the replacement of the standard gooseneck boom of a Liebherr R 914 with a long reach boom.
All large parts in the the kit are made from resin. These are supplemented by a few smaller diecast parts as well as aluminium and brass tubes and thin black wire to make the pipework from.
Additionally, the kit comes with a letter-sized assembly instructions sheet. This might seem a little thin, but contains nonetheless all necessary information.
Of course, the assembly requires some refinement to be done on the parts (like on other kits too), but only rather few. Nonetheless, the resin requires a little rethinking, in case one (like me) has mainly worked with metal lately. (On the other hand, this can be an easy entry into the world of 1 : 50, if you change from plastic kits, e.g. 1 : 87.)
For example, you shouldn’t use coachwork filler, since this becomes harder then the resin when drying. So the subsequent sanding would mostly take away the resin and not the filler. You should use special plastic filler instead, which can be obtained in toy stores with a model making department. But unfortunately, the Revell filler I use was rather unpleasant zu work with since it is a lot more stringy than the coachwork filler.
|Joint between boom and stick|
The assembly itself went without bigger problems. This also requires the hydraulic rams and cylinders. To do this, the aluminium and brass rods are cut to length. Then one diecast end piece ist glued to each tube. (The supplied tubes are rather short so you’ll have to be carefull not to waste an inch of them.)
Unfortunately, the two man resin parts had view blemishes from bad casting which I could mend with the help of a little steel wire and small brass tubes. This photo shows an example of this: The rightmost “hydraulic connector” was repaired in this way. (Shown after painting and assembly.)
|All parts after painting|
After all parts were smoothed sufficiently, they were painted in the proper colour and assembled afterwards. For this, MEC uses non-hollow brass rods that allow very small diameters – contrary to screws or hollow rivets. (For example, 3/64″ (0.8 mm) at the linkage between boom and stick.) Thanks to the resin, drillings can be made a little tight so the brass rods will be kept in place by friction only. Only two rods at the linkage of the bucket and the main joint between boom and stick require a little more fixing. This can be done with the help of a small drop of PVA glue like recommended by MEC.
I only had to use the well known “do-it-yourself rivets” at the joint between boom and base model, since the Liebherr model inevitably had 1.5-mm-bores (~1/16″) at that bearing.
|Close-up of the bucket|
|Mounting of the main cylinders|
Additionally, I put two decals, reading “914 Litronic”, that I had custom made by Frank Adam, on the model. (You should do this prior to final assembly.)
Finally, I added the hydraulic pipework. For this I used super-glue, which has a very low viscosity and thus flows well even in the very small bores. Unfortunately, MEC didn’t supply enough wire with the kit, so I also had to use cut sealings from watches.
Aside from this, you can get a finely detailed out this kit which is partly due to the hydraulic cylinders that allow the full pipework.
But unfortunately, these cylinders also are a weak point of the model. Despite the fact that I had widened the aluminium tubes at the lower end in order to get greater friction, the the cylinders aren’t able to support the boom at random positions. This is an especially sad thing, since the lightweight resin would have allowed even great reaches without the model tipping over.
There’s one more thing to say about the main cylinders supporing the boom: Since there is no pipework planned around these cylinders, one could, in theory, re-use the cylinders supplied with the base model. But in reallity, this won’t work because of the fact, that the base model’s cylinders are mounted to close to the boom, which would made them rub against the boom at once. So the cylinders supplied with the kit are build in a way that they are slightly shifted to the outside. (See this picture.)
My conclusion: You can build a great model from this kit of a machine, that is rather rare both as model and as a real machine. Unfortunately, the kit does have some smaller weaknesses and leaves room for personal improvements respectively
|Vorbild und fertiges Modell|