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Keyed Master Switch?

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andrewbutler(at)ireland.c
Guest

Posted: Fri Mar 14, 2008 6:45 am Post subject: Keyed Master Switch?

All,



I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone help with a method of enabling "key start" access to ignition/power?



I have dual paths to each ignition, so need four switches (to enable pre-flight checks of each path), so the documented adapted mag key start switch option won't work.



I can't get fully comfortable with a fully live system being just a flip of a switch away....... See attached to get the idea.



Best regards,



Andrew Butler

RV 71700 - West of Ireland.

Fueslage (right way up!)

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dennis.glaeser(at)eds.com
Guest

Posted: Fri Mar 14, 2008 7:56 am Post subject: Keyed Master Switch?

Consider putting a keyed switch in the Push Button Start circuit.  If

the key isn't on, the start button doesn't work!  One switch does the

trick and it doesn't put another switch (point of failure) in any of

your other critical circuits.

Your ignition systems may be live if their switches are flipped, but

nothing happens without the starter.



Dennis Glaeser

RV7A - Subaru H6 - DAR inspection next week!



-----------------------------------------

I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone

help with a method of enabling "key start" access to ignition/power?



I have dual paths to each ignition, so need four switches (to enable

pre-flight checks of each path), so the documented adapted mag key start

switch option won't work.



I can't get fully comfortable with a fully live system being just a flip

of a switch away....... See attached to get the idea.



Best regards,



Andrew Butler

RV 71700 - West of Ireland.

Fueslage (right way up!)

ctbecker

Joined: 14 May 2006
Posts: 9

Posted: Fri Mar 14, 2008 11:12 am Post subject: Keyed Master Switch?

Dennis has the right idea, especially in light of all the 

emphasis on '2 locks'.  My 8A will have a key switch 

between the battery and the starter switch.  The actual 

starter switch will be on the stick, controlling a relay 

in the starter circuit.



Charlie Becker

N464CB(r)  8A(e)

Finishing

On Fri, 14 Mar 2008 11:51:42 -0400

  "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> wrote:

 	  Quote: 	
		   

Dennis A" <dennis.glaeser(at)eds.com>

 

 Consider putting a keyed switch in the Push Button Start 

circuit.  If

 the key isn't on, the start button doesn't work!  One 

switch does the

 trick and it doesn't put another switch (point of 

failure) in any of

 your other critical circuits.

 Your ignition systems may be live if their switches are 

flipped, but

 nothing happens without the starter.

 

 Dennis Glaeser

 RV7A - Subaru H6 - DAR inspection next week!

 

 -----------------------------------------

 I plan on a PUSH Button Start and Dual Electonic 

Ignition. Can anyone

 help with a method of enabling "key start" access to 

ignition/power?

 

 I have dual paths to each ignition, so need four 

switches (to enable

 pre-flight checks of each path), so the documented 

adapted mag key start

 switch option won't work.

 

 I can't get fully comfortable with a fully live system 

being just a flip

 of a switch away....... See attached to get the idea.

 

 Best regards,

 

 Andrew Butler

 RV 71700 - West of Ireland.

Fueslage (right way up!)

 

 

 

Un/Subscription,

http://www.matronics.com/Navigator?AeroElectric-List

Forums!

Admin.

Terry Watson

Joined: 09 Jan 2006
Posts: 290
Location: Seattle, WA USA

Posted: Fri Mar 14, 2008 12:55 pm Post subject: Keyed Master Switch?

My plan has been to put a simple toggle switch in the baggage compartment

that disconnects the starter switch. Hopefully this plus a canopy lock will

meet the 2 lock requirement. The baggage compartment will also have a lock.

I wonder how many times I will get all strapped in before I realize I

haven't enabled the starter switch. 



Terry

RV-8A wiring



--

mprather(at)spro.net
Guest

Posted: Fri Mar 14, 2008 1:44 pm Post subject: Keyed Master Switch?

Do you plan to put a guard on the switch (or cover) to keep loose items in

the baggage compartment from bumping it?  I suppose that in flight you

probably won't have to engage the starter ever should that happen.  If you

fly the plane long enough without a guard on that switch, you'll

eventually be in a situation where you can't figure out why you can't

engage the starter - after giving somebody a ride maybe, or trying to

restart after a fuel stop..



Will the switch be in a place where it interferes with loading things into

the baggage compartment?  Will you have to unload anything form the

compartment in order to gain access to the switch?

Matt-



[quote] 

 <terry(at)tcwatson.com>



 My plan has been to put a simple toggle switch in the baggage compartment

 that disconnects the starter switch. Hopefully this plus a canopy lock

 will

 meet the 2 lock requirement. The baggage compartment will also have a

 lock.

 I wonder how many times I will get all strapped in before I realize I

 haven't enabled the starter switch.



 Terry

 RV-8A wiring



 --

Terry Watson

Joined: 09 Jan 2006
Posts: 290
Location: Seattle, WA USA

Posted: Fri Mar 14, 2008 3:57 pm Post subject: Keyed Master Switch?

