hst45 Posted March 27, 2008 Posted March 27, 2008 We've all had it happen; the best designed devices don't work exactly as we planned. Usually it's something mundane like stars that blew blind, a time fuse fails, or a rocket CATOS. BUT, every once in a while, something goes wrong that gets captured on video that is kind of amusing. This thread if for sharing those moments. This first video is my attempt to construct a 2-stage 4 oz. coreburner BP rocket. I fabricated 2 motors, added stabilizer sticks, placed a BP pass-fire charge between the stages, aligned them with a cardboard collar, and added a 5 gm. 70/30 header to let me know when the second stage hit its apogee. Well, let's just say that the flight dynamics aren't what I hoped. This video is from another rocket on another night. I guess that the fuses' horoscope said that this night was a bad time to travel.
pudidotdk Posted March 27, 2008 Posted March 27, 2008 Okay here goes:I made a 22 mm stinger, the stinger launch spindle was too tight for the nozzle, and it didn't take off.Funny thing is that I just threw roughly 3 grams of 7/3/1 Ti flash at the top, thinking I would get a nice shower of sparks in the air... well I will now think twice before putting something on rockets before testing if they even get in the air!http://pyrobin.com/files/stingerfail.wmv The good thing is that you learn of your mistakes, so there is at least something you get out of failures
TheSidewinder Posted March 28, 2008 Posted March 28, 2008 Hmm... just worked for me. Nice bomb-on-a-stick. I noticed everyone started running. Can't imagine why. M
qwezxc12 Posted March 28, 2008 Posted March 28, 2008 hst, Loved that Tree-killer! I had a few videos of shells launched with a bum batch of BP lift, but can't seem to find them...there's a nice one of a 3in green Ti going up and coming down about 60ft. from the camera, slightly inside the burst radius I did find this one from last winter...What do you get when your nozzle is too small, you've spiked your propellant with too much flake Al, and you've put a large header on an experimental rocket? Hillarity... 1lb. endburner CATO *edited*I found another concussive misshap: A 4in can shell with 15g salutes and a 100g bottom-shot. The fuse timing was a mite long on the bottom-shot...this why I shoot shells in a rural environment...4in Salute Can ground attack
oskarchem Posted March 28, 2008 Posted March 28, 2008 Aha, I think this will be a interesting thread, so here is my BP core burner CATO, where I drilled the core wayyy to long and it lit the BM on the other side. But at least I know the effekt was good http://fr.youtube.com/watch?v=67dIkV_wYA0 And my core burner that went missile, into a tree ttp://fr.youtube.com/watch?v=4bRlTb86_mE
Frozentech Posted March 28, 2008 Posted March 28, 2008 My classic rocket cato from a couple years ago. (ALWAYS use a bulkhead with a passfire when you top a rocket with 28 grams of flash) Turn up the volume Also, don't curse yourself by launching on a full moon, and saying "please don't cato" ! I've had louder failures, but not by much.
RubenE Posted March 28, 2008 Posted March 28, 2008 Hehe, I've had a few mistakes myself:I had previously that day been using some granulated green mix as a filler in some stuff, so I managed to use it as lift for a 4in ball shell too: And, a long time ago, when I was using visco as time fuse I had a shell that didn't burst because I didn't prime the fuse good enough. I got it on video, but I doubt anyone wants to see the lift go off and a momet later you hear a splash in the water. That was really a shame. But now, years later, I got the hang on cross matching, and I'm the lucky owner of some real time fuse!
