Converting a 'hotRC' 2.4gHz transmitter for Electric Control Line remote start/stop

by Roger Silcock
This conversion applies to the very reasonably priced 'hotRC' transmitter and receiver combination available from Aliexpress. I converted the transmitter to include a removable remote push button so that I dangle the transmitter on my left wrist and hold the remote button box in my left hand ready to start or stop the motor. I then control the aircraft with the control handle in my right. I had found it impossible to locate the small button controlling the motor (ch5) quickly enough with an impending crash to turn the drive off and prevent damage to the esc. See below a standard transmitter and a modified one with a remote push button box.

Remove the rear cover unscrewing the three small screws, and unplug the battery and displav connectors Drill a 3mm hole in the recess for the wrist strap as shown for the servo extension cable male end.

Unscrew the four small screws holding the printed circuit board in place. Carefully withdraw the pcb and expose the tiny push buttons. I use channel 5 button to start and stop the motor. Carefully solder the outer wires on each of the two button 'feet' already soldered to the board. They can be either way round.

Refit the components and pcb in the body and refit the four screws. Re connect the display and battery. Refit the rear cover. The push button is a N/O momentary operation button. The N/O contacts should be connected to the outer two wires of the female end of the servo extension cable. I suggest installing the button in a small plastic box.

Setting up the system on the aircraft.

Connect the three male motor cables to the three female esc cables in any order. If the motor runs backwards swap two of these connections. Connect the esc three pin plug into the CH5 connector of the receiver. To complete the installation the battery should be plugged in to the esc two pin plug. For safety the battery connector should accessible and only connected when the plane is to be flown. The control action is: Press and release the button and the motor starts. Press and release the button again and the motor stops.