Pull Pin Switch: How to Make or Where to Buy

Have seen lots of mention here about pull pin switches but cannot find what I think I want commercially. Does anyone know where to buy them or how to make them? Those I have seen commercially available don't seem to be usable in rocketry.

I use this on my RCRG- When the plug is in the power is off. When it's pulled the power turns on.

https://www.californiasailplanes.com/Powerjack.html

kj

Here' an example from Perfectflite...

https://www.perfectflite.com/StratoLogger manual.pdf

You could probably make one out of brass shim stock. We had something, I can't remember what it was...that used a commercial 1/8" headphone jack, but used a plastic pin instead of a plug. Something like this:
https://www.bgmicro.com/AUD1100.aspx
but in 1/8". When the plastic pin was pulled, the contacts closed, applying power. If you use something like this in a rocket, or build your own, you have to orient the switch to make sure that accelleration won't open/close the contacts by mistake.

didn't these just get banned per the Tripoli rules?


The idea honestly seems a little scary to me to start with, but I have no experience with them.


Braden

They are ok as safety switches for ejection charges. Tripoli has banned the use of pull pins and roller switches for engine ignition (e.g. air starts).

Gary,

The sailplane link is exactly what I use; when not charging, I have a couple blank male plugs with "remove before flight" tags, to keep the system disarmed. I use two per system for redundancy, and a little flair. In the photo, there's a three pin system, one for main power, then one for each system.

Pat

The simplest break wire connectors are made from d-connector crimp-on pin and socket connector inserts shown in the attached drawing. You can get these from any decent electronics supply store. They typically come in strips of 10 or more and cost 10 cents to 25 cents a piece.

You simply simply glue in pairs of pins inside the aft end of the rocket, running wires inside the airframe to the electronics bay. You make a u-shaped shorting wire from 1" length of wire and 2 sockets. Attach a string to the shorting wire and tie it to on of the legs of the launch pad with a little slop. Once the motors ignite, the rocket will lift-off and the shorting wire will stay attached to the pad. The continuity loop is broken to activate a timer or other electronic lift-off detector.

The same concept can be use to detect stage separation or drogue or main parachute compartment separation.

Bob

I am using the same concept but using a 1/8" phone plug (Radio Shack PN 247-248) as a method to activate a audible tracker on my Gizmo. After I built the sled in the nose to hold a BeeLine I started to screw around with what else I could do with it. I put a 9VDC battery on the sled and secured a 90dB Piezo buzzer to the nose bulk plate. The plug will be pulled from the 1/8" normally closed phone jack upon ejection and cause the buzzer to sound until the battery dies. Should make recovery a little easier in the weeds for a total cost of around $7.

gary7 said:

Have seen lots of mention here about pull pin switches but cannot find what I think I want commercially. Does anyone know where to buy them or how to make them? Those I have seen commercially available don't seem to be usable in rocketry.

Click to expand...

You mean one of these??

https://www.gwiz-partners.com/html/g-wiz_mc.html

I'm starting to make these. They use a highly reliable high-current microswitch, and anything 1/8" diameter will work as the pull-pin:

I offer pull pin switch kits in single, double and triple versions. All are operable off a single included pin.

Available here: https://www.labratrocketry.com/shop

Edit: Just realized I followed into a necromancer thread...oh well.

Cl(VII) said:

Edit: Just realized I followed into a necromancer thread...oh well.

Click to expand...

Nice looking products !

In Rocketry, nothing ever dies . . . It just goes "OOP" . . . LOL !

Dave F.

Cl(VII) said:

I offer pull pin switch kits in single, double and triple versions. All are operable off a single included pin.

Available here: https://www.labratrocketry.com/shop

Edit: Just realized I followed into a necromancer thread...oh well.

Click to expand...

I have several and can say from firsthand experience that they are very nice, reasonably priced,reliable and well, orange? I love 'em for anywhere Ya might need or want a pullpin setup.

Necromancer just sounds wrong. Let's maybe ban that word? First amendment be damned!!

gary7 said:

Have seen lots of mention here about pull pin switches but cannot find what I think I want commercially. Does anyone know where to buy them or how to make them? Those I have seen commercially available don't seem to be usable in rocketry.

Click to expand...

Dude, just P.M. LabRat. He'll set you up for less than you could buy and cobble something together..Even includes mounting hardware. Hardest part is drilling that dreaded hole through the switchband with any sort of accuracy. Mine virtually always end up egg shaped.