BlackJack's 54mm LDRS project, true diamond air foiled fins. Space Cowboy!

If you saw this thread....
https://www.rocketryforum.com/showthread.php?t=17743 ... it was the prelude to my minimum diameter 54 LDRS project.

I'm building this with standard G-12 tubing & parts, including a Von Karmen NC. [ the new spiral wound G-12 one]

Thanks to Daveyfire for doing all the sims and drawings of the fins. Even a 3d cad file. As you will see these are true airfoiled fins.

Also thanks to Eric of Badazz R. for transforming the design into reality. He machined these bad boys!
I'm going out on a limb and NOT tip to tip or re-enforcing them in any way. Just using Pro-line high temp epoxy [the black stuff] & big honking anti-aircraft fillets.

Don Ball designed the fins for me after much research and simming also.

This build is the result of finding the best of the best to bring my ideas into reality for what I think will be a real winner. It will fly high or be spectacular either way!
I always thought carbon was overkill for this type of rocket & the Kestral proved that, so this is my version of pushing the limit.

View attachment CJ54Fin-AF - Sheet1.pdf

Fins started out as 1/8in. G-10 stock.

Machined from the root edge leaving a full stock thickness for a 1/4in. up to have some meat for the fillets to bond to.

You can see the layers shaved off from the center to the leading and trailing edges.

Standing on end, the taper is readily apparent.

And as much material has been removed, they still are extremely stiff.

The last pic after hand sanding the tapers in the leading & trailing root edge, notches filed in root edge for better glue bonding

Eric also supplied me with a set of perfect fin guides, notice the slots are even tapered to match the fins!

The fin can started out at 36inches. But has been stretched to 54in to accommodate the 36inch single use L-350 long burn [10 seconds] that Tom Binford is designing and building for this extreme flight.

Payload will be 16 in. and a 7in coupler with aluminum stepped BP's with built in groove and O-ring to seal it up tight.

It will be held in the payload by tapping the BP on the forward end [edge]for 3 4-40 allen screws the will flush mount[the heads] on the airframe and screw into the side of couple and BP.

Jim Jarvis has graciously agreed to test my ejection charge ideas in his vacuum chamber. That in itself will be very interesting to see the final results. So for once I'm doing the science behind a project and not just "going crazy" LOL

So you can see this is truly a group effort, getting the best out there with their expertise in each's own field. Tim at Wildman's is supplying the tubes & glass stock needed.

So this is how it's starting out, but by the end it could be drastically different bird. Going to let form follow function totally on this one

Custom spiral wound G-12 Von Karmen NC next to glass one. Tad longer with more taper.

Started by tacking fin on with a healthy dose of JB. weld.

Careful not to "push" out all the glue. These babies need to bond good with what I'll put them through.

Mounted 1 1/4 in. from edge of tube.

if the giant fillets work out, i will be filleting everything

i seroiusly can't wait to see how this build develops. how are you going to paint it do you think?

This should be interesting to see. What kind of altitude are you expecting?

edwinshap1 said:

if the giant fillets work out, i will be filleting everything

i seroiusly can't wait to see how this build develops. how are you going to paint it do you think?

Click to expand...

Well they're not going to be THAT big, just beefy! Don't have to be, the fins are sharp as razors and stiff as steel.
It's only getting enough paint to fill in imperfections.

A very light coat of my 2 colors orange/blue to aid in finding it.

Then wet sanded with 600 & left alone. Basically a polished finish. Smoother than any painted one.

Won't be pretty, but that's not the point! LOL.

cjl said:

This should be interesting to see. What kind of altitude are you expecting?

Click to expand...

Have to build a test motor first, then the data can be added to a file & simulated. Hopefully over 25,000. But it's gonna be long, so it may be diminishing returns. I'll get Tom to pitch in with some motor data. There's a few hurdles to overcome. He wanted to do a 54mm M, but I chickened out & settled for the L.

I'm also planning another area 51 flight. D-grain N-800 in a 98mm minimum 10lb. rocket.

16 sec burn, around 36,000ft if all goes well. If I get a larger case[6g xl] it will be a longer burn. LOL Heck I'll be happy with anything over 30!

But first things first. Got to get this one done.

Have you heard about the N-5800 C-Star drag race in Ultimate Wildman's? Somewhere in the 20,000 ft range. I think there are 11 in so far. MWP-9

blackjack2564 said:

Have to build a test motor first, then the data can be added to a file & simulated. Hopefully over 25,000. But it's gonna be long, so it may be diminishing returns. I'll get Tom to pitch in with some motor data. There's a few hurdles to overcome. He wanted to do a 54mm M, but I chickened out & settled for the L.

I'm also planning another area 51 flight. D-grain N-800 in a 98mm minimum 10lb. rocket.

16 sec burn, around 36,000ft if all goes well. If I get a larger case[6g xl] it will be a longer burn. LOL Heck I'll be happy with anything over 30!

But first things first. Got to get this one done.

Have you heard about the N-5800 C-Star drag race in Ultimate Wildman's? Somewhere in the 20,000 ft range. I think there are 11 in so far. MWP-9

Click to expand...

