the Agate...an Onyx with attitude!

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Elapid

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well, i got a LOC Onyx kit in a raffle and it finally told me what to do with it. first off, the 29mm MMT had to be scrapped... the fins were cut improperly (grain was not parallel to the leading edge :( ), so those were also scrapped. the nose cone didn't leave enough cargo area, so it was trimmed so the hollow portion could be utilized...lead fishing weights were epoxied to the inside of the nose cone first, then expanding foam filled 2/3 of the cone, then a plywood bulkhead was fitted with a U-bolt, then potted with epoxy reinforced with milled fiberglass.



the body tube was notched to accept TTW fins, then a layer of fiberglass and CF mat was used to reinforce the airframe. i used an extra long piece of fiberglass cloth so that i inded up with fiberglass on the inside as well as a couple wraps on the outside using a single piece of .75 oz cloth.



the fincan was constructed using LOC 38mm MMT tubing, the stock centering rings enlarged to accomodate the larger MMT, and new aircraft plywood fins all bonded with JB Weld. once that ws cured, a layer of the CF mat was applied tip-to-tip with a .75 oz fiberglass veil.



i'm most likely going to replace the eye-bolt with a welded one before i install the fincan.

here's the rocksim file...v7.. it's not exactly accurate as far as materials list, etc. i made it as a blueprint and testbed and will modify the file to reflect reality when the rocket is fully assembled and painted.
 

Elapid

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well, the whole thing is my first time doing CF/fiberglass as if it's not obvious... :)

i tried something different to keep things snug, since the cf mat doesn't like to stay rolled around the tube. i used saran wrap to seal it up, then wrapped the whole thing with 2" wide masking tape to simulate the heat tape method.

the saran wrap was a bad idea.
it is so thi, i can' tbe sure the shiny surface was stuck saran or shiny resin... :(
the whole thing needs to be roughened up with a scouring pad to be certain all the poly film is gone.

mylar would have been a wiser choice.

next time.
:)

mailing tube end caps fit the ends of the tube perfectly to keep the resin from getting in. i only had one, so on the other end, i used aluminum tape around the inside of the body tube to keep from getting the inside of the tube all messy. it worked out well.
 

Stymye

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heavy duty ! I always liked the onyx, nice and stubby
 

DPatell

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Hmm, CF Mat...interesting. I thought it was usually used on flat surfaces to prevent flexion in any and all directions? Such as on my Alien Enterprises Monocopter24. The balsa wing was laminated with the CF Tissue in order to prevent it from flexing due to the aerodynamic forces.

I always figured the normal woven cloth was better, as it has a definitive axial and radial strength benefit, without the fibers running diagonally, which are unneeded.
 

Ryan S.

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Originally posted by Elapid
well, i got a LOC Onyx kit in a raffle and it finally told me what to do with it. first off, the 29mm MMT had to be scrapped... the fins were cut improperly (grain was not parallel to the leading edge :( )
"P-L-Y-W-O-O-D.... Ever heard of it?"
 

Elapid

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nice of you to drop in and comment!
:)

it is my feeling that having strength on all axes might be beneficial in side-loading situations, as in landing stresses... regardless, it's what i have on hand (CF mat) and i am fairly certain it will be strong enough to handle the loads that i intend to subject it to.

give me any 5 builders and one project, and i'll bet there are at least 7 opinions on how to build it *properly*

such is life.
 

Elapid

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Originally posted by Ryan S.
"P-L-Y-W-O-O-D.... Ever heard of it?"
i knew you'd show up...
hahaha!

plywood has grain direction...maybe you haven't noticed, but your plywood bends easier in oe direction than the other direction oriented 90* to the first.

try it.
anyway...
thanks for your comments, whatever they mean.
 

rabidsheeep

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chat called upon this cheer:

lets go moderators *clap clap, clap clap*
 

rabidsheeep

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if your gonna try and get banned could you atleast be original and not just copy the urls of premade ebaums sites? i mean lets get creative here people, comon...
 

Stymye

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Elapid has a point ,if it's 3 ply than there is a definate strength difference...I hate the way vendors toss the "aircraft ply" name on anything.I try to find atleast 5 ply for my money.. craft store
3 ply is fine for birdhouses.
 

Ryan S.

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just a tip elapid, I like your tape idea, but what works the best is plastic packing tape. it comes off no problem, I use it to glass all the time.

