Very nice. How do you hook up the matches to the charge? What are you using to secure match and charge in the well?
Dual Deploy
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rharshberger
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Here is a link to a review I did of the 38mm SMT bay for my Rabid Weasel https://www.rocketryforum.com/threads/smt-designs-38mm-bay.148001/
The charge holders mount to the coupling nuts (threaded standoffs in center of cap) and one ematch wire is actually wrapped around the screw protruding from bottom of charge well, the other wire attaches to another screw type terminal on the bulkhead of the Av-Bay.
both binding post can be seen in this picture.
Most of my AvBays that are my own designs us a well nut to pass the wire for the ematch through the bulkhead and the ematch is connected directly to the altimeter (fewer connections to create a failure point) and look something like the one below which is for a fiberglass Madcow Mini-Frenzy XL 1.6" (38mm).
Well nut (rubber flange expansion nut for pass through of wire, the I use a small file and slot the edge of the hole for the wire), charge well is a piece of .223 REM/5.56 NATO brass cut down.
Assembled bay.
38mm bay, everything is really tight....
Picture of bay with one bulkhead attached, showing bottom of well nut on bulkhead bay. Well nuts seal the bulkhead pass through and have worked very well for me and have been used on nearly all of my builds.
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what are you using to keep powder in the charge well?
rharshberger
Well-Known Member
Masking Tape (off white full strength type, not blue or green) with dogbarf as a over powder wad.
Exactly!
rharshberger
Well-Known Member
A wise senior rocketeer once told me not to use the blue or green masking tape for anything important (friction fitting airframe couplers was okay though), as it might not hold well enough during acceleration/deceleration and the ejection charges are probably the most important thing to keep secure.
How tightly do you stuff the barf in? I have my 1st AV bay aet up with .44 mag casing as the charge wells. I just emailed eggtimer to purchase a Quark and a Quantum. What are good ematches to use? What is normal, seperate at the NC to payload tube joint, or the coupler to bottom of payload tube. Is there anything wrong with using motor eject at apogee for the drouge?
rharshberger
Well-Known Member
I like the dog barf packed as tightly as I can get it using a dowel and hand pressure only. MJG Firewires are a good, legal, easy to get ematch.
I use motor deploy as a back up if I can on DD flights, as for separation locations for the airframe I usually use nose cone for main, the drogue is dependant on whether or not I built it zipperless.
I use motor deploy as a back up if I can on DD flights, as for separation locations for the airframe I usually use nose cone for main, the drogue is dependant on whether or not I built it zipperless.
Thanks, if I seat a bullet to deep it will cause an over pressure in the case and bulge it. Not that I am worried about a cse bulge with this small amount of BP, but do not want to blow the tube apart.
That’s not a concern with black powder and dog barf filler. We’re not sealing the case. The dog barf isn’t as tight or solid as a bullet. And black powder burns differently than smokeless powder.
I use a disposable foam earplug pushed into a centrifuge tube. I push it in with the eraser end of a pencil until it’s tight against the BP. The earplug expands to hold it in snugly. I add some blue tape over the opening of the downward-facing charges just in case.
rharshberger
Well-Known Member
Are the earplugs biodegradable? I am not an enviro loony but common disposable ear plugs are not, if they are then thats another good method for over powder wads.
Out of curiosity, and not with the intention of starting a urination match, seriously wondering ...
Have you ever fired a BP cartridge? BP behaves very differently from smokeless...
To be clear, coming from a purely smokeless background, this is a good question, but, as Steve said upthread, BP behaves differently from smokeless.
Nope, never fired BP. Gotta learn!
It's totally different from that new-fangled smokey-less powder. Especially in cartridges. 
Actually, come to think of it, with all the pounds of 3F I've burned, I've never fired a muzzleloader.
But, yeah, as others have stated, you aren't going to blow anything up by compressing it.
Actually, come to think of it, with all the pounds of 3F I've burned, I've never fired a muzzleloader.
But, yeah, as others have stated, you aren't going to blow anything up by compressing it.
I have shot muzzle loaders before, both pellets and loose powder. Not lots though. I reload with Hodgen H110 in .44 mag rounds, 30.9 grains will push a 180 grain slug over 1000ft/s. Still have to purchase ffffg powder. Online, all I have found requires 5 lb min order, can't see the need for that much.
rharshberger
Well-Known Member
Get with other members of your club and make a group buy.
Good suggestion.
Another idea, since you mention that you reload smokeless: order some powder from a good online supplier. I've been ordering from Graf & Sons for 10+ years; the minimum powder order is 4 pounds, but you could buy 3 pounds of smokeless and one pound of black. (I have no affiliation with them other than as a long-time satisfied customer).
As a bonus, the "house" brand burns cleaner and costs less than Goex, which is the only thing you're likely to find locally, if you can find anything at all. Not that "clean-burning" is as important in a charge well as it is in a barrel.
Apogee has those E-Match mates that work really well for smaller diameter rockets if you are looking for a bulk head mount. Seals and holds E-match to bulkhead and re-usable silicon cap holds powder. Cost is more than gun brass, but simple may be worth something...
I use 3f powder I picked up at Cabela's. I have used it compressed in pvc cap charge wells or "loose" in a plastic bad with some ematches with good luck so far.
Ground testing for everything matching as many flight parameters as possible, just to make sure.
~John
Ground testing for everything matching as many flight parameters as possible, just to make sure.
~John
My kid found me some fff powder last night at cabelas, will try that. But after depolmyent how do you keep all the parts from banging into each other> The Black Hole EXT will have a 24", plus NC, payload section dangling under the chute, along with booster and AV bay.
Planning on ground test. Have e match kit coming from MJG.
What is a cable cutter?
What is a cable cutter?
Titan II
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Yup had found video, but would not the JLCR be a lot easier?
JLCR is definitely a lot easier. Cable-cutters need BP and constant cleaning. It is hard to find the right size cable ties, and cutters have essentially become obsolete.
I still have one, but haven't used it in years.
grouch
Well-Known Member
I gave my cable cutter away years ago. It worked but it was fiddely. It was also a pain in the butt to clean. I like clean so no like cutter.
Cory
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I
[url=https://www.flickr.com/photos/98606523@N08/]
How tight are your couplers in the tubes?
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2 fold answer:
1. Cardboard. Tight enough to be able to pick up the fully prepped and ready to fly rocket without it separating any more than 1/3 of the engagement length. IF I'm using shear pins, a little looser, and the shear pins go in. With this guidance, whatever the temperature or humidity, I never get something too loose or too tight.
2. Fiberglass. I usually have a really tight tolerance fit, as in pulls a vacuum close, but pulls smooth as an oil slick bowling lane. I usually use 1 strip of good masking tape, and one or more shear pins in the same manner as cardboard.
Ground Test, Ground Test, Ground Test.
It's amazing how many DD questions can be answered by ground testing, isn't it?
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