Jump to content

Isolation switch


Recommended Posts

I am new to electric propulsion and on the steep learning curve.

 

I have yet to even plug in stuff and am fully aware of prop danger.

 

Is there a heavy duty power switch to isolate the motor from the battery ?

 

I have been advised to allow the ESC to power the Rx, so wondered about a hd power switch for the motor.

 

If the ESC is powered on and outputting to the motor, with the motor disconnected either by hd switch or motor wires, will be ESC be damaged ?

 

The motor is 3 phase so the switch will have to have 3 inbuilt switches moved in unison.

 

Or am I being paranoid with this.

 

There will be more seemingly daft questions, but if you don't know it are not sure, it's best to ask. Please help gentle.

Link to comment
Share on other sites

Thanks for the replies so far, will read up the threads mentioned.

 

Will the ESC be damaged if powered up and not connected to the motor and the tx tells the ESC to allow power to the motor, accidentally or otherwise.

 

When the deans connectors arrive for tge charger lead " converter lead" I will be commencing my radio playing with electric power on the bench, motor mounted and clamped to bench, propless.

 

My first experience with 2.4 radio and electric power, so a steep learning curve. I understand a set procedure has to be followed so motor will run, but that bag of sweets is for the weekend, no rush.

 

Was thinking about fitting the 4max bundle £25 setup in a double scale kk ff t + r + e Lysander or kit kk0042, 18inch doubled up to 36inch, no aerobatics.

 

I have the remains of a parkfly Piper cub ish foamy as an alternative, a scaled up chipmunk guillows 903 to 34inch, but all those are one or 2 of my winter project.

 

I have to relearn how to crawl first via powered glider and slope soarer...

Edited by Rich Griff
Link to comment
Share on other sites

Rich

The ESC is not damaged if the motor is not connected. It does a check to make sure the motor is connected correctly before it will 'arm'. With no motor connected it will just sit there doing nothing no matter what the receiver tells it to do.

Many ESCs have a BEC (Battery Eliminator Circuit) built in which supplies a constant 5V power to the receiver and servos. It is completely independent of the speed control circuit so will operate as soon as the battery is connected.

 

I am firm believer that the safest way to isolate the motor and prop (and everything else!) is to physically unplug the battery. I try to arrange that with all my designs this is readily simple to do without dismantling anything.

 

My 8 currently flyable planes than have to be assembled the battery is installed and plugged in afterwards.

Edited by Simon Chaddock
  • Like 1
Link to comment
Share on other sites

28 minutes ago, Simon Chaddock said:

I am firm believer that the safest way to isolate the motor and prop (and everything else!) is to physically unplug the battery. I try to arrange that with all my designs this is readily simple to do without dismantling anything.

 

My 8 currently flyable planes than have to be assembled the battery is installed and plugged in afterwards.

 

This is good advice, but unfortunately it's not always possible. On some ARTF designs the battery hatch seems to have been placed in precisely the worst position they could think of - for instance on my Sebart Miss Wind the hatch is unbelieveablely secured by a screw approximately 5mm behind the prop arc! Completely ridiculous, especially on a model expressly designed for electric power...

 

image.png.582d4a930d7f0c7a11b2f7e6dc2fb0f9.png

 

I've  re-engineered it with magnets, but if that hadn't have been possible the only options would have been an isolating plug as per @Denis Watkins post or a multi-layered throttle arming setup on the TX. Being an OpenTX user I have implemented the latter in addition to the magnet hack as after ~10 years on 2.4 with open source TXs I am more confident in that as a safety measure than an isolating switch; besides, I know sods law would decree I left the arming plug at home every time I headed to the patch! It's also a lot easier for me to implement and doesn't make an unsightly hole in the fuselage that would have required strengthening. I do accept that relying on a software solution is not for everyone though (especially if your TX functionality is limited), so go with whatever you feel comfortable with @Rich Griff.

Edited by MattyB
  • Like 2
Link to comment
Share on other sites

Thanks Marty, yes, as hassle free as possible, hopefully " fool proof" and "fail "safe"" too.

 

Read tooo many " the lipo flew out" , " the battery moved altering..." and "radio failure put down to battery problems" , determined not to let that happen to me.

 

The only crash I want is " pilot error" which are the best type arnt they ?! 🌋

Link to comment
Share on other sites

14 minutes ago, Rich Griff said:

Thanks Marty, yes, as hassle free as possible, hopefully " fool proof" and "fail "safe"" too.

 

Read tooo many " the lipo flew out" , " the battery moved altering..." and "radio failure put down to battery problems" , determined not to let that happen to me.

 

The only crash I want is " pilot error" which are the best type arnt they ?! 🌋

 

Please, lets not pull this off topic with more discussions of how to secure batteries - if you want to entomb yours in plywood that is up to you 😉, but those of us who have been flying electric a long time know that there is nothing wrong with velcro and a bit of foam packing done correctly.

Edited by MattyB
  • Like 1
Link to comment
Share on other sites

5 minutes ago, Rich Griff said:

Deans connection just arrived, ordered yesterday from 4 max.

 

I know see what George ment by the other connectors being better quality and more user friendly.

 

My bag of sweet for tonight...

I agree with George. I prefer the XT connectors having used both.

Link to comment
Share on other sites

I'm with Simon Chaddick on this one. Plug in battery = motor is hot.

 

I also use a rotary switch on the TX as a motor cutoff (the same rotary for all my IC, too). I'm perfectly happy about this being a thing on the TX - the TX has to be powered and talking to the RX before the servo signal will go live and output to the ESC; plus 'throttle high' when switching on TX, and choosing the right model memory. A few barriers before anything spins. Note, leaving the TX switched off prevents any of this from being bypassed, so that's another barrier.

 

But as stated not always possible on ARTF, here I would use an arming plug on the lipo exactly as per Denis' post.

Link to comment
Share on other sites

Throttle high when turning on tx ?

 

I think I read somewhere that the tx will only make the motor " hot" as in "live" when a set sequence is performed on the tx ? A safety feature ?

 

The Rotory "motor kill switch" is a good idea.

 

All this to come for me this weekend in the model room  when I eventually get to bench set up the radio gear...

Link to comment
Share on other sites

3 hours ago, MattyB said:

 

 I know sods law would decree I left the arming plug at home every time I headed to the patch!


I clip mine to the neck strap. The arming plug is only inserted when I'm on the flying patch, and removed before leaving the patch.

I keep a spare in the flight box.

Link to comment
Share on other sites

  • 2 weeks later...

You can’t have too many arming plugs ( mine are XTs )  - I have one in my flight box, another in the Tx case & each plane which has to have a wing taken off to change the flight battery, has it’s own plug which is attached to the airframe with a rubber band. Anyway it’s not exactly a terrible fag to make these arming plugs, and it’s good way to sharpen up my soldering skills.

Oh and there’s an XT60 arming plug on my car key ring too - Yes, I have arrived at the field without an arming plug - - - ONCE!! ( & on different occasions my Tx case & my Lipo box - but over 50-odd years flying, who hasn’t ).
 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...