Final Assembly -Base Mount


Throughout the serialization of this project, you have seen glimpses of the unusual mounting system I chose. It was engineered "on the fly", with no plans drawn, and parts packed in fairly tightly, with an eye on maintainability and functionality. As much as possible was made modular, to ease removal of critical subassemblies without disturbing the neighboring components. Here, it is all brought together in sequence.

  The basic structure of the rails consists of 2 aluminum angles conected by .032" sheet aluminum. The slots seen in the sheet are access slots so that a small box wrench may be snuck inside to tighten connections with the turboprop in place.
The ECU case goes on next. Outputs for the ECU are all oriented towards the front of the turboprop. Sensor input ports are located on the right side of the blue ECU case in this picture. The Fuel Manifold is mounted as well, the cross-member at the bottom of the picture.
The ECU board is next, connected to the power cable and switch, which is seen lower left.
Here is the gearbox oil pump "pack" ready to install. It is secured with thumb nuts on the leftmost rail, with the aluminum angle both securing the pack and acting as a heat shield to some extent.

The oil pump is in position.

Next, on the right rail, is the fuel pump. It is mounted in a fashion similar to the oil pump pack. The flexible tube here is the only flex tubing within the turboprop, and was used to make installation easier, as well as provide visual cues to fuel flow. It also allows the use of stock R/C filters.

A right-side view of the fuel pump being installed. It's getting a bit tight down there! Before the fuel pump is installed, the sensors are pre-plugged into the ECU, as access to these ports is impossible with the fuel pump in place. ECU sensor input includes two carry-throughs (from the fuel manifold) for R/C and ECU data readout, along with a tach and EGT sensor.

At the forward edge of the ECU case are the electrically noisy output ports for gas solenoid, fuel pump, and glow plug, as well as cables for the battery input and starter motor connections. Since these were perilously close to the power turbine NGV area, I engineered another heat shield, which protects the cabling from heat. I labeled these areas appropriately. Note the neat installation... yes there are cables behind the heat shield. The propeller end of the turboprop is to the upper left in this picture.

Rear View (Gas Gen end):

With all of the ECU wiring complete, this is what the base looks like. The glow-plug cable is the red one to the left. The aluminum cylinder at 4:00 is a potted 2SS52M magnetoresistive sensor for gas gennie tachometry. An Omega EGT probe is located just above the tach.

Front View (Prop end):

Only the fuel pump has any significant exposure to heat... the rest of the critical components are either well forward of the power turbine NGV and Spider, or are decently shielded. The turboprop will drop right onto this base.

TurboProp | Home