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bandman444

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That's it! I'm addicted!

I had to make a new folder in rocksim just because there were so many files!

The smallest being a 1/2" Diameter scale model with fins made from a hotel key from my vacation recently. Flies great on 1/2A's!

Next (my fav) a bt-80 adaptation that stands 16inches tall. Flies AMAZING on C6-3/5's. (Ate all 15 I had that day!) Also liked the last few B4-2's I had. Highly recommend as an easy scratch build!

Next up...

I was in toy-r-us and my dad yells to me that he found the rocketry section. I was so excited, I ran to him and....it was a row of crayon banks. My dad thought he was kidding...hahaha, I made him buy me one. It's not yet built, but will be soon. it is 3 feet tall and has a 38mm mount ready for G's and small H's.


High power guys. You ready?

My level 3 will be a squat, but a 20" diameter squat. I asked about how to make a nosecone for an irregular sized tube here on TRF a couple months ago and settled on an unorthodox method. I had known it worked on small diameter body tubes and wanted to see if it would work out.

I already bought the tubes for my Level 3 about 2 weeks ago (very nice Sonotube) and this morning went by Home Depot to get my "test" tubes. Half scale 10" nominal diameter Quikcrete tubes. I had to make sure I got 2 identical diameters (which I did).

So todays test went well, the biggest issue was cutting the tube smooth. I think my new dremel will take care of that though.


So the 10" will be a 2.5x upscale from the original and will have a central 75mm Motor mount and 1/2" 5ply fins.


The 20" will be a 5x Upscale and stand a massive 12ft tall. And will have a central 150mm mount surrounded by 4 54mm (75?).


Pictures!

The little ones

Crayon Rocksim Squat

Todays test

Tomorrows test


Thanks guy,

Bryce

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Crayon Squat.jpg

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You've... You've created a monster! Is your level 3 going to be on an O?
 
Ok here you go you guys.

For all those naysayers that didn't think it would work, here you go.

The nose cone was made from one 6 foot piece of 20"diameter Sonotube.

I measured the circumference of the tube then divided it by ten. (My cone had 10 triangles) Then, starting at the bottom of the tube measured 1/2diameter (10") up and drew a line all the way around. This would be where I would stop cutting.

On the line I made 10 marks around then you need to mark a vertical line from one of those 10 points.

I grabbed 6ft of thread and a washer and tied the washer to the end of the thread. Then I taped the top of the thread to one of my marks (The tube is upside down now). I stacked the tube up on 3 soda cans so that the washer would hang down passed the bottom of the tube. I then made the tube level on all three axis using shims under the cans, ad then finally marked where the thread hung. Tahdah. A plumb!

Then I used that mark and measured 1/20th (half of the tenth) around the tube. then from that point started with my ten measurements. (So that they are all staggered.)

Lastly I used painters tape to mark a line from each opposite point to the other.

I used a Laser guided jig saw to cut it out. First starting it laying down till I had cut 4 "spikes" out (then it wouldn't sit right). Then I had to stand it up to cut the rest out. Uncomfortable for sure.

The next step will be to wrap it in Monokote (maybe something else) (I have some for my model airplanes) and then fill parts of it with 2-part expanding foam. I want to get it around the edges to fill in the slits in the nose cone. But I want to leave it as hollow as I can so that I can add the appropriate nose weight farther into the build.


Well I got to wait till school starts to start working on centering rings and fins.

Enjoy.

Bryce

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laser cutter for CRs and fins?

looking good, can't wait to see how it progresses :)
 
I see you liked my name!

Naw I think if it is going to have to handle an "O" it need to be 1/2 or 3/4" our laser won't cut that. (Plus the table is only 12x16" :p )

But I plan on monkey-ing around to see if I could fix our CNC router.


Bryce
 
The 10" has a chance of seeing the sky in ROCtober, The HUGE one (possibly named " "O" Squat") Can't fly till April at the earliest. (I have to be 18 to get L2 and L3 Certified)

I may bring the monster in October though. (If it fits with Size Matters and the Mega Mean Machine)

Bryce
 
just put size matters or the MMM inside the body tube :D

Also, if you're gonna use the megaskwat to cert you'd have to get tripoli, NAR requires L2 before you can start any planning for L3.:confused2:
 
How are you coming along on the Mega? I'm embarking on a similar project and am curious as to how you finished off the nose cone.
 
