FF4 and EI FT60 (red cubes)

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JFonseca
Posts: 2
Joined: Sun May 25, 2025 5:35 pm

FF4 and EI FT60 (red cubes)

Post by JFonseca »

Hi,

I am new to the forum and relatively new to aircraft ownership. I understand mechanics pretty well but electricity is not my thing, so excuse me in advance if my questions are too basic.

I have a Rotax 914 in my Stemme S10-VT. I have installed the EI FT60 fuel flow meters (red cube) but I did not make the electrical connections yet. I have 3 wires coming of the red cube (red, black and white). I want to connect it to the MGL FF4, but I don’t understand the instructions.

In the MGL instructions it says that a 5K6 resistor needs to be added. It shows the white wire from the red cube connected to the FF signal in the MGL RDAC and the resistor connecting the white wire and to FF +5V also in the RDAC. I don't have a MGL RDAC. Do I need to connect the red cube white wire to the yellow (or blue) FF4 cable, cables 6 (or 11)? And where do I connect the resistors? I assume I need to have 1 resistor for each red cube white cable, right?

And the FT-60 red and black cables? in the EI manual it says that it should be feed by the instrument, in my case the FF4. But I don't see where I can connect it. I think I need to connect to the 12V system, right?

Can anyone give me clear guidance in what I should do?
https://drive.google.com/file/d/1ID1_YO ... drive_link
https://drive.google.com/file/d/1-7pw-q ... drive_link
rainier
Site Admin
Posts: 770
Joined: Fri Aug 28, 2020 7:03 pm

Re: FF4 and EI FT60 (red cubes)

Post by rainier »

Your red cube needs a pull up resistor which is similar to most of them (except our MGL sender which has this already built in).
The resistor goes from your white wire (signal) to the red one (+12V). The actual value is not very critical. Usually anything around 3000-8000 ohms or so will work fine.
Make sure you enter the correct k-factor into the instrument. In case of U.S. made senders the k-factor is for one gallon of fuel while we work in liters so make sure to convert the number. k-factor is simply the number of pulses the sender creates for 1 liter of flow in our case.
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