Rob Johnston has just started importing RC- Electronics range of electronic components for RC Soaring . These include sensors for GPS , Altitude , Temperature and Voltage which can either be logged on board or downlinked for GPS Triangle Racing . Rob asked me to test and comment on the F5J altitude switch and reader .
The units available include ; RC Multi 2 , a small unit which combines data logger for altitude , voltage and temperature sensors , a time base and switch to stop the flight motor at a preprogrammed altitude or time to comply with the various electric soaring tasks .
RC FXJ Programming Card
RC Multi 2 Data Logger , Alt & Temp Sensor
GPS Sensor
The unit is 28 x 14 x 6mm and weighs 6gm including the cables .
A small GPS receiver can be plugged into the RC Multi , its data is also recorded by the RC Multi .
Some tasks limit altitude and others time . F5J for example requires a max motor run of 30 seconds and to record the altitude 10 seconds after the motor is stopped ( to cover any potential zoom climb after cut off ).
Using the RC FXJ Programming Card , recorded altitude can be read after flight on a small LCD screen - this unit can also be used to program the required limits . The altitude displayed is the max altitude between motor cut off and 10 seconds after cut off as required by the F5J rules .
The RC Multi can also be plugged via a supplied USB cable to a computer to download detailed recorded data such as altitude , vario , temperature , voltage and GPS positions .
The RC Multi does permit motor restart . This is not permitted in f5j , restarts cannot be checked by any means other than looking at the PC data . It is possible to make the RC Multi F5J legal by flashing the firm ware ... In accordance with those rules , once flashed the unit can not be re flashed to original to prevent cheating . Flashing the unit is not required by NZ Soaring rules - only if traveling to international contests .
In use ... I started by visiting the RC-Electronics website and downloading PC software . Once installed I plugged the RCMulti into the PC . The software quickly detected the RC Multi and offered to download the data and also to update the firmware in the unit . Once updated I was able to set the cut off parameters for the tests - both 30 seconds and 200M .
The RC Multi was then installed in my E-Supra in line with the throttle connection between the RX and ESC . The GPS unit was then plugged into the RC Multi .
Andrew Palmer has an E-Onyx with a similarly capable switch and meter so we test flew together to compare the devices and have a wee bit of competition .
Both models were fired up and launched simultaneously and climbed out at about a 60 degree angle . Andrews model , being grossly over powered got to 200m a few seconds before mine , in about 20 seconds . Both models motors stopped at 200m and leveled off . A quick glance at the altitude download to my JR XG8 transmitter showed an altitude of 209M which seems pretty accurate given the zoom after motor cut off . We then proceeded to fly around for a while chasing thermals . I recorded several flights that day . Later at home the data was downloaded and then at the prompt from the software , deleted . After that I unplugged the RC Multi which promptly closed the program loosing all the data- so save the data or don ' t delete it from the RC Multi until its well finished with !
The next day I flew from home to record some new data to add to the report .