Those are all good considerations, but having it on the starter circuit

rather than ignition makes them a little less critical. The switch guard is

probably pretty important. I would not expect to always use the switch to

disconnect the starter when leaving the airplane, but more for away from

home, overnight -- just one more safeguard, and of course one more point of

possible failure.



I am willing to be convinced that it is not a good idea.



Terry

 



--

Dennis Glaeser

Joined: 10 Jan 2006
Posts: 53
Location: Rochester Hills, Michigan

Posted: Fri Mar 14, 2008 5:49 pm Post subject: Keyed Master Switch?

Why not a key switch in a more convenient (in the cockpit somewhere)

location?  It doesn't have to be on the panel, maybe tucked away somewhere,

but reasonably easy to access. Then no post strap-in remorse, and if you use

the baggage compartment much at all, I predict you'll be removing or

relocating that switch before long.

If you are in a locked hangar, you probably won't use it unless you're away

from home.

Believe me, you're convenience and ease of use is most important.



Dennis



---------------------------------------------------------------------------

My plan has been to put a simple toggle switch in the baggage compartment

that disconnects the starter switch. Hopefully this plus a canopy lock will

meet the 2 lock requirement. The baggage compartment will also have a lock.

I wonder how many times I will get all strapped in before I realize I

haven't enabled the starter switch.



Terry

RV-8A wiring

andrewbutler(at)ireland.c
Guest

Posted: Sat Mar 15, 2008 5:30 am Post subject: Keyed Master Switch?

Hi Charlie,



What type of switch are you using and where did you source it?



Cheers, Andrew.

 

 [quote]---

Mark Sletten

Joined: 10 Jan 2006
Posts: 43
Location: St. Jacob, IL (Near St. Louis, MO)

Posted: Sat Mar 15, 2008 5:51 am Post subject: Keyed Master Switch?

Why not just use a standard keyed starter switch? Get rid of all the other

push button/toggle switches in the circuit. Power your electrical system

thru a standard toggle if you like and just use the starter side of the

keyed switch in the starter circuit.



Regards,



Mark

_________________
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com

klehman(at)albedo.net
Guest

Posted: Sat Mar 15, 2008 6:51 am Post subject: Keyed Master Switch?

Automotive and farm suppliers sell good key switches for around $12 and 

marine suppliers (at about twice the price) as well. Typically rated for 

a 25 amp starter solenoid load. I use one for the battery master and the 

spring loaded position cranks the engine. I like the fact that with the 

key in my pocket nobody can crank the engine accidentally, and that from 

cars we subconsciously associate keys with cranking. Also I think there 

is very little chance of the circuit staying energized after cranking 

since my fingers can force it back from the crank position even if the 

spring fails or the contacts try to weld.  Of course my starter solenoid 

can still physically stick, but not the switch I hope.

Ken



Mark Sletten wrote:

 	  Quote: 	
		   

 

 Why not just use a standard keyed starter switch? Get rid of all the other

 push button/toggle switches in the circuit. Power your electrical system

 thru a standard toggle if you like and just use the starter side of the

 keyed switch in the starter circuit.

 

 Regards,

 

 Mark

Terry Watson

Joined: 09 Jan 2006
Posts: 290
Location: Seattle, WA USA

Posted: Sat Mar 15, 2008 8:31 am Post subject: Keyed Master Switch?

Think of it this way: I prefer combination locks to keyed locks because the

latter requires that I have the proper physical key with me while a

combination lock requires only that I know how to open it. What I am

proposing amounts to a combination lock on the ignition: you just have to

know where the switches are. Locking the baggage compartment where the

disconnect switch is located is that additional security feature that we are

now required to have.



When I was in college I bought a sad looking '50 Chevy sedan for $60. It

turned out to be a great car until I ran it low on oil and threw a rod, but

one of the great features was the ignition switch. Key use was optional. You

could turn it to the left with the key in it and remove the key and it was

locked, or you could just remove the key without turning it to the left and

it was still an ignition switch but didn't require a key.



Yes, canopy and baggage compartments will still require a key. My current

Mazda MX-5 only requires that I have the key in my pocket and it

"recognizes" me and allows me to open the doors or trunk and start the

engine. But that's way more complex than I want to go with my airplane.



Terry

--

steve(at)newtech.com
Guest

Posted: Sat Mar 15, 2008 10:50 am Post subject: Keyed Master Switch?

I like the idea of a shorting plug that will short the mag p leads to 

ground.  Insert the plug to disable the airplane.  Remove the plug to 

fly.  You really are not adding anything to fail in flight.  I will only 

be using it when away from my home field.  Simple, cheap and relatively 

free from unintended consequences (I think).



Steve Eberhart

RV-7A, Wiring up everything so I can finally fly this thing.



Andrew Butler wrote:

 	  Quote: 	
		   All,



 I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone 

 help with a method of enabling "key start" access to ignition/power?



 I have dual paths to each ignition, so need four switches (to enable 

 pre-flight checks of each path), so the documented adapted mag key 

 start switch option won't work.



 I can't get fully comfortable with a fully live system being just a 

 flip of a switch away....... See attached to get the idea.

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