Richtee Posted June 17, 2009 Posted June 17, 2009 a small steel piston nested in a plate. The comp is placed under the piston, and the dropped steel strikes the piston rather than the comp itself. Sounds like N Korean missile testing to me ;{)
Rogue Chemist Posted June 17, 2009 Posted June 17, 2009 The "target" could be made very fancy; a small steel piston nested in a plate. The comp is placed under the piston, and the dropped steel strikes the piston rather than the comp itself. I think it'd be more consistent that wa That's how commercial drop/fall hammer test machines are made. 2 small pistons that fit perfectly into a small thick-walled metal cylinder. The weight is then dropped on it from various heights to give impact sensitivity in joules.
Swede Posted June 17, 2009 Posted June 17, 2009 (edited) I decided to try egg crate fluorescent light cover material to create stars. I know it's been done, but I think I came up with an idea or two that might come in handy, specifically the misting and smoothing of the individual cell surfaces before allowing the cells to partially dry for extraction, and the use of a rectangular "poker" to eject the individual stars, which otherwise would be a bit tricky to remove. Summary - it works. Faster than pumped, and for me, at least, better and more consistent than cut. Rather than do a tutorial, I threw it up as a blog entry. Egg Crate Stars http://www.5bears.com/firew/egg06.jpg http://www.5bears.com/firew/egg13.jpg Let me know what you think. Edited June 18, 2009 by Swede
50AE Posted June 17, 2009 Posted June 17, 2009 Good job for the tutorial. I have to give it a try too. ...but I can't find an "egg crate", I'm keeping searching though. I'm also wondering if there are some with smaller squares, because 1/2" seems big to use for small shells.
Swede Posted June 18, 2009 Posted June 18, 2009 The rectangles are 3/8" thick or smaller. For charcoal streamers, at least, I think they'll be OK for 3" cannister or larger. But I agree, a 3/8" X 3/8" x 3/8" would be very nice. 1/4" square would be pretty tedious to extract from the egg crate. I think we can look at egg crate as a poor-man's star plate. It really did seem to work well.
qwezxc12 Posted June 18, 2009 Posted June 18, 2009 Swede, Excellent tut... I'll admit to 'liberating' a fluorescent light diffuser from a men's room a while ago to try the same. I never got it to work to my satisfaction... looking at your method leads me to the opinion that I did not use enough water/alc or perhaps I didn't consolidate the stars enough...I'll up the % as if I were cutting and see if the stars retain the integrity that they need to be ejected in one piece. Thanks for the kick in the pants...
Mumbles Posted June 18, 2009 Posted June 18, 2009 I've made a few light diffuser stars. They definitely have to be wet to the level of cut stars to get them to get hard enough IMO. I eject them after 24 hours. They're wet enough to flex while ejecting, yet dry hard as rocks. I also use SGRS usually.
Bonny Posted June 18, 2009 Posted June 18, 2009 Great Tutorial Swede. I have done stars almost the same as you on many occasions, using my hand to consolidate. I also use fingers on each cell individually (mostly around the edges). I've found with Tigertail and several other comps , that once dry, the stars are falling out on their own...sometimes needing only a little push with a finger. Maybe my egg crate/light diffuser has more of a taper??Anyway, as you said, a great way to quickly make batches of consistently sized stars.
Swede Posted June 18, 2009 Posted June 18, 2009 Thanks guys, and the comments were right on. This batch is about 90% dry (it's hot here) and I've noticed that the stars that are less dense (those that were not packed as much as others) are not physically as strong as the better stars. These whimpy stars total about 10% of this test run. So the methodology must be one that compresses the comp as much as practical. The heel of the palm thing did work, and the best stars came from the areas that were heaped high with comp and then really massaged down, with the excess comp flowing to the side. A touch more binder and water or alcohol will also be helpful. SGRS is probably better than dextrin. Red gum, I don't know, but I suspect it would work well with egg crate stars. Alcohol should be fine on the plastic. More thoughts... a sheet of thin brass or even stiff plastic or cardboard could mask portions of the eggcrate while massaging the comp in. Excess comp flows onto the sheet, which is then moved, and the comp gathered on it is dumped into the now opened cells. Or, one could have a thicker metal plate, preferably aluminum, heap the comp thick onto the egg crate, lay the plate on top, and tap it in (maybe even press it) with a rubber mallet. Or skip the plate entirely, just wail away with a rubber mallet onto heaped comp. I had also meant to dust the egg crate with graphite, which might help a little with the extraction. My egg crate has zero taper; those WITH taper are golden. I also need to try drying it longer. A day or more of drying should see the stars contract more and also be stronger, allowing serious manipulation of the egg crate to get them to fall free. The best part, the stuff is very cheap. A 2' X 4' section is just a few bucks, and I've seen it in trash cans many times, because they break, and people throw them away.
