Judging from the MSDS on the Aerotech web site, the First Fire igniters use the same conductive pyrogen as Copperheads. So it would appear that the First Fire is also a conductive pyrogen type igniter. This will result in a lot of unit to unit variance which is always bad news for clusters.
I was going to sacrifice a First Fire to check on its construction, but they seem to have all scurried for cover.
No flames intended here, but you just answered your own question.
They are simply not reliable and/or efficient enough for clustering.
I have used M-Teks exclusively for the past year or so and have not had any issues with their current match not lightning magnalite. I don't know about other pyrogens, but I have had a 100% success rate. YMMV.
I tried to use Quickbursts matches with a copper thermite mix and it failed. I did only try once though, so who knows. I'll try to talk my friend into donating more of his Quickburst matches for further testing. Of course, my mix could be wrong, though it did work flawlessly to ignite the three motors I use it on, and M-Teks have worked flawlessly as well. Again, YMMV.
Mark A Palmer wrote:
It's the part of Phoenix that is located on the south side of South Mountain. It's really Phoenix, and it's south of what is normally called "South Phoenix". (think Ray or Chandler Blvd and I-10, but on the west side of I-10.
Where in the valley are you located?
Both SSS and AHPRA go by the "missfire alley" launch methods (last I knew). Normally, everyone has their own pads and launch controllers, but most folks will allow you to borrow theirs.
You'll be "pushing your own button" for the launch. Once you get used to it, you won't want to go back!
AZ Woody, I know where that is, but after 2 months here I still get lost. Last week a friend from church and I hiked up North Mountain. Are there trails on South Mountain? We're at W. 37th Ave.and Orangewood, almost to Glendale. I haven't pushed my own launch button since the time I launched my EZI-65 on a H112J. It'll seem strange at first. Do you still launch with SSS? Larry Lobdell Jr.
Hi Mark, Good to hear from you. I miss you rocket people back in MI but I won't miss trying to prep rockets in the freezing cold at Michiana winter launches! If you still launch HPR at MIS, I'll try to plan my vacation so I can come launch too. Now that our kids are out of the house I can fill the car with rocket stuff (if my wife's not looking when I load it up :)
Hey, remember when you were LCO for the first launch of my 2-stage? I built a new first stage with a 54mm main mount and 2 strap-on 38mm mounts. I launched that for the first time at LDRS in Geneseo. Man was it cool. The next day I launched it again with three I284s in the booster. All 3 lit and it really took off, but then it self-destructed at max Q. I knew I shouldn't have accidentally restricted that altimeter vent hole :(. The booster was OK but the sustainer was toast so I rebuilt it and now it's ready to fly again.
Since my LEUP has expired and the ATFE is making it hard to get e-matches (what's left of my supply I want to use for air-starts), I am looking for an alternative. However I gather from this thread that clustering FirstFires is no more popular than using crapperheads. So I guess it's back to the drawing board... Larry Lobdell Jr.
Can you give some details on how this is done? THings like rules, who qualifies to push etc.
Thanks Phil
Most folks provide their own pads and controllers. You get to the range, and set up at the distance you'll be flying, at or near a pad marker - a sign that was placed at each pad spot, that can be seen from the flight line, with a "pad number on it"
When you're ready to fly, you just take the bird to the RSO to check and initial the card, then take it to the pad (no waiting for a pad).
When ready, you give the LCO your flight card, and he/she puts it at the end of the queue. The LCO calls names and pad #'s and that flier then pushes their own button. (the LCO does the countdown)
In the event of a "miss fire", the flier is given back their card, then fixes the issue, and then returns the card to the LCO (bottom of the queue again)
An advantage at the SSS site, is that it's big. For a pad at the "M" distance, you can have a few pads that not only are "safe distance" from the flight line, but also "safe distance" from each other, so one pad can be in prep when another is ready to go. (even at the H and below levels, there is often "safe distance" between pads.) Laying out the pad # markers in the only prep required by the club on the range itself, and the only clean up afterwards (well, except trash.....).
Last I looked, the sss website (sssrocketry.org) has a more detailed description, including a position called R-SOB (or really RSO-B). A second, and maybe third RSO who's only job was to keep an eye on the range.
As someone that went from L0 thru l3 using this system, it's not really expensive for fliers, and may in fact be safer. I built a relay controller based on plans on ROL years back, and used phone cords, so I can go from 50' to hundreds of feet. It might have cost me $30 (not including the battery, which I've had to replace once in 5 years).
Bought a quad pod years ago (Good old rocket vision!) and it was in the $100-$150 range IIRC. But before I got L2, used a "plumbers pipe" (PVC pipe and connectors) pad, that maybe cost $15.
On the safety side, when I'd be prepping a flight, I'd know exactly what was needed. What size rods/rail was available, if the cont check on the controller might trip the igniter, and if the controller can actually trip the igniter when needed, etc.
I've been to launches that don't use "missfire", and had to wait for a rail, or a 1/4" rod, and then found the clips so gunked up, or the rod so gunked up that's I'd need to clean them. That doesn't happen if it's your own equipment. You can clean them at home, and not in the middle of a dry lake bed! Also, as a flier, you are much more familiar with the pad if it's the same one you use again and again.
Like I said, even for a L3 capable setup, the cost was maybe $200, and for one that could be used for L1, maybe $40. Of course, much more "could" be spent, but I'm thinking what can "done on the cheap".
