T-700 Turboshaft Engine - Teching - via EngineDIY (Build Review)

[James H]

T-700 Turboshaft Engine - Teching
EngineDIY
Available from EngineDIY for $499.99USD

 

 

 

The General Electric T700 family are turboshaft and turboprop engines in the 1,500–3,000 shp (1,100–2,200 kW) class. The T700 was initially bench-tested in 1973, passed military qualification in 1976, and went into production in 1978. The initial "T700-GE-700" is an un-geared free-turbine turboshaft, with a five-stage axial / one-stage centrifugal mixed-flow compressor, featuring one-piece "blisk" axial stages, with the inlet guide vanes and first two stator stages variable; an annular combustion chamber with central fuel injection to improve combustion and reduce smoke; a two-stage compressor turbine; and a two-stage free power turbine with tip-shrouded blades. The engine is designed for high reliability, featuring an inlet particle separator designed to spin out dirt, sand, and dust. The T700-GE-700 is rated at 1,622 shp (1,210 kW) intermediate power.

 

 

The T700-GE-700 was followed by improved and uprated Army engine variants for the UH-60 Black Hawk and the AH-64 Apache helicopters, as well as marinized naval engine variants for the SH-60 Seahawk derivative of the Black Hawk, the SH-2G Seasprite, and the Bell AH-1W Supercobra. T700s are also used on Italian and commercial variants of the Agusta-Westland EH101/AW101 helicopter, and Italian variants of the NHIndustries NH90 helicopter. These are all twin-engine machines, except for the three-engined EH101.

Abridged from Wikipedia

 

The kit 

This kit is beautifully presented in a tough box with numerous images of the finished engine. This one is rated at 4 star with regard to complexity, and contains around 470 parts, inclusive of the various bolts, nuts and washers. Not quite sure how the star rating works, but this one was very straightforward to build, so all is good! Under the lid, the first thing you see is a nice, full colour, 88 page manual, with every stage presented in colour CAD format and easy to understand text. A full colour parts index is also included, although that's more for checking individual parts, which the main instructions do very well anyway. The parts trays are protected under a thin sheet of clear acrylic.

 

 

Three parts trays are included, in semi-rigid foam, holding the parts securely in place. The first try shown underneath, also has two containers which contain all of the screws, bearings, specialised fittings, nuts, etc. The parts are clearly identified from a list in each lid.

 

Building the base

As with many of these aero engines, the T-700 requires a base unit from where it will be controlled. Unlike the others though, the modeller gets to build this one from components. Here you see the cast shell, control board, dual lithium batteries, the speed controller and also the various port connections. Also seen here are some tools supplied to start work on this kit.

 

 

The base unit is very straightforward and it's seems very unlikely that anyone could go wrong with this assembly. When the components are fitted, a small plate holds everything in situ.

 

 

Engine construction

From here, I'll merely show the various assemblies being constructed, and you can follow along. Where appropriate, I've used lithium grease for things like gears. The bearings don't need any lubricant.

 

 

[James H]

[James H]

 

 

 

Conclusion
Out of all the engines I've built so far, this is by far one of the easiest in terms of design and accessibility for the various fasteners that inevitably go into awkward places. I do think I'd have liked the LEDs to have been a little brighter, but they do show up well in subdued light. If helicopters are your thing, then this is most definitely one to add to the collection, especially anyone who liked the Black Hawk. Great kit, easy assembly, and very rewarding. 

 

My sincere thanks to EngineDIY for the sample you see here on MSW. To buy direct, click the link at the top of the article.

 

 

 

[James H]

Video coming very soon.