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.