logo Heading














































































Derek Knight's new E30 controller

Derek has revised his Free Flight E30 controller specifically for E30 competition. The changes he has made are:-

  1. Maximum motor run time of 65 secs
  2. A signal for a servo DT driven from the reassigned decay pot
  3. Maximum DT time of 320 secs
  4. Controller boots on connecting the battery but motor does not run until a switch press.

A test set up using this controller is shown below driving a brushless motor through a 3amp 1s Micron ESC, a 70mah LiPo and a 2.5gm servo from the scrapbox.


The motor start switch is far right and is configured as a 'push to make'. The DT is timed from motor stop and the servo moves CW full scale for 2-3 secs and then returns to original position.
On completion of the DT function, the motor cannot be restarted unless the battery is unplugged and replugged. Pressing the motor start switch has no effect. The retriever, therefore, cannot restart the motor.

I would usually run a miniature slide switch in the ESC negative conductor to allow a reboot. Since the battery has to be disconnected after each motor run for recharging, this switch is redundant. On the grounds of simplicity. I will probably leave it out.

Although Derek has labelled this as a brushless motor controller, I suspect that it is quite capable of running a brushed motor (if that is your preference). I cannot see why you would want to, but there is no accounting for taste.

The circuit diagram for the above power system is shown below.

Circuit Diagram

The sole drawback of this controller is the requirement to solder the motor start switch across the A and B terminals. The solder pads are small and a soldering iron with a 1mm tip helps no end.

Note the S3 S2 S1 pads. These are pads to provide alternative functionality for different versions of the controller. It also shows Derek's commitment to current and future variants.

System installation

My latest E30 design, E30_migrus_8, was chosen to feature the controller. This is a high thrust line layout with 33 degrees wing sweepback and a 'Butterfly' back end , plagiarised from a Mick Page DLG. The wing is bolt on using 2 off 6BA plastic screws. Sweepback is the way in which wing area can be increased within the 30" span restriction without degrading the aspect ratio.

E30 Migrus 8

E30 migrus 8

The power unit installation is shown below …..


The DT servo is in the position occupied by the Tomy wiggler and has the operating lever removed and replaced with a cross drilled 0.5mm CF rod.


The system boots when the battery is connected and the motor starts when the push button is pressed.

With the cover replaced, the fuselage pod looks like this………..

Cover in place

Flight testing when the weather improves.

Ian Middlemiss   -  Contact e-mail address
 December 2011