1:32 Oberursel UI engine
Catalogue # D3208
Available from Story Models for £21.90
The Oberursel UI rotary engine was in fact almost a direct copy of the excellent and reliable French four-stroke Gnome-Monosoupape, which had already been employed by both the French and British aircraft designers to great effect, and remained, in various versions, in use throughout WW1 and beyond. The design itself didn't make the engine easy to maintain for ground crew who had to effect a disassembly of the cylinder heads in order to access the intake valve which could easily become jammed, or to adjust timing.
Visibly, the only real difference between the Gnome and the Oberursel UI engines was the location of the ignition spark plugs. Whilst the Gnome had its plus mounted at the top, left hand side of each cylinder jacket, the Oberursel had its plugs mounted to the ear. The Oberursel UI was used on the Fokker E.II/E.II 'Eindeckers', Fokker D.II and Pfalz E.II, E.III and E.VI types.
Taurus Models are a very new name on the WW1 aviation modelling scene, but one which have made quite an impact on those that like to detail their models aero engines to the max. In fact, apart from an ammo belt and shell set, this new company produces exclusively aero engines and upgrade components in both 1:48 and 1:32 scales. The subject of this review is the first 1:32 aero engine release from Taurus; the Oberursel UI rotary.
The Taurus Models Oberursel UI is packaged into a small box with a rather attractive satin finish thin card lid, with the finished and painted engine displayed on the top, and detail sections adorning the sides. It's obvious from the outset that this is going to be an upgrade aimed at the more serious and adventurous modeller. This EIGHTY part resin kit has a 'Simplification' symbol, neatly struck-through, so you are in no doubt that this upgrade will be one to challenge you.
Inside the box, three zip-lock bags containing the various dark grey resin parts, are supplemented by a single zip-lock which holds a length of very thin copper wire. A small instruction sheet is included.
The Oberursel has been practically stripped down into various major and non-major parts, but the breakdown of the engine does seem to be, in the most, very logical, and designed in this manner for a reason.
The first zip-lock bag contains the crankcase and airscrew shaft. The crankcase is simply one of the most beautiful and detailed resin parts I've seen. The various plates which are bolted to the crankcase body are cleanly-defined, and the hex bolt detail is extremely intricate and very sharp. Various orifices and indentations are included for pushrod linkages, ignition leads, and the cylinder placement holes are keyed so that the cylinder orientation will be correct. The rear of the crankcase exhibits the same high level of plate and bolt detail, plus the ignition lead insulator ring which then connects to the casting block. You'll need a razor saw to carefully remove this, but there is a narrow collar to give you some working room.
The airscrew shaft is a single piece item, with a small casting block to snip off. The part appears to have a correct slight taper too.
Our second zip-lock bag contains the nine cylinders, each connected to a small casting block, and with the cylinder orientation lug cleanly cast. The cooling fins are sharp and even all around the circumference, and the top of each cylinder has a cleanly cast hole into which the piston crown is to be placed. Those piston crowns are also to be found within this package. Each is cast to its own easily removable resin block, and again, the detail has to be seen to be believed. These parts are just a few millimetres in diameter, yet the armature linkage detail really is superb! They are also very fragile, so please handle even the bag of parts very carefully.
Our last packet of resin contains the rocker actuator rods, all cast onto a communal block, and protected with plates at the casting block ends which should hopefully prevent damage. Casting is superbly clean with no apparent finishing to undertake, with the exception of cleaning up the removal stub. Ten are included, so you have a spare!
Some of the most fragile parts, again ten off, are cast across two casting blocks. These are the valve rocker armatures. A micro drill bit or the end of a pin should be pushed through the holes on these to precisely clean them up, although not much work will be involved here. To remove from the block, I suggest cutting the block into sections and tackling each one with a razor saw....VERY CAREFULLY!
The actuator rod linkages and entry cups are also separate. These parts are so small, but precisely cast, and a test fit shows the linkages plug into the cups perfectly. These different parts are cast onto their own communal blocks and will need the lightest of cuts to snip them off. Again, spares are included.
Spark lines which insert into the insulating ring are supplied as separate parts, all neatly cast. If any of these tiny parts are lost, you could substitute with plastic rod of the correct diameter.
The last of the resin parts is a block containing the ignition plus, with plug into the indentation on each cylinder. Detail is just excellent.
Lastly, there is a little copper wire which is to be used for the ignition leads, and also for a little detail on the piston heads. Two diameters are supplied.
The instruction sheet is printed on a small, folded sheet of paper, with photographic illustration being in black and white. Some of these photos are quite dark, and you should use the photographs on the box lid to supplement your construction. Full colour instructions are available on the Taurus website too, and are accesible by clicking THIS link. These instructions show just how involved this mini-kit is. The valves can be positioned in either open or closed positions, and of course, there is a sequence to follow, neatly shown on the sheet. Some of the parts to the foot of the actuator rods will need a little snipping to alter their length so that you can pose the rods and valves properly. This aspect looks fairly easy to follow.
All parts are identified easily on the instructions, and there is a suggested stage whereby Taurus indicate that you should perhaps paint the construction. Simple mention of paint colour is given, but I really would have liked to have seen how the modeller who made the box illustration model actually finished his with oils etc.
Er, wow! Yes, this is a very complicated model kit to assemble, requiring visual and mental dexterity, but the results are nothing short of astounding. Who would have thought you could have broken down a rotary engine into 80 individual parts!? Well, now, seeing is believing. This kit is very much a project in its own right, and it almost seems sacrilege to mostly cover it up within a cowl. Whether you decide to do this, or build a trestle display for it, the end result will be spectacular.
Very highly recommended.
My sincere thanks to Story Models for the review sample. To purchase directly, click THIS link.