So far the Mega is looking really good. I haven't been keeping an accurate build log here on TRF for political reasons, BUT you asked. :)

The body tube has been wrapped in two layers of IIRC 6oz glass. I used an entire quart of hardener on it and it turned out relatively ok. My theme for this project is that it need to look good from "500ft". Up close it will look like a disgusting monster but hopefully from the launch pad it will look like a decent rocket.

That being said every picture on here will be within the 500ft line so thing will probably not look as clean as they are.


Ahhhhh the nosecone:

Well as I believe I discussed earlier I cut the nosecone into a large crown. (And for those of you just tuning in it is a 20" diameter 6ft tall crown)


IMG_0007.JPG


Next I started with the tip of the cone so that when I fill it with expanding foam it would basically turn into a giant cup.

So i got the tip just the way I wanted it using a tennis ball, some rubber bands, and a couple centering rings.

IMG_0124.JPG


Next I needed to put in the 7.5" 5ft "stuffertube" so that the foam didn't have to fill THE WHOLE cone. So to Align everything I used hot glue (because it was fast, free, and forgiving) and some barbecue skewers.

These were measured and cut to exact lengths so that they are all tight and correct.

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Note: the green string is there to suspend the nosecone upside down from my ceiling.

Once everything was glued in the final position then I wrapped the whole nosecone in plastic wrap.

YES 200ft of plastic wrap.

All in an effort to contain the foam "in the mold" kinda.

All the holes were patched and I thought we were ready to FOAM-INATE!

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Before

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After
(Note: Yes the cone looked like it caved in on that right side and that is because there were no sticks holding it. next time I will add a few more rows of sticks and wrap the plastic wrap a little easier)



So I mixed my first batch of Giant Leap Rocketry's "MEGA-Foam".

This was my first time working with any kind of expanding foam and I did not get what I was expecting. I thought that it would literally expand instantly as I mixed and that I would have under 10 seconds to to rapidly mix and pour the stuff. HAHA I was wrong!

I made my batch using two dixie cups and a plastic pretzel jar, I filled both cups to one of the lines and then dumped them both into the large pretzel container. I mixed furiously waiting for the reaction to happen, and what I thought would happen did, but in extremely slow motion. So I poured in the foam and watched it rise...a little. I was thinking it would expand quite a bit more. I actually mixed the rest of the foam in about two or three different batches and was extremely UNIMPRESSED with its "expanding". I used all of the $40 worth of foam and filled only the first 15" of the 72" cone.

IMG_0139.JPG


All poured in, but without bloating.

I kinda thought it would have filling up the whole nosecone...

So after letting it cure I peeled off the plastic wrap where the foam actually got.

IMG_0156.JPG


And after 2-3minutes with a razor blade.

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Pretty darn nice if you ask me!

And that's it for the nosecone. I emailed giant leap Yesterday. The foam only expanded about 7-8times rather than the 20-30 their website states. I really hope that they offer to send me another thing of foam because what I got was really good, it just seemed to have some sort of defect.



I have gotten a lot of other stuff done.

I slotted the body tube (Ok I did one slot!, but it took over an hour)

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Motor Mount:

Ok now the meat and potatoes of this rocket.

She holds a central 150mm mount and 3 outboard 98's. The three rings were precision cut by Jared Shapiro (edwinshap) on a computerized CNC machine at his college. Two of the rings have all 4 holes and the last one only has the main 150mm)

The motor mount uses a custom 150mm fiberglass tube that I believe (if I heard the story right) was leftover from the Mega Darkstar build) It is 38" long and cost more than the rest of the project combined. ($260) Ouch...

The other mounts will probably be Blue Tube, but I haven't picked those up yet.

Pictures! (nothing has been glued yet)

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Ok. Here's the deal.

I live in California. Everyday this thing gets heavier and heavier. Right now as is. The cone weighs 30pounds, body tube weighs 22, motor mount (centering rings and tubes) weighs 20, fins weigh 6lbs EACH (18pounds total). So without filling the rest of the cone, and without parachutes, harnesses, electronics, she weighs 90pounds DRY. I don't think it is to far fetched to say she will weigh 150 dry. 180loaded.

In California we are restricted to an "M" impulse limit. Realistically she can do barely 2,000ft on the 98%M M3400WT. That to me would be a scary flight. She needs an "N" or "O" to fly Safely.

Now of course it is not entirely my decision, but my L3 correspondents need to be onboard with the flight trajectory no matter what it is.

As far as I know at LDRS 2 years ago the "M" impulse limit was alleviated because the State fire marshall came out and granted special permission. I really don't know what was involved there but if you or someone you know was involved with that please Pm me so that I at least know what it takes to launch an "N" in California Legally.

If not and she does indeed weigh enough for it to be unsafe on an "M" then I will be happy to make the trek out to Nevada or Kansas to see this thing fly.


If you want to see the rest of the photos and stuff then check out the link below. https://picasaweb.google.com/101067158742142074137/Level3BuildPictures?authuser=0&feat=directlink




Thank you guys for reading.

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Bryce
 
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Thanks for the insight Bryce, very similar to what I'd come up with. Mine's only 8" diameter, so I think it will be quite a bit easier. I was going to use the foam from U.S. Composites, 4# looks like it should do the trick. Do you still have those 38/120's available? If so, I'll take them.
 
A little, no major work.

I have glued the two forward centering rings to the motor mount, but thats about it.

I'm in the middle of my high school rocketry teams Mach 3 project, and most of my time and energy right now is devoted to making that a success.

The nosecone issue is whats really got me in the hole. Essentially that leaves me $300 or so dollars that I didn't budget into this project, and although that may not seem like a lot when you factor in a $500-800-2000 motor, it is an added expense that I was not planning. (Not to mention the huge hole I dug when I ordered for the Wildman Black Saturday Sale)

If the nosecone had gone according to plan, I think this rocket would be nearly ready to go, but I am unmotivated to do other things like securing the motor mount and getting the fins on, since I have main portion of the rocket not taken care of.

If it is any measure of where I stand High Power wise, I do own two L3 capable birds and may choose to TRA cert on a rocket that has flown comfortably before. Not to mention that my schools project will be L3 class motors and my APCP and adrenaline fix fed from there.


I haven't forgotten about it, but an unforeseen roadblock has gotten in the way of completing this rocket at this time.
 
Looks like you will have to add 20 lbs or so of nose weight also, so factor that into the total mass. At 200 lbs, you should probably just take her to Nevada and get it done on an N.
 
Hey everyone.

I sent an email to GLR right after the foam incident and received no response back. A couple days ago I sent the same email again, and I actually got a response. I copied this post to Kent who kindly asked that I add his input to here so that others could learn from my mistake.

The main question I have is how much product did you mix at a time? At most, I only like to mix four ounces of part A to four ounces of part B at a time because it seems if too much is combined at once, as it expands, it seems to crush in on top of itself, reducing the expansion and creating denser and heavier cured foam. Please advise.

The next thing I like to do is to let the mixed (but still liquid foam) come in contact with as many surfaces as possible. For instance, in your situation, turning the cone sideways up to the point of letting liquid run out and rotating it will coat the sides and allow the foam to expand easily with the least amount of compaction.

He also said
As for as buying foam, it's all the same from where-ever you get it.

Which is an opinion I found interesting...

I am debating whether or not purchase from them again, or find my business elsewhere. Running the numbers puts me in the need of 4 cubic feet of foam, which I may take up chadrog's suggestion and get some from US composites (since its all the same).

Thanks for staying tuned.
 
Thanks for posting that Bryce, your timing could not have been better. I put my order in at US Composites yesterday, should see it in a couple days. I'm pretty sure this information just saved me many questions.
 
Basically, the megafoam will work best if you dribble it down the sides of the nose. If you pour a cup of the stuff into the bottom, the weight of the foam on top will crush the foam at the bottom, but if you pour it down the sides, it sticks to the walls and expands outwards from there. Another thing is once it starts to generate foam, stop mixing: you can destroy the bubble structure and it merely outgasses fumes instead of filling itself with bubbles.

Patience is key: it's probably best to do the job in many, many small batches to avoid mass asymmetry.
 
Since you're in sunny California, it might not be an issue, but in places where it gets cold, I've found that it doesn't expand as well when its really cold. I'm speaking of the US Composites stuff specifically, but I also believe that most formulations would have a similar issue. I have successfully used it in the winter by bringing it in the house the day before and then taking it out to the garage when its time to mix (i.e. 70 deg instead of 40. . . ).

Good luck with the rest of the build.

Sandy.
 
A little progress.

Very little progress...

I did some work on the motor mount.

Three rings make up the motor mount. Two that have all four motors, one that has only the central 150mm mount.


The original plan was just to do some epoxy fillets to keep the motor mount in place, but I have been heavily recommended to fiberglass the rings to the mount, so that is what I did.

Not much, but basically all I did was cut 3inch wide strips of fiberglass and laminate them in the gap of the ring and tube.
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Lastly a couple pictures to put the motor mount in perspective. It's pretty big!



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