Looking for key switch, removable in off position, 3/4" hole -- quickly.

Bat-mite

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Hi. Launching on 2/4. Just found that one of my switches is dead. It was one of these from Aerocon.

Aerocon has a minimum $15 order, and USPS Priority is another $15. I don't want to spend $30 for a $6 switch.

Does anyone:
  • Know where I can get one?
  • Know a Digi-Key part number, etc.?
  • Have one lying around that you could sell me and ship quickly?
Thanks!
 
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I got 2 from DigiKey, but the key is always removable which I don't like as the key keeps falling out. They were posted on here as the ones to get.
 

jsdemar

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This is what I use on my launch controllers:
 

Bat-mite

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Sorry. Typically the key is removable in the off position only so at a glance a person can tell the box is safe.
Interesting. I attach "Remove before flight" banners to my keys, so that if it is on the pad, I know it is not ready for flight if I see the banners waving.
 

Bat-mite

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This is what I use on my launch controllers:
With the four solder lugs, is there a way to wire it so that the key is removable in the ON position?
 

jsdemar

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With the four solder lugs, is there a way to wire it so that the key is removable in the ON position?
Not sure why you would want to do this.

The switch has two independent circuits. Each has a normally open and normally closed, so yes you can do that. Check with an ohmmeter.
 

Bat-mite

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Not sure why you would want to do this.
So that when I see the "Remove before flight" banner attached to the key, I know the electronics are not armed. Thus, if the rocket is on the pad and I have forgotten to arm the altimeters, either I or someone else will see the "remove before flight" tag and abort the launch. Once I arm the altimeters (key in the ON position), then I can remove the key and it is ready for flight.
 

jsdemar

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So that when I see the "Remove before flight" banner attached to the key, I know the electronics are not armed. Thus, if the rocket is on the pad and I have forgotten to arm the altimeters, either I or someone else will see the "remove before flight" tag and abort the launch. Once I arm the altimeters (key in the ON position), then I can remove the key and it is ready for flight.
This is the opposite of the recommendation in the safety code. When you see the flagged key, the pads aren't safe. Remove the key and the pads are safe.

You can also add an arming switch at the pads with a pulsing beeper to remind people at the pads to turn the arming switch off.
 

Steve Shannon

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This is the opposite of the recommendation in the safety code. When you see the flagged key, the pads aren't safe. Remove the key and the pads are safe.

You can also add an arming switch at the pads with a pulsing beeper to remind people at the pads to turn the arming switch off.
John,
I made the same assumption. He’s not asking about key switches for pad boxes. This is how he arms his avionics in his rocket. The flagged key is his version of a “remove before flight” tag.

I’m not a fan of key switches for this purpose. They are not built to be vibration resistant or acceleration resistant, and a found rocket cannot be easily disarmed, but there’s no rule against it.
 

jsdemar

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John,
I made the same assumption. He’s not asking about key switches for pad boxes. This is how he arms his avionics in his rocket. The flagged key is his version of a “remove before flight” tag.

I’m not a fan of key switches for this purpose. They are not built to be vibration resistant or acceleration resistant, and a found rocket cannot be easily disarmed, but there’s no rule against it.
Ah, ok. Never mind!

The switch I pointed has redundant circuits, but no vibration spec. Put both circuits in parallel and hope for the best.
 

RocketRev

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I too thought he was talking about a key switch on either a pad-box or his controller. I was going to recommend the Digikey switch below. Its what we use on our launch controllers. But now its pretty obvious, that he's asking about an avionics switch on the rocket. And that's a very different animal. I'd go with one of the screw switches, but its been so long since I bought one, I don't remember which one to recommend. I use a removable avionics bay that I can move from rocket to rocket. The screw switch is almost indestructible. I got it from some vender like in the late 90's. The removeable avionics bay can hold dozens of different altimeters which means its hard to make obsolete. Anyway, find a good screw terminal switch. They work great.

Brad

CKN11517-ND
 

cls

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Meanwhile, poke the 2 wires out the hole, twist them together, and cover the hole and secure the wire against the air frame with masking tape.

Really. Because I hate all switches, especially those that require a tool to operate.
 

jbr

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depends on the key switch if it is dependable
had one last 10 years in a launch controller before it failed
had 2 in a rocket fail after 20 turns
I will only use screw switches and you don't have to keep track of the keys and which switch they go to
 

Bat-mite

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Meanwhile, poke the 2 wires out the hole, twist them together, and cover the hole and secure the wire against the air frame with masking tape.

Really. Because I hate all switches, especially those that require a tool to operate.
I ordered some from Aerocon. Twist and tuck/tape is the backup plan if they don't arrive in time.
 

Fuddrucker

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I’ve used these on several rockets for years with 100% success. Ordered several times over the years, prices fluctuate anywhere from 1-2$ per switch. All come with 2 keys and all have been keyed alike. There are several sellers on eBay.

Fudd
 

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