HTH
 

Elapid

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i'll have to give that a go next time.
thanks.

this sig plywood definitely bends easier along one direction than the other. it is related to the grain direction in the skin sheets. i always make fins with the grain parallel to the leading edge. with this, the plywood seems redundant...the CF alone would suffice.
the stock fins were surface mount, so they would not be suitable for this application, anyway...
i'm fairly certain the fins aren't coming off this one.
it should be stable.

i don't see a problem.
except that it's ugly.
:p

nothing that can't be smoothed over with a little primer and paint. I'm planning on using a base of gloss black with SpazStix Holographic color-changing paint.


wait til they see my 54mm minimum diameter project based on the lil Nuke
;)
 

Karl

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Isn't that the paint that changes colour due to temperature? Very nice! :cool:
Karl
 

Elapid

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this shot shows all th edifferent colors...

gold, orange, green, purple
:D
 

Elapid

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Originally posted by Karl
Isn't that the paint that changes colour due to temperature? Very nice! :cool:
Karl
hey karl!
thanks all!

the paint from https://www.spazstix.com changes according to the angle of the light reflecting off the surface, from gold when the light is behind the rocket, and purple when the model is lit from the front side.
 

Elapid

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It came in a bit heavier than i had hoped, 1100g, but still reasonable...
i'm using my Skyangle Classic 32" for recovery with 5.5mm Spectra accessory cord shock line.

i'm tempted to pick up one of those aeropack boattail retainers to finish this off in style. with the boattail, it sims a little higher/faster, too.

i like the look with a boattail also...
i guess it will depend on the cash flow situation.
:D

thanks again for the replies!
 

DumasBro2

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I like that paint. Holy cow! 1100g????? what are you gonna fly that thing with?

steve
 

Daedalus

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Originally posted by Elapid
It came in a bit heavier than i had hoped, 1100g, but still reasonable...
1100g - that's about 2 1/2 times heavier than stock - that sounds seriously overbuilt for pretty much any 38mm motor. Would be 'interesting' on a US Rockets J1200 - but that is too long a casing I think... What motor are you intending to fly it on?

i'm using my Skyangle Classic 32" for recovery with 5.5mm Spectra accessory cord shock line.
Again sounds like a bigger Skyangle chute than is required - especially with all that reinforcement - you may as well bring it down hard and fast.

Look forward to seeing the launch photos.
 

Elapid

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the stock Onyx was designed to handle 29mm G-impulse motors, this was designed to fly over 800 mph on the 38mm J350W and the other loads for the 38/720 casing and to do it without a whimper. over and over again.

the skyangle classic 32 is one i bought for another rocket. since it fits so nice, and since i will be flying it at black rock with 400 square miles of treeless recovery area, i'll bring it down slowly.
 

Daedalus

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Originally posted by Elapid
the stock Onyx was designed to handle 29mm G-impulse motors, this was designed to fly over 800 mph on the 38mm J350W and the other loads for the 38/720 casing and to do it without a whimper. over and over again.
I'm sure it will do that fine. The recommended motors for a lot of LOC kits are a little less than I like to see in them.

the skyangle classic 32 is one i bought for another rocket. since it fits so nice, and since i will be flying it at black rock with 400 square miles of treeless recovery area, i'll bring it down slowly.
Given where it is flying the classic 32" is a good choice. I have one too and it is a very high quality piece of kit - just a pig to pack in a 2" tube, the fit in the Agate will be much easier.

Happy flying.
 

DumasBro2

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Hmmm…how much nose weight did you add? The stock Onyx is marginally stable to start with. The longer motors will help somewhat. Are you wrapping the parachute around the motor? Seems to me space will be at a premium just like a monotube hybrid.

steve
 

Elapid

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i put in 4 oz of lead, followed by 6lb density foan, and then a bit of epoxy resin to retain the u-bolt/bulkhead.

space is at a premium, but since i modified the nosecone, there is an extra 3 or 4" of *extra* space.
:D

the CG of the model is 14.2" from the tip of the nose
overall weight is 1100g

with the motor loaded up, there is slightly over one caliber of stability (Rsim).
 

Elapid

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i finally got to fly it!
it went up at HardRock 2005 (Mudrock 2005 was canelled for some crazy reason :confused: )

first flight was on an I366 Redline, and was absolutely straight up and a bit on the rapid side (6900' and Mach 1.02:D ).

there may be video of it..
 
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