CJ's Space Cowboy build manual.....you asked for it!

Finally caught up with stuff and as promised the Wildman Space Cowboy. I'm building one right now. This will incorporate methods of low drag av-bay installation used in LDRS 30 challenge. { which by the way, it just happened to win! lol}
There's a bunch of them getting to new owners in need of "how to".

Borrowed the parts pic from BsSmith since he did such a nice job.

Here we go!

.....54mm Minimum Diameter Dual De-ploy High performance WildMan Space Cowboy......

This newly released kit is the next step up from the BlackHawk minimum diameter series and now fills that 54mm void.
Almost 100 bucks cheaper than a MonGoose 54 & with better performance!

This is the only kit being sold today with high performance diamond airfoiled fins. With medium sized 38 & small 2 grain 54 motors it will reach altitudes over 8,000ft..[with rail buttons!] With large 54's 20,000 ft. + altitudes, are easily attained. [with tower]

Numerous simulations & testing determined the final fin size & shape. This rocket is not for the faint of heart. This ones the real deal & some previous build experience is recommended. Mach 2 + flights are expected with no more than the recommended fillets. No tip to tip or carbon is needed. With the smooth interior of the Spiral wound cone there is plenty of room for GPS & electronics. No Carbon, No transmitting block out for trackers & GPS/Telemetry!
Glue it up, stick the biggest motor ya got in it & put it on the pad. So get ready to punch a BIG hole in the sky.

All spiral wound G-12 tubes and NC.
G-10 plate .125 airfoiled machined fins

Fincan 54mm tubing 34 in.ish
Payload 54mm 16in.
Von Karmon NC 5 to 1
1 6in. av-bay coupler
1 4in. NC coupler/shoulder

2 black anodized aluminum BP's
Both threaded for 3/16 eyebolts.
1 BP threaded for 2 tie rods # 6 allthread.
1 BP smooth bore holes for 2 tie rods.

2 threaded [#6] ejection charge holders. Screw on tie rod. Capacity approximately 1.5grams
1 set Tapered Fin guides [2]
Black High Temp epoxy kit [resin/hardener]

WARNING.......ATTENTION...........DANGER.......DON'T DO IT!!
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DO NOT ADD ANYTHING repeat ANYTHING to the epoxy. It will NOT strengthen it, but will only destroy it's full potential.
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3.2 to 3.5 lbs built ready to fly with everything sans motor as built here. [depending on use of 1 or 2 altimeters, trackers etc.]

For Maximum Performance & Altitude use a tailcone closure on motor.

Note:It's not a JR. that's just the graphics supplied to me. [Jr's are 38mm motor mounts] This will NOT come that way so don't ask LOL.

First off let me say:

Many would be owners of this are experienced enough and more than likely to modify this kit to suite their own Extreme needs. These instructions will seem boring or mundane for you. I expect this kit to be seen in many forms built to the standards of individual flight requirements.

But for those in need............


First thing is mod the guides so when tacking on the fins you don't glue them to the airframe.

[The multi-sided ones come with the kit. I will be using my ole proto type set [square ones]from my first build]

Knock off the corners of guide with file or sandpaper [so glue oozing out from under the fin, during the "tack on" process clears the guides.]
Clearly seen on my "square" ones.


Nose Cone assembly.
PDF for nose cone below.

Mark 1 1/4 inch from edge of tube for fin position.

Draw circle around airframe for guide position.[ to keep rear fin edges equal distance from tube end]

Slide fin guide into position on airframe and mark for all 3 fins.

[Note: I had a pre-made marking wrap from another build.To get it on I had to slip it over the tapered NC I stuck in tube. that's why it looks funny]

Extend the lines at least as long as the fins.

Sand on each side of line 1/2 inch for fillet adhesion.

Use 80 grit or larger for this. The rougher-gouged up it is the better.

These fins require over 1,000 steps in the machining process to get the foiled diamond shape. This leaves a slightly grainy finish. A very light sanding with 150 or greater will remove most of this. DO NOT OVERDO IT or you may DESTROY the FOILED SHAPE. It is better to wait till finishing and a coat or 2 of paint will take care of it.
The funny wavy lines on the sides of fins are just different layers of G-10 being exposed from the process, much like the exposed layers of ply when beveling wood fins.


