I read through the L3 documentation post from the first guy who responded and had a link to all of this documents drawings for his L3, I think he did a marvelous job on it.
What did you do rocket wise today?
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Nice lack of spin on that flight. Must be built straight!
Watched the deployment in the first video a bunch of times. Interesting how it still has quite a bit of airspeed at deployment. The nose cone drives the chute forward and fully opens it, then, the sustainer comes past and yanks the chute along before getting turned around. Even beautiful flights like that can have some zipper potential.
I picked up a Long Ranger at Hobby Lobby. Figured it would be an almost-builds-itself mule to try out some stuff that isn't building rockets. Got it home, opened the bag, was checking out the parts fit, and realized that the first fin I pulled out of the bag was pretty badly bent and twisted. Tried the rest. Two were eyeball straight, one other was visibly not right, although nowhere near as bad as the first.
Will measure everything up and memorialize it in an OR file, but glad I got it locally at brick and mortar. Much easier to return than if I had added a Phantom Blue (same rocket, just different colors and a shorter airframe) to my HobbyLinc order.
Will measure everything up and memorialize it in an OR file, but glad I got it locally at brick and mortar. Much easier to return than if I had added a Phantom Blue (same rocket, just different colors and a shorter airframe) to my HobbyLinc order.
I read another back issue of extreme rocketry 2006
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Might I ask for the STLs? Or the source files?
Nothing as fancy as most things I see on here. I started two new builds tonight. The first is a scratch build of an Estes Laser. A small BT-20 based kit. (#1938) Thanks to StickerShock23 I was able to get decals for it. The Laser was the first kit I ever built in sixth grade, so I kind of felt like it should be in my collection. It is basically done, I just need to find the correct nose cone for it. So far nothing in my parts boxes is right. The second is a Vander-Burn Big Daddy to Leviathan conversion. Again, thanks to StickerShock for the decals. This one will get modified with a payload bay so I can throw in a tracker and also not worry about the nose cone deployment troubles.
Sooner Boomer
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Sat on the couch, thinking. All but one of my high power rockets is broken. It's too cold to work on anything (epoxy - unheated garage). When it warms up, it will be: rebuild, or build new? I've got to "fix" the only nosecone that can hold a tracker. It got bent last time out (sudden stop at end of flight). I think I can heat it and bend it back into shape. I don't have another tracker sled holder to put into another nosecone, so I pretty much need to fix this one.
I'm getting depressed and frustrated with this hobby. Every launch costs a minimum of $50 (cost of a 38mm H reload). Boo-boos are extra.
I'm getting depressed and frustrated with this hobby. Every launch costs a minimum of $50 (cost of a 38mm H reload). Boo-boos are extra.
Except for fillets the plane is assembled. Ready to be added to the paint backlog. Tomorrow is supposed to be nice weather. I hope.
GrouchoDuke
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Just that document is an incredible amount of work. I'm hoping to not write an encyclopedia for my L3.
Figured out one way to make a conical nose with a rounded tip---like the Titan ICBM or the Shuttle SRBs---in OpenRocket. Make a solid conical transition, say 1/2" to 2". Forward end has no shoulder. Add a solid elliptical nose cone, 1/2" diameter and 1/4" long (or shorter as desired), no shoulder, to the 1/2" end.
No doubt there's another way. Need someone with more working brain cells than me, to figure it out. Five or six brain cells would probably do.
No doubt there's another way. Need someone with more working brain cells than me, to figure it out. Five or six brain cells would probably do.
Figured out one way to make a conical nose with a rounded tip---like the Titan ICBM or the Shuttle SRBs---in OpenRocket. Make a solid conical transition, say 1/2" to 2". Forward end has no shoulder. Add a solid elliptical nose cone, 1/2" diameter and 1/4" long (or shorter as desired), no shoulder, to the 1/2" end.
No doubt there's another way. Need someone with more working brain cells than me, to figure it out. Five or six brain cells would probably do.
That is the correct way to do it. It's the the best way to model FG nosecones with Al tips, too.
Doesn't that give you an undesirable corner? The sides of the elliptical nose at its base should be parallel to the axis, and the transition's sides are not. You can eliminate that corner by using a parabolic nose cone instead. It takes either some trial and error or fancy computation to get the position and diameter of the change-over just right so that the corner disappears. I've done the math and developed the formula in the past, but I may have lost it. I'll post the answer if I can find it or when I recreate it.Figured out one way to make a conical nose with a rounded tip---like the Titan ICBM or the Shuttle SRBs---in OpenRocket. Make a solid conical transition, say 1/2" to 2". Forward end has no shoulder. Add a solid elliptical nose cone, 1/2" diameter and 1/4" long (or shorter as desired), no shoulder, to the 1/2" end.
No doubt there's another way. Need someone with more working brain cells than me, to figure it out. Five or six brain cells would probably do.
Come to think of it, the math isn't that hard for parabolic on top of conical. What gave me a hard time was parabolic on top of ogive. That results in a nose cone that's parallel at the base and rounded at the top but slimmer than an elliptical of the same total length.
Printed a couple fin guides from The Payload Bay and got them glued to a piece of foam board. Now need to get one cut out to glue fins back on Fat Daddy for a launch this weekend.
At first I was upset that they broke free when the 'chute tangled last month, but the more I think about it, I'm glad they didn't break.
All I have to do is glue them back on. No buying plywood, no fabricating.