marks265 Posted March 30, 2008 Posted March 30, 2008 My oops here was cheap wire to string the waterfall. It was over 20 feet long and every 5th one or so I tried a violet comp. which spoiled the effect as well! It was still well worth the effort. The wire broke once will hanging and then I thought I was OK http://www.youtube.com/watch?v=CyNDgSUA3eE
al93535 Posted March 30, 2008 Posted March 30, 2008 ahhh a nice thread, I have several mishaps to post here. first I will show off a few 1 lb rocket cato's http://www.apcforum.net/files/another1lbcato1.wmv http://www.apcforum.net/files/1lbcato2.wmv http://www.apcforum.net/files/1lbcaton1.wmv http://www.apcforum.net/files/1lbcato4.wmv http://www.apcforum.net/files/doublebreakCATO2.wmv http://img.photobucket.com/albums/v242/al93535/cato.jpg Damn stars were too big and came back to the ground http://www.apcforum.net/files/sadrocket1.wmv Here is a 4" can shell that didn't really malfunction, but the ABS mortar couldn't handle the pressure. It was completely shattered when I went back to look for it. the shell didn't make it much higher then the HV power lines that you can see when the flash illuminates them from the salutes. http://www.apcforum.net/files/4inchcan4.wmv http://img.photobucket.com/albums/v242/al93535/bigcan.jpg http://img.photobucket.com/albums/v242/al9...brokemortar.jpg My 6" can shell that flowerpotted: http://www.apcforum.net/files/6inchflowerpotfarfalle1.wmv http://img.photobucket.com/albums/v242/al9.../farImage12.jpg http://img.photobucket.com/albums/v242/al9.../farImage13.jpg
psyco_1322 Posted March 31, 2008 Posted March 31, 2008 I have a few with me now, but Ill get some of the better ones posted later First is a blue strobe rocket I made on some core burner 4oz tooling, I just replaced the bp with the strobe comp, it was nozzled! Second is from the PGI convention that me and asilentbob made. It had 24oz of trimethyl borate on a 3lb nozzle less rocket. It started coming back down when the bursting charge went off. We even drilled out some of the delay so it wouldnt burn so long. It surely would have came very close if not to the ground. I figured that the rocket being upside down caused the flash to blow the rocket off the bottle instead of the other way around if it were rightside up. Had a little 8oz acetone header on a 1lb work perfect though. Same no one got a video. http://www.apcforum.net/files/S4020735.AVI http://www.apcforum.net/files/PGI_07_a1.jpghttp://www.apcforum.net/files/3lb-nozzleless-greenghost1.wmv
hst45 Posted March 31, 2008 Author Posted March 31, 2008 This was an attempt to make a 2" canister shell. My spiking was, in a word, disastrous. The sides of the canister held and the ends blow out, giving the effect of a bow-tie. The stars are PGF's charcoal streamers. Stingers are wonderfully fun little devices. The whizz, roar, fly, and leave a nice sparky trail. They apparently don't lift a header all that well, at least the ones I make don't.......I know that NOW..... This one is actually labeled wrong; it's a 1 lb. end-burner. I put on a crackling flying fish header, lit the fuse and started rolling tape. Notice that at around the 9 second mark the screen goes dark. Mental-note-to-self, don't fire a rocket with a 600 feet apogee into a 300 foot ceiling! The good news is that I can honestly say that I launched a rocket that went so far it disappeared into the clouds. This last embarrassment of the day is a 1 lb. core-burner that cato'ed, but lit the separation charge at the header, lit the time-fuse on the shell, launched the shell maybe 50 feet, and gives us a nice- sky-filling break with granite stars...o.k., maybe more of a "face-filling" break....as the stars are landing all around as I film. (no redneck pyros were harmed during the filming of these embarrassments.) Great fun, even when things go wrong.
justanotherpyro Posted April 2, 2008 Posted April 2, 2008 I used a new launch tube that has a slightly larger ID for a 2 inch easter egg shell and I didn't use enough lift. Dad thought it was cool though and nothing caught on fire so not a total loss. http://www.apcforum.net/files/2inchTTlowbreak.wmv *EDIT* I couldn't let that crappy shell slide, so I remade it and voila 20 minutes later http://www.apcforum.net/files/2inchTTremake.wmv Dad liked it again, mom OTH even though she was inside did not As you can tell I was a little over zealous on the lift this time, and the pasting job was crap too but it works.
