#1
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DECAP's
DECAP's (delay ejection charge auxillary packages) are not on the survey, but I have done some work characterizing them. The projected prices show a difference in booster engines and delay engines. This reflects the fact that a booster takes 2 seconds less to make than a delayed engine and the cost of black powder is about the same as the cost of the delay in an 18mm A engine, so there is a real cost difference.
Briefly, a DECAP is about .51" diameter by 1.2" long and glues inside a booster engine to add the delay and ejection charge. They would be available in all times from 2 seconds to 9 seconds. They would also be available as .5 g ejection charge (standard 18mm load) and 1.2g ejection charge (standard 24mm load). So if you wanted a B5-5, you would glue a DECAP-5 inside a B5-0 engine. If you wanted a C5-4 in a long, large diameter tube, you would glue a DECAP-4X inside a C5-0. Retail price for a singe DECAP is going to be in the $1.00 range, but the difference in an 18mm booster and delay engine is about $.75. So a B5-4 would cost about $3.25 if prepackaged, but $3.50 if it was made with a booster and DECAP. Questions are: 1. Would it be worth the extra $.25 to have the ability to select delays? 2. Would the average (over 18) user be able to "figure it out"?
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Carl McLawhorn NAR#4717 L2 semroc.com |
#2
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Carl,
That is very interesting.... I know I have found myself in situations where I wished I had a delay between existing available delays amongst Estes/Quest motors - your example of a 5 second delay on a B impulse motor is certainly one of those. So - I vote "yes" on question number one. On number two....not so clear. If all goes the way you wish it to, how widely would your motors be available? The reason I ask is that I expect a bit of a difference in the willingness to be careful and pay attention (and the ability to follow directions) between those who would seek an alternative to mass-marketed motors either directly from you or from specialist dealers compared with those who might just encounter rocketry products in a mass-market type store. You're suggesting the need for something not unlike the understanding necessary to assemble reloadable motors successfully. I wonder how much handholding Aerotech or Apogee or Cesaroni or such have to do?
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Bernard Cawley NAR 89040 L1 - Life Member SAM 0061 AMA 42160 KG7AIE |
#3
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My thoughts:
1. Yes, of course. 2. Installing a DECAP sounds like a much simpler process than, say, assembling a reloadable motor. AeroTech and CTI seem to manage just fine by including detailed instruction sheets with their motors. I don't know how many reloadable motors and reloads are sold to naive customers who have no idea what they require and I suspect that most people who buy them have some notion of what they are all about. This does not mean that every customer uses them properly, but the rocketry community is swift to condemn anyone who squawks about a motor failure when it is evident that the person didn't follow the directions for its use. Black powder motors have a lower "education" threshold for potential consumers, but even novices have to read some instructions before they even know how to ignite them properly. I think that the imagined scenario of a totally naive customer buying black powder motors without having a clue about how to use them isn't actually that likely; most people would not be inclined to buy something that they have no idea how to use. So the vast majority of your potential customers would either know already what they were getting or would at least realize that they needed to read some instructions on what to do with the darned things. So, yes, I think that the average user would be able to follow the instructions in order to use the product properly, especially if the packaging and the motor label clearly indicates that a delay and ejection charge module must be added to the motor to make it capable of deploying a parachute or streamer.
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Mark S. Kulka NAR #86134 L1,_ASTRE #471_Adirondack Mountains, NY
Opinions Unfettered by Logic • Advice Unsullied by Erudition • Rocketry Without Pity
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#4
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I'd doubt the wider market appeal of them, from from a competition perspective I can say this would be VERY attractive. Once certified, you'd probably get a few of us that would just load up on a hundred or so because whenever we find something this good, we buy a lifetime supply before it disappears.
I do think the delay flexibility would be worth it as an option, not as a forced standard. I think most over 18 would be able to figure it out. I just think most flyers really aren't going to pay much attention to the difference between a 4 and a 5 second delay. If their chute comes out and their rocket comes back, they're happy. Slightly before/after apogee is for the purists. |
#5
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Yes and Yes, but as Bernard mentioned, you'd have to be prepared for a lot of virtual hand-holding for number 2. Enlisting SAM members to help out on that could be a major plus.
It sounds a lot easier to do than a typical AT reload, somewhat easier than a Loki, but not as easy as a CTI. To me though, if you can glue fins on the right end of the body tube you should be able to do this. Buzz
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Quando Omni Flunkus Moritati |
#6
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Quote:
1) Definitely! 2) I would certainly hope so - if they can put a rocket together, they should be able to handle a DECAP.
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Up next: Under construction: Under repair: In finishing: Centuri Sabre clone In primer: In paint: Ready for decals: Bill Cooke NAR #31312 TRA #19705 SAM #0001 Huntsville, AL My rocket blog My rocket fleet |
#7
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1) Yes
2) If they can't figure it out they shouldn't be flying rockets
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Did the chicken really cross the road, or did the road move beneath the chicken? Albert Einstein You Can't break the laws of physics but they can break you. Christine McKinley Dale Greene Mentor, Penn Manor Rocket Club VISIT SPAAR 2010 Calder Cup The Old West 2009 Calder Cup " Speaking the Truth in times of universal deceit is a revolutionary act. " George Orwell |
#8
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Having worked Standards and Testing way back when, I think you would have to get their input about what they would certify both from a safety and a contest certification point of view. I have WAY too many 18mm composite reloads as once a pak is impounded and then opened, it cannot be used for competition again (must be an unopened pak). This is so the modeler does not "modify" components. This could be carried oper to a multipak of delays.
Seeing as some of the S&T members will be at NARAM for the Board of Trustee meeting, you might want to take them into your confidence and see if they have issues or suggestions. We didn't call it Standards and Torture fur nuthin'! Chas BoT 9 years, S&T 3 years, first MESS chair, NARTREK 3 years or so, Contest Board very briefly before overseas assignment... and the beatings go on.
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Charles Russell, MSgt,USAF (ret.) NAR 9790, Lvl 1 SAM "Balls Three" Last edited by Chas Russell : 07-20-2011 at 02:33 PM. Reason: Typo |
#9
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The DECAP idea sounds great !
Every delay for every engine. As a side note, one could do all sorts of "unique" things with say a B5-9 in a large rocket....buuuwwhhhaaaahaha ! NAR needs to relax their draconian competition rules regarding reloads, PERIOD. There is no reason AT ALL why they could not re-seal the 3 pak with a special NAR only tamper-proof seal.
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When in doubt, WHACK the GAS and DITCH the brake !!! Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't ! Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY. ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC ! |
#10
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Quote:
Draconian rules? Sheesh, get over yourself. The reload rule is pretty stupid, but so is complaining about it when all it takes is writing up a rules change proposal and shooting it off to the appropriate volunteer (Jim Filler at the moment). Once a year everyone gets to vote on the proposals, and whatever passes goes into effect. The NAR itself doesn't write any rules or make any decrees. It's about the most grass roots, democratic, power-to-the-people part of the NAR and I'd think that's a bandwagon right up your alley for jumping on. Out of curiosity, how many contests have you flown where you were either incovenienced by this Draconian rule, or did not fly specifically because of this Draconian rule? |
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