Maybe this time I won't bounce it off the runway.
At first I was upset that they broke free when the 'chute tangled last month, but the more I think about it, I'm glad they didn't break.
All I have to do is glue them back on. No buying plywood, no fabricating.
Maybe this time I won't bounce it off the runway.
Famous last words.
First try with custom decals and scrapped it afterwards, but I know what to do next.
I sprayed the plastic adhesion promoter on the nose cones, then the first coat of primer on the Crossfire, original fat boy, a Solar Explorer, and a baby Bertha. it's amazing how many defects show up with that primer.
That's basically what happens to greater or lesser degree on anything but a perfectly vertical, zero-speed apogee. Besides the chance of a zipper, there's the chance of the bottom of the rocket colliding with its nose cone or upper body (in the case of a conventional a dual-deploy) as it flies past the chute. (I have several very dented BT-70 balsa cones that can testify to that.)
A number of experienced rocketeers I know keep their drogues closer to the fin section than the rest of the rocket to avoid such a collision ("clacker"), and many build with a zipperless coupler to avoid the former problem.
@JimJarvis50 's "15k My Way" talk touches on both of these techniques:
In the end I was glad I bought my Olypuses from Hobby Lobby (not that they're sold elsewhere), since I was eventually able to find the receipts and exit from my brief BT-65 escapade with little damage.
Oh, I'm hoping you do write one. Will be fascinating reading!Just that document is an incredible amount of work. I'm hoping to not write an encyclopedia for my L3.
@K'Tesh used a very similar trick on his Der Big Red Max .ork, which I've cloned into my own DBRM designs and sims.
Got the fin alignment guide cut. Mixed some wood flour with Titebond III to thicken it and glued fins back on Fat Daddy.
Fillets tomorrow.
Fillets tomorrow.
I installed the 24mm motor mount in the Aspire today, added some launch lugs also. Going to use some D motors for 1400' and some E motors for 2000' flights.
I"ll order another one to use with the 29mm motors and the rail guides.
I"ll order another one to use with the 29mm motors and the rail guides.
The LOC Goblin got here in record time so I wasted no time getting the t-nuts installed in the main and adapter centering rings, then epoxy coated. Dry fit the rings and fins then tacked the centering rings in place. And of course filled the spirals cause I just LOVE sanding. I've never built the mmt and fins outside of the air frame then slid the assembly into the body tube. Time to learn by doing!
Not very interesting without pictures, but I did some sanding work on the molded FG fin can for a 4" Little John. I bought this used with the rear CR and Aeropacks retainer already attached to the motor mount, so I sanded that CR down for a better fit into the fin can. I've already attached the coupler and one ply CR at the forward end of the fin can.
Because it's a fin can and there's no TTW tabs, I laser cut stringers to replace those tabs and take some of the motor load off the CR epoxy joints. Going to attach them to the motor mount and get everything sanded up so it fits. Then I have rail buttons, the forward CR with recovery anchor, and epoxying the airframe onto the fin can and it will be ready for flying and/or finishing.
I'm reusing the nose cone from my cardboard L1 Little John (that a burn-through torched last summer) because the FG one that came with the kit is 5:1 and scale is 4:1.
Because it's a fin can and there's no TTW tabs, I laser cut stringers to replace those tabs and take some of the motor load off the CR epoxy joints. Going to attach them to the motor mount and get everything sanded up so it fits. Then I have rail buttons, the forward CR with recovery anchor, and epoxying the airframe onto the fin can and it will be ready for flying and/or finishing.
I'm reusing the nose cone from my cardboard L1 Little John (that a burn-through torched last summer) because the FG one that came with the kit is 5:1 and scale is 4:1.
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Just slit the end of the fin slot in the center. An extra pair of hands will be helpful when inserting the fins through the slots to keep from deforming them too much. I've built 3. Long story...
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Started building this NCR Lance Delta recently. Installed MMT and fins installed today.
Thank you Secret Santa 2020.
Thank you Secret Santa 2020.
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Should be here by Friday. I had to sell another eyepiece to afford.
Sanded on 3 rockets I put primer on today.
Not a problem. Be advised it ships in 2 cartons.
I've had to chuck mine at the back of the build pile while I slog through an L3 project.
Cheers
GrouchoDuke
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Well, I caved and decided my L3 cert will just be a 4" rocket with a 13-15k flight. I really wanted to do an M-motor Mach 3+ record attempt for my L3 cert, but my quick (and admittedly incomplete and encyclopedia-lacking) survey of TAPs didn't give me a warm fuzzy that I could find 2 to sign up for that. My L1 & L2-level record attempts this year are going to trump my L3 attempt though...and I haven't started looking for TAPs.Oh, I'm hoping you do write one. Will be fascinating reading!
Anyway, the flight I'm planning is pretty vanilla & shouldn't require an encyclopedia and wouldn't be an interesting read even if it was.I still feel like I'm giving up since I've sent H, I & J motors higher than my L3 cert is planned. It should still make for some cool photos though.
As far as "what did you do rocket wise today," I ordered some more PCBs for some electronics I'm working on. A day or 2 ago, I also ordered some parts I needed for a new rocket I'm designing.
Just adjust the length of the elliptical nose until the corner is gone.
I'm happy that works for you, but I don't understand. How could there possibly not be a corner?
EDIT: Here is is with a parabolic tip (fit by trial and error):
EDIT: Here is is with a parabolic tip (fit by trial and error):
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