I can't believe you passed on the M motor! Go Big or Go Home
Thanks for the shout out!!! I have to get a web page done. New kits coming Soon. I plan to debut them Here on TRF.:clap:

Jim...

What's your projected final weight? If you're not sure, what do the components themselves weigh?

Final weight will be a big factor in the altitude. Little things, like using a tailcone closure on a Pro54, as opposed to the standard closure, start adding up, as well.

A friend is a bit of a performance junkie, so we hand-rolled a CF tube for his latest creation -- totally prepped, everything but motor, it weighs 2.5 pounds.

-Kevin

Jim - This build looks awesome! I enjoy watching Tom's long burn motors, very smooth burns.

CJ,

Awesome build. I hope you video the launch. I can't wait to see it.

Those fin guides look awesome. I can see a market for them.

cwbullet said:

CJ,

Awesome build. I hope you video the launch. I can't wait to see it.

Those fin guides look awesome. I can see a market for them.

Click to expand...

Couldn't agree more, I would have bought a pair for the Intimidator 3 I just finished filleting...fins are "close" but still make me cringe when I think about them not being perfectly aligned...

This is a great thread for an aspiring altitude junkie. Hope all goes well. I see that you are using a Von Karmen nose cone, so that means this rocket will be traveling most of the time in the transonic? Quick question, how are you going to attach the nose cone?

Jim
Looks good man, I'm guessing the beer to epoxy ratios are high on this one..

troj said:

Jim...

What's your projected final weight? If you're not sure, what do the components themselves weigh?

Final weight will be a big factor in the altitude. Little things, like using a tailcone closure on a Pro54, as opposed to the standard closure, start adding up, as well.

A friend is a bit of a performance junkie, so we hand-rolled a CF tube for his latest creation -- totally prepped, everything but motor, it weighs 2.5 pounds.

-Kevin

Click to expand...

Fins are on & weight so far is 2.6lbs. Bear in mind that this thing is looong due to the single use 36in motor. Right now total length is 77inches.!

I will probably cut the fincan down to a more reasonable length [36] for flying commercial motors after this flight. [if I get it back LOL]

Yes I have molding a tail-cone into the motor as part of the plan. I do have the CTI tail cone retainer for flying their motors. If you have one hang onto it. They are no longer making them.

Weight can't be helped due to length, but with this large motor may actually help during coast. Predicted is 3.75 lbs in this configuration.

I don't have the capability to hand roll my own carbon yet & wanted to do this with off the shelf stuff. If this performs well, a little birdie tells me fins like this could become available, separately or maybe even in kit form. They won't be cheap, but then performance at this level never is.

cwbullet said:

CJ,

Awesome build. I hope you video the launch. I can't wait to see it.

Those fin guides look awesome. I can see a market for them.

Click to expand...

Oh, I wouldn't be surprised If Eric has already thought about that, as well as many other goodies he has in area 51.
If he hasn't, he should!
But I will have to let him respond to that. He certainly has the capability to make them for any project or size. Nice to get them on really straight.

If you ask him nicely he may............

Cyril's Scribe said:

This is a great thread for an aspiring altitude junkie. Hope all goes well. I see that you are using a Von Karmen nose cone, so that means this rocket will be traveling most of the time in the transonic? Quick question, how are you going to attach the nose cone?

Click to expand...

For the L flight it should barely be near mach for most of the thrust phase.


Attach NC to what?

Shear pins cut flush to hold it in payload.
1/4Kevlar loop glued onto shoulder to attach recovery gear.

This what you meant?

blackjack2564 said:

Fins started out as 1/8in. G-10 stock.

Machined from the root edge leaving a full stock thickness for a 1/4in. up to have some meat for the fillets to bond to.

You can see the layers shaved off from the center to the leading and trailing edges.

Standing on end, the taper is readily apparent.

And as much material has been removed, they still are extremely stiff.

The last pic after hand sanding the tapers in the leading & trailing root edge, notches filed in root edge for better glue bonding

Click to expand...

Very nice!

Were these fins CNC machined?

Greg

blackjack2564 said:

Yes I have molding a tail-cone into the motor as part of the plan. I do have the CTI tail cone retainer for flying their motors. If you have one hang onto it. They are no longer making them.

Click to expand...

Good to know. I'll definitely keep mine.

Weight can't be helped due to length, but with this large motor may actually help during coast. Predicted is 3.75 lbs in this configuration.

Click to expand...

Unless there's a huge difference between the motor you use and the Pro54-6XL loads, you're probably at least a pound heavy. On the one Nate made, optimal mass is actually a little bit below the 2.5lbs his weighs.

I don't have the capability to hand roll my own carbon yet & wanted to do this with off the shelf stuff.

Click to expand...

Yeah, hand-rolling tubes is a pain in the posterior. It took us a few tries to get good at it. Rolling the tube is the easy part. Getting it off the mandrel is what really sucks! :eyepop:

If this performs well, a little birdie tells me fins like this could become available, separately or maybe even in kit form. They won't be cheap, but then performance at this level never is.

