Fuel Monitor for Turbines

With our Sensorhub firmware we have a very good opportunity to monitor the fuel consumption on turbine driven models.

It works very similar to our battery management, the pilot will be announced to land at a adjustable value. Within the flight we will announce each 10% of the "volume for flight" - so even if 0% is reached he still has the dialed in reserve fuel left to land carefully.

Therefore we need a NEO (VBasic is ok) with the Sensorhub firmware. This is a universal telemetry device w/o any receiving or control functions. it has alot of inputs with different resolutions which can be used for own purpose. As nearly all telemetry devices it can be chained at the telemetry bus with others of course.

The hardware consists of a flowmeter which is suitable for RC voltage and delivers pulses depending on the fuel flow. We use a Biotech FCH-m-POM-LC. This will be connected in the fuel supply with some FESTO adapters. Please use some im M5 with inner thread , this will be self-sealing. Also take care of the flow direction. Connect it to the NEO with a modified patch cable (see drawing!) at the AUX3 port.

In addition you can also connect a simple voltage divider to one of the low res inputs (hi res isn't needed) for turbine battery monitoring. The flight pack will usually be monitorred by the master NEO (2s direct use except using a battery backer or BEC). If a BEC or battery backer is used - monitor the rc batteries in the same way as the turbine battery (voltage divider). Set up threshold and alarm for each - done.

If you also mount a magnet/halkl sensor at the main shaft (3 active magnets, set gear ratio to 3) and connect to master NEO RPM input - you will be able to monitor and log the headspeed too.There is a app available to set alar at over/underspeeding as well. A installed Mikado temperature sensor at TELE1 will be logged additional (e.g. set alarm as fire detector in the fuselage).

My UH-1D looks like this:

 

A look inside the model. The white NEO is the Sensorhub. The plug on the flowmeter is secured with some hot glue. On the right side you can see the turbine battery voltage monitoring connected to the balancer socket.

 
 

Here the configuration as exaple, Sensorhub and Fuelmeter apps must be installed. The voltage must be calibrated with a multimeter (measure battery voltage and set the max value until it matches). The pulse count should be set up as per manual and altered with some "fuel only" test runs with the pump (use GSU) into a beaker. If you take the same sensor as i did - a  Biotech FCH-m-POM-LC w/o the 1mm nozzle - it will be around 19 pulses which is enough accuracy for one flight. Using the 1mm nozzle - we might be around 115 pulses (1/8 UNF Adapter required).

 

My fuel tank settings - i have always enoogh reserve ... 0% announcement is still with 25% left in tank w/o the additional hopper tank volume.

 

Some screenshots from my display for the UH-1D:

 

Here the after flight logs - also available in the cloud.