Pull Pin Switch: How to Make or Where to Buy

Discussion in 'Rocketry Electronics and Software' started by gary7, Mar 1, 2012.

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  1. Mar 1, 2012 #1

    gary7

    gary7

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    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.
     
    Last edited: Mar 1, 2012
  2. Mar 1, 2012 #2

    kjohnson

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  3. Mar 1, 2012 #3

    Worsaer

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  4. Mar 4, 2012 #4

    Sooner Boomer

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    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:
    http://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.
     
  5. Mar 4, 2012 #5

    UPscaler

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    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
     
  6. Mar 4, 2012 #6

    Worsaer

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    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).
     
  7. Mar 11, 2012 #7

    Blackfly

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    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

    Pull pins.jpg
     
  8. Mar 12, 2012 #8

    bobkrech

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    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

    d-conn crimp pin and socket .jpg
     
  9. Mar 15, 2012 #9

    Disaster_Guy

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    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.
     
  10. Mar 26, 2012 #10

    neond7

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    You mean one of these??

    http://www.gwiz-partners.com/html/g-wiz_mc.html
     
  11. Nov 21, 2019 #11

    skydog

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    2019-10-27 15.33.11 (Medium).jpg 2019-10-27 15.33.22 (Medium) (1).jpg 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:
     
  12. Nov 21, 2019 #12

    Cl(VII)

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    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.
     
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  13. Nov 22, 2019 #13

    Ez2cDave

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    Nice looking products !

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

    Dave F.
     
  14. Nov 22, 2019 #14

    Wallace

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    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.
     
  15. Nov 22, 2019 #15

    Wallace

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    Necromancer just sounds wrong. Let's maybe ban that word? First amendment be damned!!
     
  16. Nov 22, 2019 #16

    Wallace

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    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.
     
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