L3 4 Inch Black Brandt Scratch Build *Success*

Had these things hanging out on my bench for a while.

I have been debating on turning it into my level 3 bird but I think ill stick with some Ls for now.

Now the good stuff filament wound carbon tube. Scotglass nose cone. Still working on the fins might do plywood might do carbon. Will be setup for DD




I am hoping that by posting here it will motivate me to get to work.

What tow size is that? It just makes the tubes magnificent.


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

I am watching to see your expertise.

SinfulDarkLord said:

What tow size is that? It just makes the tubes magnificent.


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

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Its multiple tows

flynfrog said:

Its multiple tows

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Got a closer look and yeah I can see the multiple tows. Thats interesting and awesome.


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

So this came in today.


Ive been talking to my TAP team about getting my level 3.


Currently hung up on recovery. I was originally planning on a cable cutter so I could use my telemetrum and a raven in the nose. It was suggest by my TAP team to look into a more conventional dual deploy setup using a deployment bag. This will be a some what high flight ~15 so I dont want to go without the tracker.

I do have a few ravens I could do a dual deploy out of an av bay and leave the telemetrum in the nose for tracking only. this does make it a some what more expensive flight if it all goes wrong. On the other hand one raven is pretty minor by the time you add in the motor case.

The concern being that using a cable cuter you add extra shock into the recovery stack since you don't allow the chute lines to go tight before deployment like you would with a bag.

I have thought about using some sort of tether as well but I was warned against the risk of tangling.

Thoughts?

I'm not convinced that the shock argument is a valid reason to change deployment schemes. D-bags were intended to be used under tension, not fired randomly into the airstream, as in a standard DD setup. They are useful to keep things orderly and neat, (and yes I have used them) but from what I have observed they aren't actually doing much in the way of reducing the loads at deployment when used in this way.

So I would just go with whatever you feel comfortable with, but I guess you are at the mercy of your TAPS.

Go with what you feel the most comfortable with . The first flight maybe your L3 attempt . While there are a number of "new" things that you can do for a cert flight , a new recovery deployment design should not be one of them .

Eric

To clarify the dual deploy would put out a pilot first to pull the bag off.

I also got some fins cut today






And a gift from Loki Research

Big thanks to Scott, His service is outstanding. The machine work on the case is jewel like.

Wow. I've got some serious workshop envy going on. Awesome project. I saw that tube you gave to Jim Y at a launch a few months ago. Blows all those ground finish carbon tubes out of the water. When were you planning on flying?

Alex

The cnc is not mine Should go up for Hellfire.

got the fincan done with the motor mount. Im going to throw some plies at it to get the flutter speed up with the swept fins.

Centering rings


266 grams of the good stuff


Sanded prepped and masked



Fillets done tape to hold everything in place.



Cured up going through QC

PS any TAP planning to attend Uroc Hellfire? My TAP witness has a schedule conflict.

That's looking sweet! Also nice motor pick, that's exactly the motor I'm using for my L3.

flynfrog said:

PS any TAP planning to attend Uroc Hellfire? My TAP witness has a schedule conflict.

Click to expand...

That's one of the main reasons I decided to go out to Aeronaut. It's on the same weekend and I know there will be TAPs out there. Black rock is a bit of a drive though.

SEE! I told you guys black brandt was spelt with a D...

Nice build!!

I hope there will be a TAP at Hellfire. I'm hoping for L3 on my 6" Black Brant II.
-Ken

Wow is that a beautiful build....
That tubing is gorgeous....
So is the fin material,,,
So is the fin shape.....
Talk about shop tool envy....lol....
You used a CNC machine to cut out the fins ???
No fair...lol....

Super cool...
I wish you were closer so I'd get to see the flight....
Good luck with everything....

Teddy

Beautiful could be an understatement. I've personally touched some of his stuff. No words to describe! It's just so awesome!
-Ken

Thanks for all the complements. Hopefully I get some time this week to turn down the couplers as my tubing is not quite 4in. I have a mcmaster order ready to go for most of the hardware.

Turned down the couplers today. First time all of the parts have been fitted together.

Waiting on my hardware order to finish up the av bays and test but it was good light today so why not take another picture

Looks great! Good call on replacing that NC. I'm really loving the FWFG conicals.

Alex

How did you get the winding pattern on the tube to show up so clearly? Very smooth clearcoat? It looks really good.

The tube isn't ground its just the surface resin.

where did you get the nose cone?

My biggest concerns are with the large aspect ratio of the fins. If you plan on pushing that little rocket with an M motor I guarantee that the fin flutter demon will bite you. I would go with a couple of layers tip to tip with carbon. Stagger the layers so they are not covering exactly the same. Anything to break up the harmonics. What exactly are the fins made out of? Layers? Weight? Epoxy? Etc?

BayouRat said:

My biggest concerns are with the large aspect ratio of the fins. If you plan on pushing that little rocket with an M motor I guarantee that the fin flutter demon will bite you. I would go with a couple of layers tip to tip with carbon. Stagger the layers so they are not covering exactly the same. Anything to break up the harmonics. What exactly are the fins made out of? Layers? Weight? Epoxy? Etc?

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Its a secret 😋.

Zebedee said:

where did you get the nose cone?

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Rocketry Warehouse

BayouRat said:

My biggest concerns are with the large aspect ratio of the fins. If you plan on pushing that little rocket with an M motor I guarantee that the fin flutter demon will bite you. I would go with a couple of layers tip to tip with carbon. Stagger the layers so they are not covering exactly the same. Anything to break up the harmonics. What exactly are the fins made out of? Layers? Weight? Epoxy? Etc?

Click to expand...

Fins are intermediate modulus 3k PW with a prototype nanocomposite resin system we were working on for composite tooling It has a low very low CTE and and is very hard. I think 12 plies but its been a year since a laid them up. I will need 3 layers of t2t of 3kPW a side to get out of flutter territory

BayouRat said:

My biggest concerns are with the large aspect ratio of the fins. If you plan on pushing that little rocket with an M motor I guarantee that the fin flutter demon will bite you. I would go with a couple of layers tip to tip with carbon. Stagger the layers so they are not covering exactly the same. Anything to break up the harmonics. What exactly are the fins made out of? Layers? Weight? Epoxy? Etc?

Click to expand...

Ditch the D-bag and be a Burrito Boy for the main chute. Get the L3 and then go with the D-bags.....................Unless of course you've flown with a lot of D-bags and already got the deployments down pat.

I've had a chute hang in a D-bag so I'm 1 for 2. The failure was due to a "downsized" pilot chute on the bag and my "success" was sort of a Hail Mary. I used to pooh-pooh the B2 Rocketry technique of putting the nosecone on the D-bag with its own smaller chute and using the mass of the nosecone to yank the D-bag off the chute. Nosecone/D-bag comes down on its own chute and the heavier sustainer comes down on its own larger chute. I'm thinking theirs is a better idea now.

If one uses too large a drogue and too small of a pilot chute on the D-bag (for a conventional DD) the rocket might not be "falling" fast enough for a "too small" pilot chute on the D-bag to pull the bag off the main.
That was my failure. The rocket streamered in nicely with the main still stuffed in the bag and landed in soft dirt but no damage. It was a LOC cardboard tubed rocket too. No reinforcement so that was a lucky break.

Go simple if that's what your TAPs recommend. Kurt