crazyboy25 Posted April 2, 2008 Posted April 2, 2008 Well I have a few: (not a surprise we used a stick to shove it into the mortar) (not mine but it came after me and the kid standing next to me.)
hst45 Posted April 14, 2008 Author Posted April 14, 2008 I'm not experienced with can shells, as this video shows. I tried a 2" D-1 shell. I made a cardbord tube, spiked it, and ended up with a shell that was a bit larger than I'd planned. I dropped it into the mortar....well,... it wouldn't *drop* into the mortar so I gently eased it into the mortar.... O.K.,... it was a tight fit so I *pressed* it into the mortar,....well... maybe it was more than a tad tight, so your might say that I rammed the hell out of it to make it fit the mortar.....I'm sure that nothing will happen wrong with that.....(down in front...)
FrankRizzo Posted April 15, 2008 Posted April 15, 2008 I'm not experienced with can shells, as this video shows. I tried a 2" D-1 shell. I made a cardbord tube, spiked it, and ended up with a shell that was a bit larger than I'd planned. I dropped it into the mortar....well,... it wouldn't *drop* into the mortar so I gently eased it into the mortar.... O.K.,... it was a tight fit so I *pressed* it into the mortar,....well... maybe it was more than a tad tight, so your might say that I rammed the hell out of it to make it fit the mortar.....I'm sure that nothing will happen wrong with that.....(down in front...) Your passfire didn't communicate fire to the lift charge.
justanotherpyro Posted April 16, 2008 Posted April 16, 2008 I'm not experienced with can shells, as this video shows. I tried a 2" D-1 shell. I made a cardbord tube, spiked it, and ended up with a shell that was a bit larger than I'd planned. I dropped it into the mortar....well,... it wouldn't *drop* into the mortar so I gently eased it into the mortar.... O.K.,... it was a tight fit so I *pressed* it into the mortar,....well... maybe it was more than a tad tight, so your might say that I rammed the hell out of it to make it fit the mortar.....I'm sure that nothing will happen wrong with that.....(down in front...) Your passfire didn't communicate fire to the lift charge. If that is the case then the shell was top fused with the leader passing over the time fuse or spollete. It's an uncommon technique for smaller shells vs bottom fusing and getting fuse ignition with the lift charge. That what puzzles me is that it doesn't look like the lift charge even goes nor does it sound like the shell was loaded upside down. Also, hst45 said that he had to ram it down which would potentially damage the time fuse if it was on the top.Would you elaborate a bit more on the shell construction hst45?
hst45 Posted April 16, 2008 Author Posted April 16, 2008 Would you elaborate a bit more on the shell construction hst45?Sure, glad to share the knowledge, or in my case, the ignorance. I top fused the shell with visco wrapped in electrical tape, and split the end of the take-fire side and dabbed on a bit of homemade NC lacquer and dipped this in milled BP meal. This timefuse technique works flawlessly for me in ball shells and I don't imagine it works any less well in can shells. I ran a quickmatch fuse to the lift charge. At about the 4 second mark in the video you'll see the lift charge light. This must have lit the timefuse, which blows the break charge at about the 8 second mark, resulting in a cardboard mortar which turned to confetti. The problem was in my underestimation of the increase in diamiater that the spiking would add to the shell. When I went to load the shell into the mortar it was obvious that I had made the shell a bit oversized, but I hoped that it would launch....I thought that it would launch.....I assumed that it would launch......but, well, I guess I guessed wrong I need to do a lot more work on can shell construction.....
justanotherpyro Posted April 16, 2008 Posted April 16, 2008 How much lift did you use for the shell? I have had very tight fits before and the only difference if the shell doesn't flower pot is that the launch sounds like a cannon instead of just a nice thump. The lift gases have to go somewhere so if the shell was really tight in the mortar, didn't flower pot and didn't even get popped out of the gun, maybe the lift charge was way to weak?
