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mo2872

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So I'm building my first DD rocket, a Composite Warehouse Ibex 54. It's time to start getting serious about the recovery.

So far I have a Missile Works RRC2+ altimeter, and their corresponding sled, but I have newb questions I can't seem to quite find answers to. Thus, I consult the TRF brain trust.

1. When using "glove tips" as ejection charge holders, how do you close them up? Pictures anyone?
2. Same topic, how then, do the tips get mounted to the avbay bulkheads? Pictures?
3. Can you use the QuickDip pyrogen as ejection charge ignition, or are they just for motors??
4. When your airframe is only 54mm, it doesn't leave a lot of room on the bulkhead for wire connections....best to just drill holes for the wires to pass directly through, and seal with poster putty/something?

Thanks, all!!

Pics attached for where I am right now.......and a fun little pyro video I made last night trying my hand at an ejection charge test. Taped up a little Triple Seven with an Estes ignitor.......fun times! LOL
 

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Nytrunner

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1. When using "glove tips" as ejection charge holders, how do you close them up? Pictures anyone?
2. Same topic, how then, do the tips get mounted to the avbay bulkheads? Pictures?
3. Can you use the QuickDip pyrogen as ejection charge ignition, or are they just for motors??
4. When your airframe is only 54mm, it doesn't leave a lot of room on the bulkhead for wire connections....best to just drill holes for the wires to pass directly through, and seal with poster putty/something?
1- Powder in the tip, match/igniter in the middle of the powder, tie off the little baggy (as little extra air as possible), trim extra, secure with tape or rubber band as desired. Some jsut use masking tape packets to hold the powder [I prefer a more rigid containment system like a pipe cap or empty cartridge]

2- Those that use glove tips often leave them loose. Either directly next to the ebay bulkhead, or on wire extensions to position them so they're better position to eject the chute (instead of pushing chute into airframe and letting separation pull it out.

3- I'm not sure what you're asking here, or what you want to augment with the pyrogen. Any e-match should be able to light a powder ejection charge without augment. (estes igniters are not great for this application)

4- That's what I do. Wire through, putty the gap.
 

mo2872

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Thank you for the reply.....

On 3, I'm specifically asking if I can make my own charge igniters with the QuickDip kit? Sounds like that is a yes. I only used the Estes one last night because that is what I had on hand, and, well........any chance to turn things into smoke and fire, right??
 

Banzai88

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On 3, THIS is what you want.

Apogee ejection is the single most critical phase of the flight safety wise.
 

Nytrunner

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Ah! Now i get you. You can definitely make a very small one for use as a charge lighter, but test them thoroughly to male sure they light relatively quickly.

Ill admit that did look like a surprisongly good poof using an estes igniter
 

dvdsnyd

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Quick dip is mostly used for starting motors with a bridgewire arrangement. These as well as the Estes igniters tend to require more power to ignite reliably. Not making them suitable for dual deployment. Most, if not all of us use some type of e-match for electronic deployment charge activation. I use MJG firewire initiators, and have really good success. There are likely others on the market. The documentation for your altimeter will likely provide you with some insight on what to use too. The nice thing about the firewire is that it is not regulated by the ATF.

MJG Firewire
 

Kelly

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Making your own igniters is fine for starting the first stage of any rocket, where the consequence of a failure is walking out to the pad and inserting a new one. When it's necessary to prevent a dangerous ballistic recovery, you need something with proven reliability. You could make your own, but you'd need to have very tight controls over your manufacturing process, do LOTS of testing and statistical analysis, etc. etc. to be confident of reliability. Easier to buy one.
 

mo2872

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Making your own igniters is fine for starting the first stage of any rocket, where the consequence of a failure is walking out to the pad and inserting a new one. When it's necessary to prevent a dangerous ballistic recovery, you need something with proven reliability. You could make your own, but you'd need to have very tight controls over your manufacturing process, do LOTS of testing and statistical analysis, etc. etc. to be confident of reliability. Easier to buy one.
That's a good point, thank you. For the sake of sizing my charges, probably fine to use the readily/locally procurable Estes igniter like in the video above......at least until time to vac test the altimeter, anyway!

Thanks!
 

OKTurbo

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Todd,

You'll want to use e-matches. They take very little current to light off. And it's going into black powder so it doesn't take much to make it go.

I make my ejection charges using glove tips. I think I have a youtube video showing how I do it.

You're welcome to come over to the OKTurbo shop and I'll help you get it set up.

John
 

Jmhepworth

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When I use glove tips, this is what I do:

1. Cut the glove tip to about 1 inch.

2. Measure the powder and poor it into the glove tip.

3. Insert the e-match.

4. Tie off the glove tip with string, compressing everything into the tip as best I can.

5. Wrap the glove tip above the powder with green tape, covering the string up to the wire on the e-match.

6. Write the amount of powder on the tape with a pen.

I‘ve found that tape alone isn‘t tight enough to contain the powder; nor is string by itself. The two together seems to work. I use green tape rather than blue because it’s stickier. I write the amount of powder in the charge because I generally add 50% to the backup charge and I don’t want to confuse them When I attach them to the altimeter.
 

mo2872

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Todd,

You'll want to use e-matches. They take very little current to light off. And it's going into black powder so it doesn't take much to make it go.

I make my ejection charges using glove tips. I think I have a youtube video showing how I do it.

You're welcome to come over to the OKTurbo shop and I'll help you get it set up.

John
Hmmm, may have to take you up on that, you're not that far from C-ville! Thanks!
 

