ESC switch

model14

Active member
I am new to flying mini electric planes. I know that keeping the weight down is really important. My ESC does not have an On/Off switch (I note that TF's does not either). Can I wire in a micro slide switch in the BEC power lead to the receiver so that with it Off the receiver will not send a signal to the ESC, and the ESC will not try to power the motor? I don't want to wire a switch into the battery lead to the ESC (heavy). Do most of you just not use a switch and just unplug the battery between flights?
 

AIRFORGE

Make It Fly!
Moderator
Using a switch will only be effective if inline with the battery to esc wires. Otherwise, If a lipo is left connected to an esc, with an internal power switch, it will discharge.
 

HVB79

Member
On smaller electric planes, switches don't provide any value. Extra weight, cost and just one more part that can fail.

The flight battery needs to be swapped between every flight anyway so save the weight and simply use that as the switch. The other problem is that many small switches are unreliable and easy to damage. A bad switch can cause your control system to turn off mid-flight.

As to your specific idea to put a switch between the ESC and receiver this is not a good idea because it will NOT cut the power to the ESC and by extension the motor but instead only cut power to the receiver. The ESC will go into failsafe mode and if it is set correctly, the throttle will go to zero, but if set incorrectly the motor could spin up. In any case the ESC will still be pulling some power from the battery and will discharge it to zero and ruin the battery if left plugged in over night.

If you must have a switch it should to be between the battery and the ESC so that the power is completely turned off when the switch is open.
 

FoamyDM

Building Fool-Flying Noob
Moderator
On larger planes, I've seen an "arming plug" which is used to power up the plane when ready. It's usually a small loop of wire connected to a connector that plugs into the outside of the plane completing the electrical circuit. I found these samples with a quick Google search: https://rcdude.com/products/connectors-cables/arming-switches.html
I really like the Arming Switch Idea! as a quick on-off, without having to dismantle my planes. Very Nice!
 

Tench745

Master member
I really like the Arming Switch Idea! as a quick on-off, without having to dismantle my planes. Very Nice!
I added an arming plug on my Dumod build because getting to the batteries to unplug them involves flipping the plane onto it's back and unbolting the wing. I liked the added safety of keeping the ESCs unpowered until the plane was all set up and ready to fly. Not really worth the weight or complexity on smaller aircraft though.
If you use a switch instead of a plug for powering the RX you may want to consider either redundant switches, or a failsafe switch that won't cut power to your RX if it fails mid flight.