About 3/8 in. of root edge is left squared full stock, for fillets. Bevel front and rear edge.

Fin edges are well foiled but are blunt. If you desire shape the last 1/8.in also. [outlined in black]

To expose a greater surface for glue adhesion on root, use a V-file, hacksaw blade or edge of reg. file and put several V-grooves at a slight angle across the root.

Not too deep about 1/8in. or there about.

A few swipes on bottom & sides of full stock area on fins with 80 grit to aid in fillet adhesion.


Note: Edges were outlined with black marker just for visual aid in photo. Last photo is raw fin.

Gouge area for fin with hacksaw blade or similar.

Set up tube and guide for a dry fit/run before tacking fins on. Make sure area is level , front of tube is supported and guides are not loose. Tape may be needed on tube so guides are snug.

Never thought of notching the base of MD fins like that--interesting idea. Would it make sense to make a pattern for additional strength in different directions, like perhaps an "X" pattern cut? Kind of like laying up CF weave in different directions.

Leave it to CJ--he just come up with the simplest and most amazing techniques!

Finished tacking the 6th fin on today.
I did them one at a time rather than my usual "all at once".Guess I'm getting mellow in my old age.

A bit of waiting for things to cure well & on to the High Temp fillets tomorrow.

One other lucky fellow gets one. [Shouldn't bet on football, note to self]

Fillets.

Doing this correctly is crucial. It's the only thing holding your fins on during Xtreme flight!

Must use a large diameter tool[dowel,pvc pipe. etc] for pulling fillets.
Recommended 1in. or larger. Here we use 1in exterior diam. PVC pipe section.

Tape off each side of fillet. To mark use a Sharpie & coat the end of dowel edge, rub back/forth in the V-groove to mark edges for tape, rolling while sliding. It may take a few times coating with Sharpie.
When pulling smooth, excess epoxy will come off when you remove the tape. No muss, no fuss!

Tape outer edge of lines.

Set up the good ole manual scales of yesteryear. Whens the last time ya saw one this old.Lol

Use 11 grams Black High temp epoxy.
2 gram Hardener.

13 total is more than enough for 2 fillets [1 set]

DO NOT ADD ANYTHING TO IT.... NO FILLERS OF ANY TYPE as per manufacturers specs. It already contains the needed fillers!

Mix for 1 minute scraping sides of cup, this black epoxy is gooey & stiff you must mix thoroughly for small amounts like this.

After finishing I weighed the surplus and had 4.8 remaining if you wish to measure and cut it closer, but I suggest doing the first set as recommended. Then measure what you have left. It's hard to account for what sticks to sides of mixing cup.

Pour epoxy into V-grooves and distribute evenly. Then pull out the fillet with one smooth even pressure motion.

blackjack2564 said:

One other lucky fellow gets one. [Shouldn't bet on football, note to self]

Click to expand...

Bet you the Giants walk away with the championship

Make sure your fincan is level and let fillets flow out & set.

Remove tape 10-15 minutes later. This lets the edge flow out so there isn't a ridge at the tape line.

If you wait till cure it becomes very difficult to remove tape, it will become bonded to fin at edge.

I can't wait till I get my Space Cowboy. op: I received it on Friday looks good. Oh by the way who go the job of licking all of the stickers?

I gotta get one...maybe shorten it a little, I've got a trick or two up my sleeve (that work in theory :tongue

Maybe give ya a run for your money! :wink:





Braden

I'm catching up Jim!!

Hey, bring that thing with you, if you make it to Thunderstruck.

Looking forward to see how you set up your av bay/sled attachment.

Couple days to sand the fillets to shape yeilded excellent results.

They came out very symmetrical.

Hey Jim, how thin do they get at the leading and trailing edges? :O

Hey Jim, Jason, bring those things to Thunderstruck, I've got a little 2" carbon rocket and a K-2045. You guys up fo a little drag race?

Manny

Rather than primer I opted to use 1500 degree header paint. Several light coats, then a very light fill of spot putty to fix heavy sanding marks and a few flaws in the fillets.

Dry overnight and wet sand with 400 to a nice polish.

Even got the nice little "hook' on the rear end of fillet i was after.

Interior view shows the fairly substantial size to the fillets.

