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To really answer these questions you’ll have to build it…as Ripley would say, it’s the only way to be sure…
Does OR have a feature that lets you an altitude and speed for initial ignition? That is, "I'm starting out at xxx altitude and already going yyy speed"? If so, you could take the altitude and speed at burnout of the first stage of the full stack and enter them as the starting state of the second file, then repeat for the third and fourth. And then you'd have a chance of accurateish staging altitudes for each event and apogee.Sage advice... so it shall be written, so it shall be done.
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Why do you keep talking about CHAD? This design is not using CHAD. CHAD"Has any man ever Chad staged a 5 to 5 cluster?"
The initial drawing (first post) was cheap and dirty gap staging but has been removed. Each motor was in a seperate tube. Confirmed in post #9.Does OR have a feature that lets you an altitude and speed for initial ignition? That is, "I'm starting out at xxx altitude and already going yyy speed"? If so, you could take the altitude and speed at burnout of the first stage of the full stack and enter them as the starting state of the second file, then repeat for the third and fourth. And then you'd have a chance of accurateish staging altitudes for each event and apogee.
Why do you keep talking about CHAD? This design is not using CHAD. CHADhas leftnever entered the building. There is no CHAD. CHAD is dead.
as I recall, he died from hanging.. There is no CHAD. CHAD is dead.
Wasn't he pregnant too? He certainly was before his time; he'd be popular in certain circles in 2022 America.as I recall, he died from hanging.
I just got a visit from my inner RSO. Now he is questioning if there is enough velocity off the rail (not rod) to successfuly flash pan that cluster stage in a vertical position. He reminded me of all the high power staging requirements - tiltometers and such.
Yes, that. Fuse might really be the better idea. But then, I guess you've already decided to go that way; I'm late to the party.Part of my concern is the canted fins. The rocket will be spinning (per the sim) at 960 rpm's at 1st stage burnout. I'm thinking that won't be to conducive to black powder loose in a flash pan.
The sound of a record scratch leading to a sudden halt.Option 1: Flashpans! Rather than a cross-shaped flash pan, set up five little cups of 18mm tubing at the top of Stage 1. These are sealed on the bottom, open on the top, and aligned with the 5 motors above so that they fit over the base of the motor. A little dollop of BP in each will do the job. Connect them in a cross shape with the quick fuse so that when the center one flashes off, the outboards go very shortly thereafter. Connect the center one with the center -0 motor in the first stage as previously discussed. At 0.1s/ft burn rate...
Calculations like this, especially those with safety implications, must be conducted with worst case assumptions. It's 0.4 sec/ft.
I'm at work now (and shouldn't be on the forum, but I am) and I just had a bitch and moan session with another engineer about our company accepting simulations in lieu of qualification testing, and the trouble we have because of it while commissioning new (train) cars. The proof of the pudding is in the eating. Take a little taste of the pudding before serving it. It's the only way to be sure.To really answer these questions you’ll have to build it…as Ripley would say, it’s the only way to be sure…
Oh cripes! That just got me thinking harder about the flash pan. If the first stage tips by any noticeable amount, the loose powder would fall to the low side of the pan and really wouldn't get the job done.
I haven't heard of it either, and the fact that we're all brain storming ways to work around the probable problems would seem to be evidence (not proof) that it hasn't been done before. And perhaps evidence that it shouldn't be.My ignorance is again showing. I AM familiar with flash pans used to ignite first stage boosters off the pad. I haven’t heard of using flash pans IN FLIGHT to light sustainers or mid stage motors. Of course, there’s lots of memos I miss.
As Mom used to say, “ Just because you can do it doesn’t mean you should do it.”I haven't heard of it either, and the fact that we're all brain storming ways to work around the probable problems would seem to be evidence (not proof) that it hasn't been done before. And perhaps evidence that it shouldn't be.
I've never done flashpan inside a rocket... not sure I'd want to. If I were doing it, I'd use ultra fast burning paper fuse from one of the previous stage motors to the 5 next stage motors.
https://www.skylighter.com/collections/firework-fuse/products/quick-fuse-white-gn1207
It lights VERY easily (as easily as BP) and burns at 0.1sec per foot. 5 sections from the central booster motor to the 5 next stage motors is how I'd do it.
I see you plan on using BP motors. Get some very fast fuse https://www.skylighter.com/collections/firework-fuse/products/quick-fuse-white-gn1207 Check the nozzles of the motors and make sure you can see the BP grain and it's not covered with clay. Put in a few grains of BP and then a piece of fuse about 1" long. Then flash pan the fuses. An alternative is the MJG BP motor starters. These are small ematches that fit all the Estes motors and your altimeter should be able to fire them directly. They will not light composites without dipping and probably won't fit the nozzle of Q-jets.
