Restraining electric aircraft

[Trevor 25]

I would just like to remind people who fly electric planes about restraining them even when they are not in use. Unlike ic engines, electric motors can start by themselves. It is all too easy to forget to unplug the battery after a flight then, when the transmitter is turned on for the next model the electric one can start up. Another scenario is if the Tx fail safe is set incorrectly and when the transmitter is turned off, the plane can go to full throttle.

 

This could occur in the pits area with lots of people in close proximity and these planes can potentially cause a lot of damage to people and property so please make sure you use them safely.

[arun 0]

Absolutely agree - have seen three near misses (from memory) caused by unrestrained electrics! And remember, an electric won't stall when it hits flesh - it will keep chopping and drawing more and more current.

 

In addition it is worth having a switchable throttle curve that stops the throttle stick having any effect until you are ready - I use this (is coloured red on my TX) and is only armed when the plane is on the strip. For larger electrics I have actually used dual-arming switches to make sure the motor is on only when I have made a very conscious decision for it to be on. If anyone needs help programming this on Futaba, PM me - but you will need a radio with programmable throttle curve.

 

Some smaller foam electrics cannot be restrained in the conventional way due to their size. In this case I guess extreme caution is the most pragmatic approach and maybe arming the battery on the strip?

[Trevor 25]

Here is a useful RCM&E video about electric model aircraft safety

http://www.youtube.com/watch?v=U9l8uHN5W8g‎

[Pilot Ben 28]

 

yes, and it's also a reminder to set failsafe correctly, and to set throttle cut,as ET almost had a nastry accident with a unrestrained wot 4 and it chewed into a table, whilst throwing bits of prop at him. A costly reminder that electric planes are NOT as easy as everyone thinks....

 

[Martin 0]

 

I don't think you mean throttle cut for electric. You probably mean an "arming switch" (there are probably other names used too) - i.e. a switch that forces throttle to minimum except for one "armed" position where throttle behaves normally, like Arun describes earlier in this thread.

 

I'm aware of three ways of doing this, and there's almost certainly a better way on a Taranis.

 

• Using a switchable mix: mix throttle to throttle, -100% (so when the mix is active the throttle stick cancels itself out), then use the other settings for the mix to set the actual output at that time. (I've also been pointed towards using two mixes to achieve the same end, but I haven't tried that myself.)

• Using a switchable throttle curve: set up an alternate curve with all output points zero. When this curve is active the throttle will be forced to zero.

On suitable transmitters (Futaba 8FGS certainly does this), mapping the throttle channel (3, for Futaba) to "MOTOR" function rather than "THROTTLE" indicates to the transmitter that it's an electric motor, and there is then a "MOTOR" menu which specifically provides a safety switch feature. This is my preferred option if the Tx supports it, as it provides extra useful safety features (e.g. at switch-on the Tx will complain and won't transmit until the switch is moved to safe, like it does for throttle stick position). This is a feature of certain mid-range (and higher?) Futaba transmitters, but other manufacturers may have something similar.

 

 

There is more information about this on this older thread: viewtopic.php?f=12&t=4196

 

FWIW, I've now switched to the MOTOR function (Futaba specific) for electric aircraft, and a single mix for IC aircraft (because the interaction with trims is slightly less annoying than for throttle curve...)

 

[funflyjames 19]

 

Ben, I'm so pleased that you are aware of the need to set the failsafe correctly. I'm always amazed how many people don't know that ALL failsafes have to be set to turn the power off on loss of signal. This is a regulation that everyone MUST stick to.

Well done Ben.

 

[Bravedan 106]

 

Many Tx makers could learn from the quad makers, where arming their controller is often locked out unless via holding full down right on the left stick for x seconds and is the only way to make the quad live. In their case as they never glide deadstick a couple of seconds of no throttle means an automatic re-arm before it will run again, maybe this bit isn't good for FW as is , but it could be adapted to include the absence of any flight surface operation or some such.

 

The point is, it is self activating.

 

Obviously model match or equiv helps if you move on and don't isolate the old model, too.

 

[Bravedan 106]

 

I'm always amazed how many people don't know that ALL failsafes have to be set to turn the power off on loss of signal. This is a regulation that everyone MUST stick to.

 

 

Sorry James, but (a) not everyone CAN, and (b) some aircraft like multicopters must NOT turn the power off on loss of signal!

 

There are more Tx/Rx around which do not allow it than you might think, and that includes some 2.4HGz like quite a few Futaba.

 

Killing the motors on a multicopter on loss of signal is downright dangerous!!

 

(You did say aircraft, ALL, and everyone MUST)

 

[Pilot Ben 28]

Another reminder to be careful when running electric aircraft. I have very nearly just lost my fingers after a bench running accident. To tell the truth, 20 mins after the incident my hands are still shaking. 

Whilst bench running a 3S setup for my Equaliser, the prop ate the ESC, and very nearly my fingers. I was standing behind the prop, and had just reached under the prop arc to unplug the battery wires, when the motor started, I can only assume as a result of me accidentally turning the servo tester. The prop hit the ESC, shattering, with pieces then flying very close to my head. For the entire test I was behind the prop, having only gone into line with it at the end of my test. A very harsh reminder, and one that shall cost me £30 for a new ESC, but this time round little else. I shall now make a new rig where all of the electronics are clearly behind the prop, not just under it.

The ESC shielding plate has been sliced and severely dented, one capacitor dented, and the other somewhere in the garage.

The ESC is now hanging above my bench as a reminder for the future. 

Please be careful.

Edited May 5, 2018 by Pilot Ben