Ventsi Posted June 20, 2009 Posted June 20, 2009 Haha... My mom just gave two picture perfect 1-7/8" mortars that she grabbed from her work. 11" tall1/4" walls!!These should last forever and if I get bored of them they would make great salute casings!
swervedriver Posted June 21, 2009 Posted June 21, 2009 Haha... My mom just gave two picture perfect 1-7/8" mortars that she grabbed from her work. Don't you love when you get good pyro stuff for free? I got these from a customer the other day.They're 1.5" thick walled tubes. I'm making a re-useable mine cake, they're cut, treated, and plugged. This will last for a long time-
flying fish Posted June 21, 2009 Posted June 21, 2009 Not enough time for the 4th! And I don't have enough stars made!!! I don't live at my place of building during the week (and I'm away this weekend and next), so you can see how time is running out for me. I'm thinking I need something REALLY simple & easy that I can make a lot without needing to trouble shoot things...annoying issues like priming and fallout reduction. Perhaps I'll just use some BP and aluminum. All I'd need is a bunch of low-grade meal powder and dump in some aluminum. Maybe around 10% Al (so I guess that's reeper's silver). And I'll make some of the other fairly easy things that I normally do... a couple of different glitters and C6.
Ventsi Posted June 22, 2009 Posted June 22, 2009 I can beat that. I got a 3'' mortar and one uncut tube which I sliced into 5-1" SUPER HEAVY WALL[5/16] tubes for free from the next to the dumpster behind my local post office. But yeah I was real psyched about the mortars, just because I was meaning to buy some for so long ... There OTC pyro stuff out there we just have to find it:
swervedriver Posted June 22, 2009 Posted June 22, 2009 Not enough time for the 4th! And I don't have enough stars made!!! I don't live at my place of building during the week (and I'm away this weekend and next), so you can see how time is running out for me. I'm thinking I need something REALLY simple & easy that I can make a lot without needing to trouble shoot things...annoying issues like priming and fallout reduction. Perhaps I'll just use some BP and aluminum. All I'd need is a bunch of low-grade meal powder and dump in some aluminum. Maybe around 10% Al (so I guess that's reeper's silver). And I'll make some of the other fairly easy things that I normally do... a couple of different glitters and C6. Not sure why, but another benefit of adding metal to charcoal streamer comps is that the stars dry faster too. 3/8" stars should be dry in time for you to build some stuff by the 4th!
Swede Posted June 22, 2009 Posted June 22, 2009 My 3/8" X 1/2" charcoal streamer egg-crate stars were dry in 3 days, but admittedly that is in the Texas shade, 90+ degrees. I think the absolute fastest way to dry without heat is to place the stars on a screen and get a good fan going over them. The moving air helps tremendously. One thing to watch out for is to dry the star's outside TOO fast, forming a dry, impermeable skin and a locked out, damp core. I think that's more common with colored comps, though. Just like last year, I'm kicking myself in the a$$ for not doing more. Typical time-crunch scenario. All I want to do are a few 3" cannisters and a few rockets, nothing big. I've got some 65:25:10 BP rocket fuel milled, still need to make a bit of whistle for the cannister shells, maybe some KP too. I was thinking riced 4:1 KP and a dash of "Mrs. Whistle" for the 3" plastic cannisters - sound good?