Could that type of cluster fuse be braided together into a single cord fuse to run along the entire gap in between the sustainer nozzles and boosters, and then split again at the booster side into each ejection/ignition source, instead of a flash pan? That would be more like a flash cord fuse, instead of a pan, I guess. Is that feasible at all? Might hold together better in a spin-stablized rocket, maybe.
I used only a single booster motor so that all staging is based on that motor. The others were standard delay motors. I also wrapped the paper fuse (not quick match!!, that's regulated) with aluminum tape so that if the booster motor didn't fire for any reason, the delay motors didn't light the paper fuse
1st stage: 4x C6-5 & 1x C6-0. C6-5 had parachutes in their tubes and the C6-0 had the paper fuse taped into the ejection well.
2nd stage: 4x C6-5 & 1x C6-0. Same configuration as 1st stage
3rd stage: 1x C6-7 gap staged from central motor of second stage.
I used 1/16" plexiglass fins on 2nd and 3rd stage. From a distance, you could hardly see them. Very interested if this finless version will work. I have 3 of the 1/100 Estes kits and would be willing to build 1 of those as a 3 stage with finless 2nd and 3rd stages.
Could that type of cluster fuse be braided together into a single cord fuse to run along the entire gap in between the sustainer nozzles and boosters, and then split again at the booster side into each ejection/ignition source, instead of a flash pan? That would be more like a flash cord fuse, instead of a pan, I guess. Is that feasible at all? Might hold together better in a spin-stablized rocket, maybe.
Thanks for explaining this in such a detailed manner Aaron.Yes, 5 individual sections of fuse. At the booster end they were bundled together so that the booster motor ignited them all. Tied together with cotton kite string.
The fuse gives off almost no sparks/flames when burning inside the paper shell but it burns so fast you almost can't tell. To protect the fuse from one of the non-booster motors and to protect everything else from the fuse, I wrapped them in aluminum tape.
Starting from the C6-0, 5 sections of fuse with 1/4" of the insides exposed. All tied together into a bundle with thin cotton kite string and then a wrap of aluminum tape. The end of the bundle is not secured to the booster motor so that each stage can be prepared separately but the bundle fits down into the booster MMT freely. Up about 2 inches, the bundle split apart inti their individual fuses. Again wrapped in aluminim tape and leading up to the 5 motors in the next stage. Fuse ends were expised 1/4" and inserted into the nozzle and secured with the soft plastic nozzle plug and then taped over with aluminum tape.
When I did a test burn of the fuse in my backyard, I waved my mapp gas torch over the end and in what I can only explain as nearly magic, the 1ft section disappeared before I could prepare myself. If you've ever used green fuse on fireworks, this is absolutely nothing like that at all. It is much more like a pile of 4Fg BP that you toss a match into. Its there and then not. No sparks or flame, just fuse and then paper bits. Even assuming the 0.4 sec per foot, the 5inch sections burn in 0.17sec If its the fast version the 5inches burn in 0.04sec. 40msec!
The original term for these is "spider".I recently read of a very clever cluster lighter improvement on the flash pan. I think it was in a recent Sport Rocketry. Call it a flash can.
Thanks.The original term for these is "spider".
Not sure I agree with your math there. The D12 burns for 0.9s after the C11 burnout. at 0.1 to 0.4 s/foot, you'd need fuses 2 to 9 feet long. That seems really long. Any reason not to use a D12-0 in the center? If you end up with too much propellant for Class 1, you could switch down to C11's outboard (or 2 of the 4 outboards).Worked on the CAD drawings for the 1st stage....
Comparing thrust curves for a C11 and D12: If I use a C11 in the first stage to ignite the quick fuses for the 2nd stage... that means the 2nd stage motors should fire off just before the D12 1st stage motors burnout.
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Not sure I agree with your math there. The D12 burns for 0.9s after the C11 burnout. at 0.1 to 0.4 s/foot, you'd need fuses 2 to 9 feet long. That seems really long. Any reason not to use a D12-0 in the center? If you end up with too much propellant for Class 1, you could switch down to C11's outboard (or 2 of the 4 outboards).
Personally I'd accept that it needs to be a class 2 rocket with a waiver due to total propellant mass. Then use the fastest burning set in the first stage to get it going and stable. Then less fast in the following stages. The D12 has a good initial spike but are there better BP motors for the first stage? If B14s were available I'd suggest that but what about C5?
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