In both case not much more than the cost of a single motor at worst.
If you think it's a rush when the LCO "pushes the button" for your L3 cert, you should try it when you push the button yourself! (and if there are problems, you can't blame the pad, the controller, or the LCO - the ball in completely in your court!)
For anyone curious, the 7 motor cluster worked great! All 7 motors lit on the pad with the G40 comming up to pressure about 50 feet above ground. 4.5 pound rocket (LOC Ultimate) went about 3,500 feet.
-Aaron
Anyone remember Martin Philyaw's rocket that clustered 38 Aerotech G motors with copperheads?
Now Darrell, just because you CAN doesn't mean you SHOULD.
;-)
Larry,
JMRC is still flying at MIS in the summer. You know you are always welcome.
Yes I remeber that flight quite well. It actually kind of gave me an itch to do staging. You always made it look so easy. Experience has told me since that the amount of pre-flight prep is incredible (2 rockets preps for the price of one flight)!
Mark
Thanks Mark - I'll try to get to one of the launches there. Really, staging is easy isn't it? At least the theory behind it is. You just have to remember a few more things. Ask Roger Coates about the time I almost forgot to turn on my electronics. Now that would have been a great flight - NOT! I agree completely with you about the added amount of preflight prep. But for me it just feels more exciting to watch one good staged flight where everything works than to watch two single-stage flights. The more room for error and malfunction there is, the more sense of accomplishment I have when it all works right. I bet you felt the same about some of your big cluster flights. And I bet those took some serious prep time too. I have a new first stage for that rocket - it has 2 38mm parallel boosters (a la SRB's). I was thinking of ground starting 2 I435T's and airstarting a J540R with a sense of first motion timer. Most of the stuff I read says it would be safer to ground start the center J540 and airstart the I435's because that lessens the possibility of unbalanced thrust if one of the outboards doesn't ignite. You've done some interesting clusters so what do you think? Larry
Thanks Mark - I'll try to get to one of the launches there. Really, staging is easy isn't it? At least the theory behind it is. You just have to remember a few more things. Ask Roger Coates about the time I almost forgot to turn on my electronics. Now that would have been a great flight - NOT! I agree completely with you about the added amount of preflight prep. But for me it just feels more exciting to watch one good staged flight where everything works than to watch two single-stage flights. The more room for error and malfunction there is, the more sense of accomplishment I have when it all works right. I bet you felt the same about some of your big cluster flights. And I bet those took some serious prep time too. I have a new first stage for that rocket - it has 2 38mm parallel boosters (a la SRB's). I was thinking of ground starting 2 I435T's and airstarting a J540R with a sense of first motion timer. Most of the stuff I read says it would be safer to ground start the center J540 and airstart the I435's because that lessens the possibility of unbalanced thrust if one of the outboards doesn't ignite. You've done some interesting clusters so what do you think? Larry
Thanks Mark - I'll try to get to one of the launches there. Really, staging is easy isn't it? At least the theory behind it is. You just have to remember a few more things. Ask Roger Coates about the time I almost forgot to turn on my electronics. Now that would have been a great flight - NOT! I agree completely with you about the added amount of preflight prep. But for me it just feels more exciting to watch one good staged flight where everything works than to watch two single-stage flights. The more room for error and malfunction there is, the more sense of accomplishment I have when it all works right. I bet you felt the same about some of your big cluster flights. And I bet those took some serious prep time too. I have a new first stage for that rocket - it has 2 38mm parallel boosters (a la SRB's). I was thinking of ground starting 2 I435T's and airstarting a J540R with a sense of first motion timer. Most of the stuff I read says it would be safer to ground start the center J540 and airstart the I435's because that lessens the possibility of unbalanced thrust if one of the outboards doesn't ignite. You've done some interesting clusters so what do you think? Larry
Oh no - duplicate posts again! Sorry. Larry Lobdell Jr.
"Darrell D. Mobley" wrote in news:A8- dnamCGIR2w7zYnZ2dnUVZ snipped-for-privacy@comcast.com:
Did they ALL ignite?
Strange, that's what she said.
EVERY one. But he had an very unconventional method.
I have to admit that the three staging projects I have done (or been involved in) have been somewhat nonstandard adding to the complexity factor. The first staging project was a monotube hybrid to monotube hybrid in a 2 inch airframe. It was narrow, space constrained and had a lot of plumbing (LOL). The second was in April at Three Oaks and was clustered in both of the stages (7 J570's to 3 J570's), and the booster and sustainer were both set up for dual depolyment. The last was a team project with Scott Miller and Jim Russell at Black Rock 2 weeks ago and was an M to M flight in a 3 inch airframe that was also space constrained (aomng other challenges). I have however been kicking around a more standard 4 inch 2 stage model using
54mm mounts.Lighting 2 outboards first is a bit of a risk...but that is what makes it challenging and fun. Using Blue Thunder does tend to lessen the risk substantially as they light quickly and reliably. Also consider using CTI Pro 38's in the outboards for teh same reason.
When using AT reloads in a cluster, I usually least doctor the top fuel grain or two (score them up a bit and apply a little bit of pyrogen). I believe that with Blue Thunder, the pyrogen is unnecessary. Redline, White Lightening and Black Jack require a little more insurance!
Mark
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