flying fish Posted June 23, 2009 Posted June 23, 2009 (edited) Not sure why, but another benefit of adding metal to charcoal streamer comps is that the stars dry faster too. 3/8" stars should be dry in time for you to build some stuff by the 4th! I think many metal powders are hydrophobic...either naturally and/or because they have some kind of coating on them. I wonder if that helps drive away the water... Luckily, it looks like I've got all of tonight to work on star making, and probably some of friday night (after I'm done packing for a camping trip). While I'm away, I'll whip up a batch of NC laquer, bring it back home, and use that for whatever stars still need to be made at the last minute. Gosh, I should get something in the mill strait away!!! I had jury duty today. SOOO happy I didn't get picked. Obviously no desire on going back there. 'specially as it's nearing my school term. Basically I've got two weeks to attend two family vacations, write 1 thesis, prepare for organic chemistry so it doesn't kick my ass, and prepare for the 4th of July, all while working more than full time at a place where I have an obligation to wrap up various projects and document the hell out of everything!!! That's my "summer break" for you. Edited June 23, 2009 by flying fish
TrueBluePyro Posted June 24, 2009 Posted June 24, 2009 (edited) TurboPyro did anyone buy one or have a look at it, it looks really great for begginers, I would buy one if I was in the US and just starting out. The 400 copies that skylighter relesed of this thing got sold out in in less then 2 hours. It must be good. MODERATOR EDIT: No posting of copyrighted materials without an explicit release from the copyright holder.If you can provide proof that this was released to the Public Domain, then you may repost the attachment. Thank you. Edited June 24, 2009 by TheSidewinder Removed attachment
Richtee Posted June 24, 2009 Posted June 24, 2009 Detroit fireworks tonight. Reported a few more than 10,000 shells to be launched. Wow. I'm deciding if I can watch or not. Sigh.
Pretty green flame Posted June 24, 2009 Posted June 24, 2009 Detroit fireworks tonight. Reported a few more than 10,000 shells to be launched. Wow. I'm deciding if I can watch or not. Sigh. What's there to decide
TrueBluePyro Posted June 24, 2009 Posted June 24, 2009 Oh yeah Sidewinder, It is free everyone is allowed to download it, I downloaded it from skylighter, I am trying to find the link I got it from but I did download it leglly, so it is ok to post here, but I will find the link again and then you guys can download it from there I guess.
TrueBluePyro Posted June 24, 2009 Posted June 24, 2009 YES, I found where I got it from, here you go everyone! I found it cause I was watching this product cause it looked really promising and I liked it Here it is, it is free to the public: http://tp.skylighter.com/turbo-pyro/book1.asp?b=1&T=1 Quote from this website "http://www.turbopyro.com/" The Turbo Pyro eBook is FREE.
flying fish Posted June 25, 2009 Posted June 25, 2009 (edited) I just bought a small can of SIG NC laquer (sold as Nitrate clear aircraft dope) from ryder's hobby. Probably too expensive for general use but in a pinch (which I am in) a small can will get me by. The solvents used are ethyl acetate and MEK. I looked up evaporation rates, as I was hoping for something relatively fast drying. I started reading evaporation rates, and saw that these were marked with a low numbers (compared to methanol) on the data sheets I looked at. I of course assumed that this meant they had low evaporation rates. But it turns out the opposite was true! http://www.siegwerk.com/fileadmin/user_upl...on_rates_en.PDF . The lower the number, the faster the evaporation rate. I guess most of you people are going to say "Well, obviously!!!" But I'm learning...and amused at this kind of stuff. EDIT: Question for you guys: Any ideas for off-the-shelf tubes for cake shots? I'm looking for 1" tubing. Can be paper, or a non-shattering plastic. I was originally thinking perhaps PE tubing, but the stuff at my local hardware is very poor quality, not very round in cross-section, and bent axially as well (probably because it was cut from a circular spool). I'm hesitent to use PVC or ABS...on my property I wouldn't care, but this is for a beach shoot in which there may be some spectators in fairly close proximity. If there were a flowerpot, I'd rather not spray myself and spectators with bits of PVC. Edited June 25, 2009 by flying fish
TrueBluePyro Posted June 25, 2009 Posted June 25, 2009 ...If there were a flowerpot, I'd rather not spray myself and spectators with bits of PVC.... Yeah that can be a bit of a problem...
Mumbles Posted June 25, 2009 Posted June 25, 2009 The evaporation rate thing just proves why it was a good choice to go into physics, heh. As far as OTC tubing, you may want to look into small mailing tubes. I don't know about 1", but I've seen them pretty small. You could always roll your own.
Ventsi Posted June 25, 2009 Posted June 25, 2009 Ask your local post office / UPS office/ packaging center etc. for some extra tubes they have or are throwing away, or just ask them to dig around in their cardboard only dumpster, I got some HQ 1" tubes from out back the store they were throwing t away not too long ago. As for the mailing tubes, I think they only go down to 1.5" - 3' , thats how I get my 2" guns BTW.
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