OKTurbo

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Hmmm, may have to take you up on that, you're not that far from C-ville! Thanks!
I’m off work all next week. Need to use up my vacation days before the end of the year.
 

wsume99

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That's a good point, thank you. For the sake of sizing my charges, probably fine to use the readily/locally procurable Estes igniter like in the video above......at least until time to vac test the altimeter, anyway!
It's not clear but I think you plan use Estes igniters for ground testing to get your charges sized properly? I would not recommend doing that. You want to ground test with whatever you are going to use in flight. If you change anything, ground test it again before flying that configuration.
 

OKTurbo

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Here’s a video showing how I make my ejection charges. Fast forward to 13:00 to get past the other stuff.
 

mo2872

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It's not clear but I think you plan use Estes igniters for ground testing to get your charges sized properly? I would not recommend doing that. You want to ground test with whatever you are going to use in flight. If you change anything, ground test it again before flying that configuration.
Oh, will definitely test with e-matches as well, when I can get some here. The Estes thing is really just to see how to make it work.

I was thinking of ordering this kit from Apogee....any thoughts?
https://www.apogeerockets.com/Rocket-Motors/Motor-Starters/E-match-Starter-Kit

Says for starters or dual deployment uses....?
 

Banzai88

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Oh, will definitely test with e-matches as well, when I can get some here. The Estes thing is really just to see how to make it work.

I was thinking of ordering this kit from Apogee....any thoughts?
https://www.apogeerockets.com/Rocket-Motors/Motor-Starters/E-match-Starter-Kit

Says for starters or dual deployment uses....?
Again, results are highly dependent on user technique. Apogee ejection/airframe seperation is the single most important phase of a dual deploy flight from a safety perspective.

Stay safe and use commercial ematches for flight.
 

wsume99

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Oh, will definitely test with e-matches as well, when I can get some here. The Estes thing is really just to see how to make it work.

I was thinking of ordering this kit from Apogee....any thoughts?
https://www.apogeerockets.com/Rocket-Motors/Motor-Starters/E-match-Starter-Kit

Says for starters or dual deployment uses....?
Copy on the Estes igniters. No reason you cannot use them to practice as long as you ground test with the flight hardware once you have it.

RE: that kit from Apogee. I would just order ematches if I was in your position. All you need is an ematch for deployment. Two popular options are MJG or Bilusocn. So just buy them ready to go instead of having to make them. Making them adds another potential source of variation and failure that you don't need when first starting electronic deployment IMO. In a real pinch I've seen ematches be used as igniters for HPR motors. It's not a sure thing but it can work. Making your own igniters is a lot lower risk IMO because if they don't light you just shove another one in the motor and try again. If your ematch fails on electronic deployment that's an entirely different situation.

EDIT - Here's the premade ematch you want from MJG. 80 pcs of either the 1ft or7ft length would be less expensive than the kit from Apogee and you don't have to apply the pyrogen.
 
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mo2872

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Copy on the Estes igniters. No reason you cannot use them to practice as long as you ground test with the flight hardware once you have it.

RE: that kit from Apogee. I would just order ematches if I was in your position. All you need is an ematch for deployment. Two popular options are MJG or Bilusocn. So just buy them ready to go instead of having to make them. Making them adds another potential source of variation and failure that you don't need when first starting electronic deployment IMO. In a real pinch I've seen ematches be used as igniters for HPR motors. It's not a sure thing but it can work. Making your own igniters is a lot lower risk IMO because if they don't light you just shove another one in the motor and try again. If your ematch fails on electronic deployment that's an entirely different situation.

EDIT - Here's the premade ematch you want from MJG. 80 pcs of either the 1ft or7ft length would be less expensive than the kit from Apogee and you don't have to apply the pyrogen.
😳. Now that’s great right there. My cheap was showing with looking at the DIY kits, but those you linked are a steal. Order placed! Thanks!
 

shawn_rocket

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I have used these ignitors/e-matches with no issues.


Someone here on TRF recommended them, and in the many tests I've done, no failures. When I put them in for a flight, I'll check continuity and resistance to make sure they are good.
 

shockie

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Would somebody bring me up to date on the status of using BP for ejection charges? Has everybody changed over to confined smokeless powder instead? What's the good old boys at the BATFE saying about these days? TIA

TD
 

Banzai88

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Would somebody bring me up to date on the status of using BP for ejection charges? Has everybody changed over to confined smokeless powder instead? What's the good old boys at the BATFE saying about these days? TIA

TD
Almost no one is using smokeless powder or BP substitutes. I'd say 99.5% of the community is using 3F or 4F black powder.

Those that do experiment with smokeless powder have very tortured routines to make it work and have a long, inconsistent development path. Users are rare, and reliable deployments even more so. Reported results and techniques are either poorly documented and/or difficult to replicate for other users.

Exploring the use of BP substitutes seems to be more common place. Users are infrequent, and all seem to agree that TIGHT, CONSISTENT confinement is the key to success. Reliable deployments are.........a mixed bag of reports. Reported results and techniques are rather well documented and, with some individual development, relatively consistent for other users to replicate.

A pound of BP is probably an average rocket flyer's lifetime supply. It's well understood, easy to use, has repeatable results, is dead flat reliable, and easy and cheap enough to acquire if you get past the paradigm of "EVERYTHING I WANT SHOULD BE ON EVERY STREET CORNER STORE 24/7/365 AND ANYTHING THAT ISN'T THAT WAY IS B.S. AND I'M NOT GOING TO TRY"

People pay rocket motor shipping and hazmat and burn $100+ motors for 3 minutes of fun.......and they're usually the ones that don't have or simply won't go to a local gun shop that carries BP and are complaining about hazmat for a LIFETIME supply for 1 pound of black powder.
 
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firemanup

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I do it the same way as okturbo, minor changes i use a powder funnel from measurement device into glove tip, and i use electrical tape instead of masking tape.

I then put the charge into a charge well.
 

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I use 4F with 3D printed canisters. I have printed 1gm scoops and funnels to go with them.
 
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