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In-Flight Disconnecting

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Antares JS

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Hello all, I'm looking for suggestions on some kind of connect/disconnect device to use when running a wire across a separation plane, that allows the wire to disconnect as the rocket body comes apart. Everything I've been able to find seems to lock together in such a way that one has to push or pull on something with their fingers in order to get it apart, and obviously that won't do.
 

Nytrunner

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The red JST (XY?) Connectors have been used as break wires. The plug with the male metal prongs has an outer plastic shroud that covers the female receiver normally, but trimming that shroud back reduces the lock of the connector and they can separate with a tug.

Headphone aux jacks have been used although i think some disfavor those because of how the contacts are arranged

Others use bare metal wire on wire, with a loose wrap that can pull loose.

Ive seen college teams use USB cables as disconnects.
 

Landon

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This is what I did.
 

rocketace

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A few times I have, used standard Molex connectors. The female side was stock but the male side I removed the plastic and it was just the pins which had a good connection yet still pulled out easy. Test fit and then add some heat shrink to any exposed metal to prevent any shorts.
molex.jpg
 

Cesaroni Technologies

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This is what I did.
I did something similar, using BEC connectors. The wire came out of the alt bay and was glued to the side of the rocket down to the separation, where the BEC connector is glued to the top section so that it separates with the rocket, other half of BEC connector glued to bottom section and wire glued to rocket also, running down to the motor.
 

FredA

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I tend to design my electronics so that there is only a signal [not firing current] carried across such a break point.
They I use wire-wrap wire (30-gauge) to bridge that gap.
WW-wire is super easy to break.

Another thought - use wireless -- check the MARSA-NET devices.
 

Dugway

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I've always just used a pair of .1" headers. Never had them come apart before I wanted.
 

cerving

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For my two-stagers, I just run a wire through the bulkplate, tin the end, and wire-wrap the breaking wire twice around the tinned end. I protect the bare ends with two short pieces of 1/8" launch lugs, and tape them together and to the wire on the bulkplate. It works every time.
 
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Antares JS

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I'll have to consider further which one I'm going to actually use, but I appreciate all the options you've given me.

What I'm planning to do is activate a payload in the payload bay in a dual deploy rocket between drogue and main deployment. The main deployment will separate the payload bay though so I need some kind of disconnect in the wire running to the payload bay. I have a Raven 3 so I'm good on setting up the extra event, at least.
 

jnmiller

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I use a magnetic connector, works great!

 

cerving

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I use a magnetic connector, works great!

Wow, that's really cool! They're a bit pricey ($38 for a pair), but it seems like a good solution for larger two-stagers.
 

jmmome

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I was wondering exactly the same thing. I may try holding the ends of bare wires together with heat shrink tubing. But these all are wonderful ideas!
 

OverTheTop

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I use Molex Microfit 3.0 series connectors for this (NC separation). Microfit 3.0 series is positive locking, but the locking mechanism is cut off in this case.


FWIW I make the cable between the central avionics bay and the NC to have the same connectors on each end, with a one to one pin correspondence. That makes it easier and more foolproof when I make replacements. They only last a few flights, but a cheap and easy to replace. A little (lots!) of Electrolube CG53 keeps the BP residue out of the pins reasonably well.
 

Banzai88

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Anyone ever tried male/female breadboard jumpers? They push together/pull apart easily, yet are plenty tight while connected. Cheap, easy, plentiful, sacrificial, cheap......

Amazon breadboard jumpers
 
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icyclops

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Hello all, I'm looking for suggestions on some kind of connect/disconnect device to use when running a wire across a separation plane, that allows the wire to disconnect as the rocket body comes apart. Everything I've been able to find seems to lock together in such a way that one has to push or pull on something with their fingers in order to get it apart, and obviously that won't do.
You said it yourself, everything uses push and pull. How about using “laying against”. A thin ribbon of Adhesive backed copper film/ribbon like your use in hobby dollhouse wiring/electrical may work. Run a piece up the Inside body tube and on the connection point leave a little overhang to touch The top connection. Since it is thin copper metal it can be bent to touch the lower section and at separation there should be little resistance. You could also fold the copper for better contact.
 

icyclops

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You said it yourself, everything uses push and pull. How about using “laying against”. A thin ribbon of Adhesive backed copper film/ribbon like your use in hobby dollhouse wiring/electrical may work. Run a piece up the Inside body tube and on the connection point leave a little overhang to touch The top connection. Since it is thin copper metal it can be bent to touch the lower section and at separation there should be little resistance. You could also fold the copper for better contact.
or run it down and then outside of a coupler that touches the inside copper film running on the inside of the lower body tube.
 

QFactor

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Anyone ever tried male/female breadboard jumpers? They push together/pull apart easily, yet are plenty tight while connected. Cheap, easy, plentiful, sacrificial, cheap......

Amazon breadboard jumpers
That sounds like a good suggestion. I have a pile of them for my electronic projects. They hold firm, but are still easy to pull apart.
 

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I have done this quite successfully with RCA connectors. In my more complex project that required power and signal I used a snug fitting thread together multipin plastic connector and removed the nut from one side. This worked very well, here is a link to the manufacturer page:


One benefit of these over deans and jumpers is they are guided as they slide out so even if they pull at a bit of an angle the pins can't be bent or jam.
 
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