FrankRizzo Posted April 16, 2008 Posted April 16, 2008 Would you elaborate a bit more on the shell construction hst45?Sure, glad to share the knowledge, or in my case, the ignorance. I top fused the shell with visco wrapped in electrical tape, and split the end of the take-fire side and dabbed on a bit of homemade NC lacquer and dipped this in milled BP meal. This timefuse technique works flawlessly for me in ball shells and I don't imagine it works any less well in can shells. I ran a quickmatch fuse to the lift charge. At about the 4 second mark in the video you'll see the lift charge light. This must have lit the timefuse, which blows the break charge at about the 8 second mark, resulting in a cardboard mortar which turned to confetti. The problem was in my underestimation of the increase in diamiater that the spiking would add to the shell. When I went to load the shell into the mortar it was obvious that I had made the shell a bit oversized, but I hoped that it would launch....I thought that it would launch.....I assumed that it would launch......but, well, I guess I guessed wrong I need to do a lot more work on can shell construction..... How did you ignite the shell? Did you have a quickmatch leader, visco, etc. going down the bore to the shell, or did you side-fuse the mortar into the lift? My comment about the passfire not working was based on an assumption that you used some sort of fuse down the mortar, and the spark activity is exclusively from that. justanotherpyro: Cannister shells (even small ones) are always top-fused if made with traditional techniques.
hst45 Posted April 16, 2008 Author Posted April 16, 2008 Frank, I used a quickmatch leader from the top of the mortar down to a lift-cup of BP. My problem, in retrospect, was that I spiked it with string that was so thick that it added to the overall diamiater of the shell to the point where it was too tight. I knew it when I loaded the shell, too. Take a look at the video and you'll see that I didn't move the camera up when the lift charge fired; I knew that I was rolling tape on a potential, or actually probable, CATO, but by the time I had the shell loaded I thought, WTF, light the fuse and what's the worst that can happen. (see above link ) EDIT: I posted the above last night, and since then I had a chance to think about why you asked. If I hear you right, you saying that the first flash might be just the quickmatch, and that in forcing the shell into the tube I crimped the quickmatch so it didn't reach the lift, but did make it to the timefuse on the top of the shell. That would actually make good sense, as it explains why the LIFT didn't blow the tube before the break charge. Sorry it took me so long to figure out what you were telling me. Thanks.
TheSidewinder Posted April 17, 2008 Posted April 17, 2008 I can confirm part of that. A too-tight shell, OR a too-tight cinch on the string used to wrap the final layer (the QM passfire to the lift being under it), can cause the lift to fail, but the timefuse lights. Happened to someone at WPAG my first year, but I don't remember who it was. They were new to shell-building, but not a true beginner, is all I can remember.
ST1DinOH Posted April 17, 2008 Posted April 17, 2008 I can confirm part of that. A too-tight shell, OR a too-tight cinch on the string used to wrap the final layer (the QM passfire to the lift being under it), can cause the lift to fail, but the timefuse lights. Happened to someone at WPAG my first year, but I don't remember who it was. They were new to shell-building, but not a true beginner, is all I can remember. wow... i always figured that the shell would leave no matter what. thoes gasses have to go somewhere, and unless the shell is wedged in so tight that it provides more resistance than the plug and the side walls of the gun then the shell should leave the tube. whatever force it takes to get that shell down there, or back out again has got be far less than the force provided by the expanding lift gasses.
TheSidewinder Posted April 17, 2008 Posted April 17, 2008 Well, for the shell to leave, the lift has to be ignited. Failure of the passfire means the lift never ignites. (Well, not until the whole shell goes, anyway, and at that point it's a bit too late. )
Mumbles Posted April 17, 2008 Posted April 17, 2008 hst worded it in a way initially that made it sound like it was not top fused. "Frank, I used a quickmatch leader from the top of the mortar down to a lift-cup of BP." In his edit he clarifies it as being top fusing. Trust me, with even 10g of BP, that gas is going somewhere if it gets lit. The shell is either going up(in one piece or not), or the mortar is going outward.
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