Click to expand...

That's cool, and yeah, I can understand those fins not being cheap - there's a lot of machine time in creating the shape.

It's a cool project, and I'll be curious to see how it performs. At LDRS, I'll have to have Nate show you his little screamer.

-Kevin

blackjack2564 said:

Have to build a test motor first, then the data can be added to a file & simulated. Hopefully over 25,000. But it's gonna be long, so it may be diminishing returns. I'll get Tom to pitch in with some motor data. There's a few hurdles to overcome. He wanted to do a 54mm M, but I chickened out & settled for the L.

I'm also planning another area 51 flight. D-grain N-800 in a 98mm minimum 10lb. rocket.

16 sec burn, around 36,000ft if all goes well. If I get a larger case[6g xl] it will be a longer burn. LOL Heck I'll be happy with anything over 30!

Click to expand...

Sounds awesome. I'm definitely looking forward to seeing this one go up.

blackjack2564 said:

Have you heard about the N-5800 C-Star drag race in Ultimate Wildman's? Somewhere in the 20,000 ft range. I think there are 11 in so far. MWP-9

Click to expand...

Oh yes. I may have to come out to MWP just to see that. I've got an N5800 to fly this Saturday, and that'll be my first time seeing the motor. 11 of them at once would be incredible though.

troj said:

Yeah, hand-rolling tubes is a pain in the posterior. It took us a few tries to get good at it. Rolling the tube is the easy part. Getting it off the mandrel is what really sucks! :eyepop:
-Kevin

Click to expand...

bacon grease no joke, i made my first attempt and the tube wouln't pull off, so my dad told me to grease the mandrel before wrapping. well believe it or not, bacon grease is one amazing lubricant. i wouldn't recommend it for an engine since it does have a realtively low flash point compared to the sythesized lubes

edwinshap1 said:

bacon grease no joke, i made my first attempt and the tube wouln't pull off, so my dad told me to grease the mandrel before wrapping. well believe it or not, bacon grease is one amazing lubricant. i wouldn't recommend it for an engine since it does have a realtively low flash point compared to the sythesized lubes

Click to expand...

Anything we use has to be able to take 200F and a lot of pressure, without getting squeezed out. I suspect bacon grease wouldn't meet those requirements.

-Kevin

troj said:

Anything we use has to be able to take 200F and a lot of pressure, without getting squeezed out. I suspect bacon grease wouldn't meet those requirements.

-Kevin

Click to expand...

hmm, a thin coat, as long as the pinching? material pinched down pretty evenly i think that even if it were to go into liquid form, it wouldn't be squeezed out. i'd say give it a try

blackjack2564 said:

Have to build a test motor first, then the data can be added to a file & simulated. Hopefully over 25,000. But it's gonna be long, so it may be diminishing returns. I'll get Tom to pitch in with some motor data. There's a few hurdles to overcome. He wanted to do a 54mm M, but I chickened out & settled for the L.

I'm also planning another area 51 flight. D-grain N-800 in a 98mm minimum 10lb. rocket.

16 sec burn, around 36,000ft if all goes well. If I get a larger case[6g xl] it will be a longer burn. LOL Heck I'll be happy with anything over 30!

But first things first. Got to get this one done.

Have you heard about the N-5800 C-Star drag race in Ultimate Wildman's? Somewhere in the 20,000 ft range. I think there are 11 in so far. MWP-9

Click to expand...

Stuff a 54/3300 L3000 in tha badboy........

edwinshap1 said:

hmm, a thin coat, as long as the pinching? material pinched down pretty evenly i think that even if it were to go into liquid form, it wouldn't be squeezed out. i'd say give it a try

Click to expand...

Why? There are plenty of perfectly good mold-release agents, and many of them aren't very expensive.

cjl said:

Why? There are plenty of perfectly good mold-release agents, and many of them aren't very expensive.

Click to expand...

because my family makes bacon, and we keep the grease around for cooking, and it's therefore free? lol

and it makes my copper pipe i use smell all yummy like breakfast

Ok, I can take a hint. Try to be patient, I will produce the fin guides!
29,38,54 to get it going.

I have to get my kits finished.
A photo shoot going for web design.
Instrucktions wriiten ( pun intended)
PayPal straightend out.

This a ton of work! Most fun I've had in years

What's this I hear that there's a special component to this rocket? Something about it costing you a pound of flesh? Or was that thumb....?

-Kevin

GregGleason said:

Very nice!

Were these fins CNC machined?

Greg

Click to expand...

Yes, how and the exact process I will have to let Eric explain as he made them for me.

Got a picture of that machine with a fin in it Eric? I sent him the file & he tweaked it so machining was possible. As usual what looks good on paper, doesn't always


Ummmm Troj....Just a little skin. I'm building a rocket, what do you think? Sooner or later CA will be involved. That d@^^ed Lehr filled the debonder bottle with CA. With friends like him, be careful, VERY careful.

He probably used to pull wings off of flies, tortured rats and god only knows the terrible , horrible, mean things he does to rockets! :y: