Project Hurricane is a go. L2 Re-Attempt. Mac Performance Firestick XL. 100% Composite Materials. (Build Thread)

[Orien]

I’ve learned a lot since my disastrously ambitious L2/Maiden Flight fiasco. Might as well apply that knowledge while it’s fresh, amiright?

Mac Performance Firestick XL

FEATURES: fwfg nosecone with aluminum tip, fwfg boattail, motor retainer, canvas phenolic fins and airframe.
ELECTRONICS: RRC2L (with external ARM switch), Marco Polo tracking unit, camera.
RECOVERY: Dual-Deploy

 

[Orien]

My three favorite words to see in my inbox: Out. For. Delivery.

 

[Banzai88]

MAC's canvas phenolic is a nice material, and his machining is second to none. Loved the build I did on 3" Scorpion . Prep for assembly is just like fiberglass in terms of scuffing the surfaces. As for finishing, prepare yourself with several cans of filler primer and 600 grit wet/dry sandpaper and it'll finish up as smooth as fiberglass.

Good luck, enjoy the build, and this time, choose a 'reasonable' motor

 

[Orien]

MAC's canvas phenolic is a nice material, and his machining is second to none. Loved the build I did on 3" Scorpion . Prep for assembly is just like fiberglass in terms of scuffing the surfaces. As for finishing, prepare yourself with several cans of filler primer and 600 grit wet/dry sandpaper and it'll finish up as smooth as fiberglass.

Good luck, enjoy the build, and this time, choose a 'reasonable' motor

I'm already over $100 for the paint job I want to do WITHOUT primer and clear coat. Why so much filler primer? Can you see the weave on the surfaces?

I am definitely selecting a more reasonable motor. "If this stuff is six times stronger than cardboard, then that's six times the motor. Oh wait, that one failed though. So FIVE times the motor. For safety."

 

[Banzai88]

I'm already over $100 for the paint job I want to do WITHOUT primer and clear coat. Why so much filler primer? Can you see the weave on the surfaces?

I am definitely selecting a more reasonable motor. "If this stuff is six times stronger than cardboard, then that's six times the motor. Oh wait, that one failed though. So FIVE times the motor. For safety."

It all depends on the particular run, but I've had pieces that showed the weave after many coats and reasonable sanding. Some pieces will drink it in and fill in nicely, other spots may not. With $100 already in paint on hand without primer and clear coat, why skimp on 2 $6 cans of filler primer and $6 worth of sand paper? My typical paint job on a 4" 6 foot tall rocket consists of one can of primer($6), one pack of 600 grit sand paper($6), 2 cans of Montana Gold($12-$15 total), and 1 can of 2K clear coat($22), and some tape.

 

[Orien]

Who said \\

It all depends on the particular run, but I've had pieces that showed the weave after many coats and reasonable sanding. Some pieces will drink it in and fill in nicely, other spots may not. With $100 already in paint on hand without primer and clear coat, why skimp on 2 $6 cans of filler primer and $6 worth of sand paper? My typical paint job on a 4" 6 foot tall rocket consists of one can of primer($6), one pack of 600 grit sand paper($6), 2 cans of Montana Gold($12-$15 total), and 1 can of 2K clear coat($22), and some tape.

Who's skimping? I just haven't decided which kind of primer to use. Was leaning towards regular, but might as well get the filler. This will be my first go at 2K clear coat as well. It's a rather ambitious paint job.

 

[tsmith1315]

If you have a compressor, get a cheap hvlp spray gun and a can of inexpensive auto primer like KBS Fusion. You may never buy primer in a rattle can again.

 

[Orien]

A neat, tight dry fit. Not a piece of carboard or wood in the box. 100% composite. I feel like I'm in a higher class of rocketry now.

 

[Banzai88]

Yep, the tight fit of parts that almost hold themselves together with the dry fit mock up is very high class!

 

[Orien]

The first thing I did was sort out exactly where the centering rings go and the order of assembly. If I do this right, I can get perfectly straight fins and still be able to pull out the fin can to do internal fillets.


Then I set about getting the fins aligned for another dry fit so I could mark their root edges on the motor mount. I did not have to number the fins as they all fit perfectly wherever I put them. Then I masked off a root edge on the motor mount and applied JB Kwik Weld. I also applied a little to the root edge on the fin itself.


Working quickly now, I slid the motor mount into the airframe and used the slots to help align it. Then I wedged the fin in tight between the centering rings. This alone was holding it pretty still. But then I slid the boattail assembly into place adding another alignment guide and support. Now it was really locked in place. Finally I slid the fin jig down. A super snug fit, too. No need for shims.


After about 15 minutes, I pulled the boattail off, then the motor mount, and I repeated the exact same process for all four fins.

 

[Orien]

The fins are perfectly straight and locked in place. Now I can access the internal structure and do fillets before installing the entire assembly.

 

[Orien]

I wanted to make the fins a permanent fixture ASAP. I masked off the fillets, sanded with 220 grit until the top layer of fibers was showing, cleaned the surfaces with acetone, then just some mix-n-pour action with good old Bob Smith 30 minute. I also checked alignment obsessively throughout the process.

 

[3stoogesrocketry]

This rocket eats L1000's. What are you thinking for a motor this time ? I would say a K990 DM to be conservative.

 

[Orien]

I didn’t get any shots because I had 15 minute epoxy starting to run everywhere and i was getting panicky. But I soaked the end of the shock cord (where the pin is), spread some on the boattail coupler, dumped some in between the forward centering rings, and slammed it all home.

A little CA to tack down the slotted airframe to the boattail coupler was all it took to get the two sections lined up perfectly. Now the external fillets will lock everything together.

 

[Orien]

Somehow installing this...


...made this much mess:

 

[Orien]

For external fillets, I would mix enough Bob Smith 30 minute to do two. I would tap the cup on the table to get air bubbles to the top so I could pop them. After masking, I'd simply pour it in leaving a good inch on either end dry. Then I'd just rock-n'-roll the rocket to get it to settle out.


Once it looked good, I'd peel the tape off after it started to set but while it was still a little runny. A little alcohol on a paper towel to sculp the ends and Voila! Nearly perfect fillets.

.

 

[Orien]

Some of the paint products showed up today, and since I have low impulse control, I wanted to paint something with it immediately to see what it looked like.


It's only one of the three colors, but the nose cone is this color so I set about putting it together. Step one is to secure the bolt that the aluminum tip screws onto.


Oh please please please come off again... YES!


This was a good spot to use the rest of the JB Kwik Weld. I also prepped all surfaces by sanding with 220 grit and cleaning with denatured alcohol. The JB locked the eye bolt and secured the bulkhead to the shoulder. Then I poured in a LOT (kind of on accident) of Bob Smith 30 minute. That oughtta hold her...


Then more 30 minute to secure the shoulder to the nosecone. I had to drill a small hole in the bulkhead to let the air out as I slid it on.

 

[Orien]

Nosecone assembly complete and an exclusive sneak-peak at the paint job!

 

[GAP]

May I ask why you chose to use Bob Smith epoxy for the fillets?

 

[Orien]

May I ask why you chose to use Bob Smith epoxy for the fillets?

The brand really wasn’t that important to me, but I like traditional 30 minute epoxy because it pours and flows well (as described above). And if the surface is prepped properly, it’s plenty strong enough.

 

[Buckeye]

The brand really wasn’t that important to me, but I like traditional 30 minute epoxy because it pours and flows well (as described above). And if the surface is prepped properly, it’s plenty strong enough.

This rocket kit doesn't get the love it deserves. It is a sweet performer with the cool tail cone. Mine has the original plastic nose cone and tail cone which have held up very well through K550 and similar motors. Mike flew the prototype on an L800-something, I believe.

I used to do my fillets the same way - pour in Bob Smith epoxy (30 min, or 3 hour) and let it self-level. However, the external fillets didn't hold up very well, and would eventually break or crack. They were heavy, too. Later on, I started mixing in fumed silica, and now I simply pull fillets with RocketPoxy.

Your equivalent internal plus external fillets may be a little overkill, but OK.

 

[GAP]

The brand really wasn’t that important to me, but I like traditional 30 minute epoxy because it pours and flows well (as described above). And if the surface is prepped properly, it’s plenty strong enough.

Yeah, just so you know when you start working in composites the composites start being just as strong or stronger than the epoxy. Here is a good example of this, http://www.jcrocket.com/adhesives.shtml

 

[Orien]

This rocket kit doesn't get the love it deserves. It is a sweet performer with the cool tail cone. Mine has the original plastic nose cone and tail cone which have held up very well through K550 and similar motors. Mike flew the prototype on an L800-something, I believe.

I used to do my fillets the same way - pour in Bob Smith epoxy (30 min, or 3 hour) and let it self-level. However, the external fillets didn't hold up very well, and would eventually break or crack. They were heavy, too. Later on, I started mixing in fumed silica, and now I simply pull fillets with RocketPoxy.

Your equivalent internal plus external fillets may be a little overkill, but OK.

When I did construction years ago, we'd come across blueprints that had us seemingly over-building things. I mentioned this to my foreman mentor sometimes and his response one day always stuck with me: "It's overkill until it isn't. This building is rated for 150mph, but what if a hurricane comes through with 155mph winds? or 160? or 170?" I also understand there are 100 different philosophies on adhesives and construction methods. Eventually, ya just gotta go with one, right?

As for the kit, I can't speak for it's performance yet, but the materials, fit, precision machining, styling... It's far and away the highest quality and most inclusive HPR kit I've ever purchased.

 

[Orien]

Yeah, just so you know when you start working in composites the composites start being just as strong or stronger than the epoxy. Here is a good example of this, http://www.jcrocket.com/adhesives.shtml

In the G-10 example for Bob Smith 30 minute, 500 lbs. breaking force required. I can live with that. Do I really need over a ton on a six pound rocket? (rhetorical).

Anyway, I've read the sticky several times and feel confident with what I've got for this particular rocket and it's planned motors.

 

[JackC]

If you are going for an L2 with an 8 to 9 pound rocket, why would you go for a K motor when a J motor would do the trick? A Cesaroni J295 or even the J210 would work well with your rocket and would allow you to easily see it through the entire flight.

 

[Orien]

If you are going for an L2 with an 8 to 9 pound rocket, why would you go for a K motor when a J motor would do the trick? A Cesaroni J295 or even the J210 would work well with your rocket and would allow you to easily see it through the entire flight.

BECAUSE MACH 7 DOESN'T "DIAL IT BACK"! ONWARD AND UPWARD! I JUST HAD MY REAL NAME LEGALLY CHANGED TO MAX POWER!! GET SOOOOOME!!!!!!!!!

Wait. See it through the whole flight, you say? Like even touchdown? I shall hear more about this.

 

[JackC]

BECAUSE MACH 7 DOESN'T "DIAL IT BACK"! ONWARD AND UPWARD! I JUST HAD MY REAL NAME LEGALLY CHANGED TO MAX POWER!! GET SOOOOOME!!!!!!!!!

Wait. See it through the whole flight, you say? Like even touchdown? I shall hear more about this.

Yep. Insert those two motors in your Openrocket simulation and see what it tells you. If it’s a nine pound rocket, it should be .5 Mach and reach 4700 to 5200 feet. Very respectable and in the line of sight throughout the entire flight. Each motor is as easy to build as the K, one is three grains, the other is two.

 

[Orien]

Yep. Insert those two motors in your Openrocket simulation and see what it tells you. If it’s a nine pound rocket, it should be .5 Mach and reach 4700 to 5200 feet. Very respectable and in the line of sight throughout the entire flight. Each motor is as easy to build as the K, one is three grains, the other is two.

I'm definitely thinking J motor for cert/maiden flight. The plan is to get a 5-grain CTI case and two spacers. I have a new found respect for the forces involved with full K motors now after this disaster.

 

[JackC]

I'm definitely thinking J motor for cert/maiden flight. The plan is to get a 5-grain CTI case and two spacers. I have a new found respect for the forces involved with full K motors now after this disaster.

That sounds like a good plan! Get a J, get certified in a way that allows you to see the rocket’s performance during the flight (does it have a wiggle during boost? Is it arcing over to one side too much? Those may indicate the need to add nose weight or a construction issue to fix). It’s hard to notice this stuff when boosting with a K motor.
If you want decent power yet keep the rocket in the ballpark, you can use the K530 Smoky Sam 4 grain motor. Fairly slow boost at .5 Mach to 6,000 feet or so. Black smoke and nice tracking smoke to help keep your rocket in sight.

 

[mrwalsh85]

BECAUSE MACH 7 DOESN'T "DIAL IT BACK"! ONWARD AND UPWARD! I JUST HAD MY REAL NAME LEGALLY CHANGED TO MAX POWER!! GET SOOOOOME!!!!!!!!!

Wait. See it through the whole flight, you say? Like even touchdown? I shall hear more about this.

Turn. Up. To. Eleven.