personal launch this past Sunday (bit long, maybe)

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graylensman

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I finally got to launch this Sunday, after too many weekends not able to! Fortunately, the Rocket Gods claimed no birds; but nothing came back without mishap. Doubly unfortunate - I forgot to bring a camera!

The sky was crystal blue, with hardly any breeze. Temperature was chilly, but not unbearable. Unfortunately, in my haste and excitement, I failed to powder my chutes: none opened.

The recovery crew was my 7 year old daughter and her friend. They were excited, but stood a very respectful 50 feet away at liftoff. But once ejection charges popped, they were dashing to the touchdown spots.

First up: a Midnight Express on an A8-3. Beautiful flight! One fin was crumpled on touchdown.

Second rocket: my Der Midnacht Express on its maiden flight. This also had a great flight on an A8-3. One fin was ripped loose on landing.

Third rocket: another 1st flight, this my Little John clone on a 1/2A3-4T. Perfect liftoff, though i had forgotten how short boost phase is on 13mm motors. The nose has a gouge in it, now; I expect that can be fixed easily.

Fourth rocket: my Estes SR-1 on a B6-4. At ejection, the shock cord snapped. But body and cone showed no other damage upon recovery.

Fifth rocket: a sport scale Alway Vostok. This is my veteran rocket, and my favorite to watch. It looks so cool heading skyward! But the chute didn't deploy properly, and it too suffered nose damage.

All in all, a pretty good hour of flying. I suppose I'd rather have rockets to fix as opposed to outright losing them.
 

vjp

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Fifth rocket: a sport scale Alway Vostok. This is my veteran rocket, and my favorite to watch. It looks so cool heading skyward! But the chute didn't deploy properly, and it too suffered nose damage.


Gray - thanks for the launch report! Can you elaborate on the Alway Vostok? I just finished mine, kinda sorta half Peter Alway's design and half my own. All-up weight is just under 10 oz., without motor, and I'm trying to decide between flying her on a D12-3 or a D12-5.
 

graylensman

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It's an 18mm motor mount, BT-50 based. all the shrouds rolled from standard bond paper. The nose cone I actually constructed out of paper, as well - BMS couldn't turn a nose to those specs, and I haven't been comfortable with my own abilities to turn one on my own. For nose weight, I used lead fishing sinkers. They work fine. I don't know the weight, but it balances just at the tips of the strap-on boosters, a smidge ahead of where Alway recommends. (That's with a C6-5 in place; a D motor will obviously change things.)

Three construction notes:

1.The strap-ons bow inward along the glue seam, so the only true points of contact are at the tip and one spot where the long cone transitions into a straight cylinder. For painting, just mask off those spots on strap-on and core.

2. Construct the strap-ons out of slightly heavier paper. I've got a new set rolled from 32lb. bond. I expect them to stand up a little better.

3. If you're using balsa for the bottoms of the strap-ons, run the grain perpendicular to the core body tube. This may seem obvious, but it wasn't to me until I had one crack on touchdown.

I've flown it on an A8-3 and a B6-4. It's too heavy for the A motor, and a 4 second delay is a little long. I haven't tried a C motor yet, for fear of never getting it back.

Let us know how yours goes!
 

vjp

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Gray - thanks for the tips. I think there are two different Peter Alway Vostok plans out there, the one I built was based on BT-55 and BT-60 tubes, hence it's a little larger than yours. The data about the CG is very helpful - I am aiming NOT to crash mine on its first flight! And without fins in the traditional sense, it's a tough call to make.

I have FINALLY completed mine (although I may make one or two more cosmetic tweaks, it's ready to fly) and I'll be posting shots shortly.

Thanks again!
 

graylensman

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Originally posted by vjp
without fins in the traditional sense, it's a tough call to make.
that's the one single aspect of this rocket that surprised me. Every flight has been straight and true: little or no roll, no weathercocking to speak of. I guess the strap-ons provide the necessary lift force, because I can't imagine those tiny triangle-shaped fins doing all the work.

Looking forward to your pics!
 

vjp

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Originally posted by graylensman
that's the one single aspect of this rocket that surprised me. Every flight has been straight and true: little or no roll, no weathercocking to speak of. I guess the strap-ons provide the necessary lift force, because I can't imagine those tiny triangle-shaped fins doing all the work.

Looking forward to your pics!
That's reassuring - THANKS! The stability issue has worried me more than any other aspect of this project. I plan on flying it a lot, slowly changing the CG, to gather lots of data points on stability.

I suspect that the wind pressure between the boosters, with the air being squeezed out between them as they widen towards the base, may induce a strong corrective force. That, and the strong base drag, may be serving as a kind of "pseudo-fin" equivalent. I'd love to see how this vehicle looks in a wind tunnel.

I posted some photos of mine in the scratch-building section.

Thanks again!
 

eugenefl

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Thanks for the launch report. It's nice to head out on your own and fly a few rockets! I tell ya, I am equally pleased to see rocketeers having fun with their friends, family, or even solo! Thanks for sharing...

One thing is for sure, it's better to bring home a casualty than to lose one outright. Jason T. crashed his 24mm Deuce this weekend but he *did* get to bring it home. What's better is that this is a Jim Flis autographed Deuce. At least he can preserve it and relish the moments when it did fly.
 
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