This electric free flight timer was developed for the needs of E36 competition models that are not met by the current electric free flight 'sport' timer the EFF3, seen elsewhere on this site.
The specification, functionality and packaging of the MK1 were originally guided by John Thompson the SAM1066 Chairman and experienced international contest flier. In comparison with the EFF3, the unit needed to be accommodated within the fuselage with just the push button and LED showing through a ply mounting plate affixed to the timer on short stand-offs. The power setting potentiometer was not required as only full power is used and neither were the motor soft start and run down required. A maximum motor run time of 20 seconds was specified but unlike the EFF3 the time period requires to be set to a resolution of 0.1secs.
For competion use, the timer operation was altered so that the motor starts upon pressing the button but the timing period doesn't begin until the button is released. Should the button be released but the model not launched, pressing and holding the button again will reset the timing period back to zero. Thus you can wait for that optimum moment to launch - ie catch the thermal detected by your upwind monitoring station when it arrives at the launching position. In contrast, the EFF3 motor and timing period both start together when the button is released - and you can't hold the button pressed for more than 2 seconds or you enter the set-up routine. Should a dangerous launch occur, John considered it would be useful if the RDT system could be used to first kill the motor and then at a later, safer time (for the model) be used again to operate the DT servo - RDT motor kill is a further benefit not enjoyed by the EFF3.
Following the sad demise of John Thompson I've since teamed up with Tony Shepherd - this has resulted in an improved MK2 version. The scope of its functionality is broadly the same but I have introduced an improved set-up routine that allows the user to jump directly to adjust the appropriate parameter rather than having to scroll through all of them in turn until the desired parameter is reached. This new set-up routine also allows long timing durations to be set with fewer button presses without sacrificing timing resolution. Menu navigation is easier than that of the EFF3 by the use of a three colour LED rather than a single colour LED.
Also the timed DT period used to be hard programmed at a user specified duration at the time of purchase as the expectation was that RDT would be routinely used to terminate every flight - and the fixed period timed DT was merely a safeguard against RDT malfunction. However, user feedback has resulted in the timed DT period being made user adjustable.
Note that unlike the EFF3 'sport' timer, the E36 Timer features 0.1 sec timing resolution allowing you to adjust for the indeterminate time it takes the prop to stop - so for example, rather than having to set the timer to 9 secs as a 10 sec setting might give 10.4 secs until the prop stops, you can now set 9.6 secs to stay with this (example) 10 sec motor run allowance.
The DT servo is plugged into the timer and the RDT receiver plugs into a further connector on the timer to receive its power and to transfer its trip signal for processing by the timer. A further feature added was the capability to reverse the direction of operation of the DT servo to suit the user's installation.
Key Features
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