Where are you placing them? Below sustainer motor in the transition coupler? Does it take much BP to separate? Would you fire it from alt in booster?
separation charge
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For my 2 stager, I just pack 4F BP into the red cap that comes with the MJG Firewires and tape it up. I run the wires for that and the ignitor down thru a tube in the sustainer. I Gorilla Tape the ignitor in place and then the loaded red cap (sep charge) just rests on the tape. Has worked great from observing the onboard video on the sustainer looking down. (I was never able to get drag separation which can get your ISC crispy although I did paint the interior of it with Hi-Temp paint and stuff it with wadding.)
I use less than a half gram in a glove tip. I run the wire through a hole in the interstage coupler and set it off from the interstage coupler (on the booster side). I typically use the aux port in an RCC3 or one of the ports in an Eggtimer Quantum and set the timer for about half a second after motor burn out. You want to dump the booster as soon as you can after burnout. If I use an RRC3, I use both ejection charges at apogee and apogee +1, as well as motor backup. If I use a Quantum, I deploy at apogee and use motor backup.
Yes, below sustainer motor in the coupler. I use 0.5g glove charge. I fire from booster on one and sustainer on another.
waltr
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Same here, 0.4gm inside the ISC on a 3" diameter rocket.
Using an Eggtimer Proton and firing at 0.1sec after booster burn out.
Using an Eggtimer Proton and firing at 0.1sec after booster burn out.
MClark
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I will put a thin disc of ply or G10 over the nozzle so separating charge won’t put fire into the motor. Hold in place with tape.
Typically I wire the separation charge with the sustainer ignition.
Typically I wire the separation charge with the sustainer ignition.
How do you wire charge with ignition? Separate output on alt? or same output with wires in parallel?
Also how do you lengthen ignitor wiring to sustainer motor? I will fly AT motors, I use MJG ematches for BP charges, but don't think they will work to ignite motor. I installed a brass tube past MMT for wiring. It is 1/4" wide by 3/32" tall. The ematch wires fit through easily.
Also how do you lengthen ignitor wiring to sustainer motor? I will fly AT motors, I use MJG ematches for BP charges, but don't think they will work to ignite motor. I installed a brass tube past MMT for wiring. It is 1/4" wide by 3/32" tall. The ematch wires fit through easily.
Titan II
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I do the same using same output. Parallel. Just extend with shooter wire.
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MClark
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Wired parallel.
To lengthen wires I solder wire of a similar size. Stranded is better than the solid wire on matches.
With minimum diameter I will use more electronics in the stage coupler.
I usually use Davy fire with something to boost ignition
To lengthen wires I solder wire of a similar size. Stranded is better than the solid wire on matches.
With minimum diameter I will use more electronics in the stage coupler.
I usually use Davy fire with something to boost ignition
MClark
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I never depend on drag separation. But if using electronics in coupler and worried it may happen I have it so the electronics go with upper.
Do you pin the sustainer into the ISC?
I searched Davy fire and came up with just fireworks. Do you have a link? Thanks.
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Nope. Slip-fit.
Note that separation charges are a "nice to have", but not essential. If drag doesn't separate your stages, the sustainer motor ignition will. It may toast the insides of your ISC slightly, however... but I've never had a serious issue with that.
Titan II
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Charles_McG
Ciderwright
Like others above, I pack the red ematch cap with BP and tape it over. That’s for 1.5” to about 2.7” diameter. The 5.5” Talos to 3.1” Terrier interstage took a slightly bigger charge that I put in the cap for the little tiny between-tooth brushes. A paper tube extension to the red cap would work as well, I bet.
I use the orange ematch wire, or color coded CAT 5 or 6 wires in 1/8” OD plastic chem tubing. A pair of tubes wrapped in Aluminum tape - keeps the pair together and turns them into a stick that’s easier to run through holes in centering rings. Above the last centering ring, I Al tape them to the inside of the body to help keep them out of the way of the recovery goodies. I once used flat speaker ghost wire in a tight space - but found it hard to connect to other wires- and fragile to bending. The two pairs of wires are 180° apart in the airframe, and get separate pyro channels on the Proton.
I let the separation charge dangle under the sustainer motor - which usually has a cap, or tape over it. I fire the sep charge at burnout+0.2sec, and the sustainer at burnout +0.7sec. I used to do a slightly shorter coast - but the Proton baro data shows some big swings with the sep charge and a little longer coast allows it to settle down.
I use the orange ematch wire, or color coded CAT 5 or 6 wires in 1/8” OD plastic chem tubing. A pair of tubes wrapped in Aluminum tape - keeps the pair together and turns them into a stick that’s easier to run through holes in centering rings. Above the last centering ring, I Al tape them to the inside of the body to help keep them out of the way of the recovery goodies. I once used flat speaker ghost wire in a tight space - but found it hard to connect to other wires- and fragile to bending. The two pairs of wires are 180° apart in the airframe, and get separate pyro channels on the Proton.
I let the separation charge dangle under the sustainer motor - which usually has a cap, or tape over it. I fire the sep charge at burnout+0.2sec, and the sustainer at burnout +0.7sec. I used to do a slightly shorter coast - but the Proton baro data shows some big swings with the sep charge and a little longer coast allows it to settle down.
I don’t and have never seen anyone else do it but that’s not to say it can’t be done. Not sure why you want to.
i can't find them in a search. Are they still made?
Titan II
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I have seen others do it for a variety of reasons.
I pin all separation points on all my rockets. It keeps everything aligned and holds everything together. I transport rockets intact. Nothing can shift or slide apart.
Another point. Some people light the sustainer from the ISC. You sure do not want drag separation at booster shutdown before you light the sustainer.
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I use 2 separate 2 wire leads thru my cardboard tube in the sustainer. Be careful with running through the brass tube so you don't create a short. I use a Proton in the sustainer. One pair is to a channel for the sep charge which I set at 0.6s after burnout. The other pair is connected to another Proton channel for sustainer ignition, that I've set at about 1.2s after BO. At the pad when I insert the ignitor in the sustainer, I then wire wrap the ignitor wires to the pair of wires that I had run down the tube. I tape those to prevent a short. As I stated above, I then use Gorilla Tape to hold the ignitor in place and then fold over the sep charge in the taped red cap. Mostly I use CTI motors in the sustainer and AT or CTI in the booster. The CTI's light easier due to their "pellet", otherwise you need to enhance the pyrogen to airstart an AT.
MClark
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I got many Davyfires and Atlas M100 many years ago.
No idea where to get them.
pin, no
I use various propellants for the ignitor. BP and Pyrodex burn at low temp compared to an aluminized prop.
No idea where to get them.
pin, no
I use various propellants for the ignitor. BP and Pyrodex burn at low temp compared to an aluminized prop.
Makes sense
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So, separation charge and sustainer ignition are on the same output channel of the altimeter? Interesting. Is this based on the fact that sustainer motor takes a few seconds to come up to pressure, and by that time the booster will have been blown off?
Titan II
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Yes. This is not the best way to do it if you are looking for maximum altitude as the booster is tagging along longer than absolutly necessary. However, that is not an interest of mine at this time and it has worked well 100% of the time.
No, but I do pin the ebay in the sustainer to the aft airframe to make sure I don't get any drag separation in the sustainer. Nose cone is pinned as well of course.
MClark
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Yes.
I see no reason to pin the interstage coupler to the sustainer. Nothing good can come from it. It won‘t separate as long as the booster is under thrust, and you want it to separate as soon as possible after booster burnout. Pinning it does nothing useful and might be harmful If it delays separation.
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And if for some reason it doesn't completely separate... that will be bad. No pins.
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