Alll this went much faster than the first time around for LDRS

edwinshap1 said:

Hey Jim, how thin do they get at the leading and trailing edges? :O

Click to expand...

See drawing in first post. fins start out as 1/8in stock.

mannyskid said:

Hey Jim, Jason, bring those things to Thunderstruck, I've got a little 2" carbon rocket and a K-2045. You guys up fo a little drag race?

Manny

Click to expand...

Be there or be square.oint:

Related to this build/design is a great article on Airfoiled Fins in the latest Apogee Rockets newsletter: https://www.apogeerockets.com/education/downloads/Newsletter305.pdf

mannyskid said:

Hey Jim, Jason, bring those things to Thunderstruck, I've got a little 2" carbon rocket and a K-2045. You guys up fo a little drag race?

Manny

Click to expand...

I'm in!!

I would really like to see someone build two of these models: one with the air foiled fins, and another with just the leading and trailing edges coming to a point. Then drag race them on identical motors and see whether or not the performance difference is significant.

I'd be willing to bet that you are looking at a very small performance improvement, if any. Proving me wrong would be fun, too.

I got 200 bucks on CJ's fins...

patelldp said:

I would really like to see someone build two of these models: one with the air foiled fins, and another with just the leading and trailing edges coming to a point. Then drag race them on identical motors and see whether or not the performance difference is significant.

I'd be willing to bet that you are looking at a very small performance improvement, if any. Proving me wrong would be fun, too.

Click to expand...

the difference will be significant enough to be noticable, but not by a huge margin. If the propellant filled up the entire body tube and the rocket were going very very high/fast i'd say you'd get a very noticable difference.

Altimeter Bay:

Kit comes with a 6in coupler.
2 stepped aluminum BP's.
Threaded for 3/16 eyebolts.
1 BP has threaded holes for # 6 allthread.The other smooth holes.
Both have 2 holes for E-matches.
2 Aluminum ejection charge holders. [approximately 1.5 grams] threaded to go on tie rods.

There are many ways to install Av-bays on high performance rockets like this & many fliers will have their own tried & true methods.

There are 2 basic attachment methods addressed here.

1. you need 2 plastic rivets & 5/32 drill bit to install.

2. no drag attachment for high performance flying, used in the LDRS First to 10,000 feet version.
The BP's also have threaded holes in sides, spaced for either 3 or 4..... 2-56 screws to hold bay in.They can be mounted flush with airframe. I use 3 stainless steel cap head from Mac-Car. Drill bit #47 for screws & #29 bit to recess them in airframe.

Both ways need # 6 all thread + nuts. 2 - 3/16 eyebolts and 2 nuts each.

First measure & mark 1/2 of coupler.
Insert into payload and mark circumference of coupler.

By the way, one of the issues airfoiled tapered fins address is fin flutter.

By having a thinner tip than the root... due to the tapered fin, you reduce the resonance harmonics that contribute to flutter, which is more prevalent in fins with same thickness through out & just beveled or rounded over on the edges.

David Reese ran tons of specialized computer sims on the thickness, shape and taper over a wide variety of motors to come up with this optimized design. I sure if he is following this he'll step in and give ya the "scientific" angle to this. He has access to programs we can only wish for.

It was not something I drew that I thought looked good or guessed at.

Install eyebolts into threaded center holes on BP.

Nut on each side.

Cut off excess rod on bolt and de-burr.

Install # 6 threaded rod leaving 3/8 to 1/2 in. on each end for ejection charge holders.

I just screwed them in and did my cutting on one end.

The standard av-bay installation is 2 rivets 180 degrees from each other.

Measure 1.5 inches from edge of tube and mark.
Install coupler to halfway mark & drill hole with 5/32 bit and install rivets.

For high performance I will use 3 stainless 2-56 cap head screws.The BP is tapped for 3 or 4 hole installation.

Place BP into coupler and slide into payload to the halfway mark.

Shine flashlight into coupler to illuminate the holes. [works better if you slide lite into coupler about 1/2inch from BP]

Mark hole, remove coupler/BP & drill hole with #47 .0785 diam or [5/64 .0781 may have to ream a bit]
Install screw to check for fit, and mark next position.
Removes screw & coupler/BP & drill 2nd hole.

Repeat for 3rd.