build review 1:25 Rolls Royce Trent-900 Turbofan - SKYMECH - via EngineDIY (Build Review)

[James H]

1:25 Rolls Royce Trent-900 Turbofan - SKYMECH - via EngineDIY
Available from EngineDIY for $99.99

 

 

The Rolls-Royce Trent 900 is a high-bypass turbofan produced by Rolls-Royce plc to power the Airbus A380, competing with the Engine Alliance GP7000. Initially proposed for the Boeing 747-500/600X in July 1996, this first application was later abandoned but it was offered for the A3XX, launched as the A380 in December 2000. It first ran on 18 March 2003, made its maiden flight on 17 May 2004 on an A340 testbed, and was certified by the EASA on 29 October 2004. Producing up to 374 kN (84,000 lbf), the Trent 900 has the three shaft architecture of the Rolls-Royce Trent family with a 2.95 m (116 in) fan. It has a 8.5–8.7:1 bypass ratio and a 37–39:1 overall pressure ratio.

 

 

The Trent 900 is an axial flow, high bypass turbofan with the three coaxial shafts of the Rolls-Royce Trent family. The 2.95 m (116 in) fan with swept blades is driven by a 5-stage LP turbine, the 8-stage IP compressor and the 6-stage HP compressor are both powered by a single stage turbine, with the HP spool rotating in the opposite direction of the others. It has a single annular combustor and is controlled by an Electronic Engine Controller. 

Abridged from Wikipedia

 

The kit

This is certainly the most inexpensive of the turbofan kits I've looked at here, but the first indicator of reason is the weight of the box. It's very light indeed. This kit is mostly made from 3D-printed parts, made with some very strong, metallic resins. Some sections are also pre-built. The kit is packed into an attractive and glossy black box, with a single line drawing image of the Rolls Royce Trent-900 on the side. The bus is opened via a top lifting flap. Inside the box are two trays of parts. 

 

This tray contains the main forward ring and fan (under the white styrene protector), and two pre-assembled units. These are the tail cone with its electronics, and also the display stand with more electronics.

 

 

This tray has only pre-assembled unit; namely the main body which is made in a copper coloured material, with internal stators in a brass colour. Other parts here are various compressor blade rings, spinner, turbine shafts, bearings, screws, and the only tool you will need...namely a small screwdriver.

 

 

Work begins by taking the six blade rings for the high pressure turbine. The first five simply slide and click onto the turbine shaft, in order of decreasing size. Arrows on all parts indicate the orientation of the parts, and the fit is incredibly accurate and positive. The last ring fits at the foot of the shaft as seen in the final image. A bearing is then pushed into each side of the turbine shaft, to complete this assembly.

 

 

 

The next assembly is the low pressure turbine. This assembles in exactly the same way as the previous unit...arrows are used to align the turbines to the shaft. This time there are only four to fit, with two of these being identical. 

 

 

It's now the turn of the main impeller to be fitted to the drive shaft. Self-tapping screws are used to fit this. As a precaution, I only used absolute minimum of torque to screw the parts together, but that was probably just me as the parts are very robust. The spinner is then pushed into place. This is printed in two colours to create the spiral, which is a safety feature of the real engine.

 

 

 

The main fan blade housing has a cutaway section so the modeller will be able to see the interior parts rotating. This is simply fitted with a bearing.

 

 

 

The main engine body is an extremely attractive single-piece unit, as I mentioned earlier. We now take this and also push together both the high and low pressure turbine units. 

 

 

 

 

 

 

The fan unit actually fits quite easily into the engine body. There is some flex in the materials and a small push allows the fan to be quickly inserted without any fuss.

 

 

 

The tail cone is called the 'power module' in this kit. That is because it holds the drive motor and all of the electronics associated with rotating the engine. This and the main fan unit fit together by means of a keyed slot in the shaft. More self-tapping screws are now used to assemble both parts. 

 

 

The main fan housing unit is now screwed to the turbofan body. The fan assembly then simply pushes into the engine to lock it in place.

 

 

There's no connecting wires between the engine and the base. Instead, two copper contacts on the power module, are used to transfer voltage from the base to the engine. These sit together with some positivity, and the engine can then be powered. When the lever is first moved, it will click, and the red LEDs at the tail, will light. Push further and the engine begins to rotate. The speed can be controlled depending on how far you push or pull the lever. Operation is fairly quiet too, and unlike the other engines, this one doesn't have the pre-recorded jet engine sound. It isn't missed or needed though. You can see the fan in operation in the bottom photo. 

 

 

OPERATIONAL VIDEO

 

 

 

Conclusion

This little kit took less than an hour to build, and was actually a very satisfying little project and highly enjoyable. Being 3D printed was no detriment to the fun and final appearance of the completed model, and of course, those materials help to create a relatively cheap way of building your own little turbofan engine for your office desk. The kit itself is high quality and fits like a dream. The only thing I'd do myself would be to make a Rolls Royce display plate to cover the manufacturer name on the base. 

 

My sincere thanks to the folks at EngineDIY for sending out this great little kit for the purposes of review here at Model Ship World. To buy directly, click the link at the top of this article.