Launch Controller Key Switch w/Non-Removable Key in On Position

[Joe Maguire]

Now that I have found some clear and understandable plans for a single-pad wired relay launch controller (kudos to jsdemar for those plans!), I am going to try to build a launch control system. One stumbling block I have encountered is finding a 12V key switch that cannot be removed when the switch is in the On position. To me, that's a basic safety feature that prevents someone from accidentally walking away with an armed system that appears unarmed at a glance. Can someone recommend a key switch with a non-removable On position key?

On a semi-related note, there's a Fry's Electronics store near me where I think I can get most of the items from those plans that are non-Radio Shack parts. What are some of your favorite places for buying electronic parts? Since I am something of a newbie, price is secondary to customer service, i.e. someone I can talk to who can understand my questions and make recommendations based on the specifications on the parts list.

 

[Steve Shannon]

Digikey has several.
Www.digikey.com

Or you can go for easy:
Momentary Switch Lock, Keyed Alike, Key Removable in OFF Position, with 2 Keys & Nut https://www.amazon.com/dp/B00VVQUKEI/?tag=skimlinks_replacement-20

 

[Samuron]

I used this one:

https://www.mouser.com/ProductDetai...=sGAEpiMZZMt3hSNP33T8/M/MT0FXg0pwXOPx6qfAJVg=

 

[sghioto]

ALL Electronics is a good source.
https://www.allelectronics.com/

 

[SteveThatcher]

here is one on Digikey that I found for a friend's L3 switch. Key is removeable in one position and it is a SPDT switch, so you can remove the key to disarm the launch controller. It is also less than $6.

https://www.digikey.com/product-detail/en/e-switch/KO103C701/EG2623-ND/502087

here is the NKK switch I used in the handheld launch button when I designed Veri-Fire. It is $13 and a smaller switch

https://www.digikey.com/product-detail/en/nkk-switches/SK12BAW01/360-1936-ND/1007014

 

[ep29030]

Now that I have found some clear and understandable plans for a single-pad wired relay launch controller (kudos to jsdemar for those plans!), I am going to try to build a launch control system. One stumbling block I have encountered is finding a 12V key switch that cannot be removed when the switch is in the On position. To me, that's a basic safety feature that prevents someone from accidentally walking away with an armed system that appears unarmed at a glance. Can someone recommend a key switch with a non-removable On position key?

On a semi-related note, there's a Fry's Electronics store near me where I think I can get most of the items from those plans that are non-Radio Shack parts. What are some of your favorite places for buying electronic parts? Since I am something of a newbie, price is secondary to customer service, i.e. someone I can talk to who can understand my questions and make recommendations based on the specifications on the parts list.

 

[ep29030]

I've always used a 1/4" mono phono jack for my launcher key. it is wired to itself, so when I insert it in the panel, it completes the circuit. Easy to replace. I keep a spare in my launch equipment. Just remove it and put it in my pocket until time to launch.

 

[SteveThatcher]

I've always used a 1/4" mono phono jack for my launcher key. it is wired to itself, so when I insert it in the panel, it completes the circuit. Easy to replace. I keep a spare in my launch equipment. Just remove it and put it in my pocket until time to launch.

and you can use a 10-32 machine screw as a key too... I am sure you meant phone jack instead of phono jack. A phono jack doesn't have a size and it changed names a number of years ago to RCA jack/plug for some unknown reason to me, but they still are used for turntable connections. The phone jacks and plugs are what you find on headphones and they are 1/4", 1/8" and metric sizes these days.

 

[Tobor]

I used an RCA plug, shorted with a solder bridge, as a key for my home made LPR launch controller back in the 80's.

 

[Joe Maguire]

This is going off-course. I am looking for a key switch (one that cannot be removed in the “on” position), not an RCA plug nor a machine screw key. I’m trying to make this a good project, not a Rube Goldberg contraption.

 

[Steve Shannon]

This is going off-course. I am looking for a key switch (one that cannot be removed in the “on” position), not an RCA plug nor a machine screw key. I’m trying to make this a good project, not a Rube Goldberg contraption.

Three different people already provided exact links to the switch you’re looking for. You didn’t even comment on those. How many more are you looking for?
Conversations meander, especially online. Others may enjoy reading about other solutions.

 

[vance2loud]

Automotive or agricultural ignition switches are another option that tend to have higher amp ratings.

 

[SteveThatcher]

Automotive or agricultural ignition switches are another option that tend to have higher amp ratings.

a high current switch for a relay based launch controller isn't required. The relay and battery would be near the pad. The launch controller simply actuates the relay over smaller wires.

 

[Glasspack]

Joe, Don't get irritated with all the helpful hints from experienced rocketeers......

Here is my two cents added... I built my own four pad controller. With help from my great friend Joe (RIP).
Based off of the foundations of others before me. I have been an aircraft ECS/Electrician for years so I felt
I could do it. I used the switch just like the one in the beginning of your post suggested by Steve Shannon.

Here is what mine looks like....... This Controller connects to the box at the Pad. I have a 12V 12AH
battery for power and can put 20A to the igniters.....The image shows the "Master Power" Key Switch
Its a nice switch.
Tells us what you decided to go with.....

 

[Glasspack]

Joe, Don't get irritated with all the helpful hints from experienced rocketeers......

Here is my two cents added... I built my own four pad controller. With help from my great friend Joe (RIP).
Based off of the foundations of others before me. I have been an aircraft ECS/Electrician for years so I felt
I could do it. I used the switch just like the one in the beginning of your post suggested by Steve Shannon.

Here is what mine looks like....... This Controller connects to the box at the Pad. I have a 12V 12AH
battery for power and can put 20A to the igniters.....The image shows the "Master Power" Key Switch
Its a nice switch.
Tells us what you decided to go with.....
View attachment 361009 View attachment 361009

 

[Steve Shannon]

Joe, Don't get irritated with all the helpful hints from experienced rocketeers......

Here is my two cents added... I built my own four pad controller. With help from my great friend Joe (RIP).
Based off of the foundations of others before me. I have been an aircraft ECS/Electrician for years so I felt
I could do it. I used the switch just like the one in the beginning of your post suggested by Steve Shannon.

Here is what mine looks like....... This Controller connects to the box at the Pad. I have a 12V 12AH
battery for power and can put 20A to the igniters.....The image shows the "Master Power" Key Switch
Its a nice switch.
Tells us what you decided to go with.....
View attachment 361009 View attachment 361009

That turned out really good, Glasspack!

 

[MikeyDSlagle]

You can grab an ATV key switch for around 7 bucks I think. Can be wired to remove the key in either on or off position.