MadCow DX3 8" Level 3 Build. "OverKill"

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Mustang67

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Project: MadCow Rocketry DX3 8” Level 3 build.

This rocket is a beast and going to be an enjoyable build. My plans are to build it to my liking so with a few modifications and most likely some overkill will be involved:). Not a fan of second guessing or having to do so something twice. Again, it’s just how I do things, I prefer to build to last.

That being said, I am going to name my rocket “OverKill”. Perhaps I will air brush some cool graphics on it, like something off of one of the old Iron Maiden or Judas Priest albums.

My plans are to attempt my L3 Flight at LDRS 36 in April.

A few mods will include laying the fins in Carbon Fiber cloth. Will also use make a carbon fiber sandwich out of the forward motor mount. I will be attaching two U-bolts here for the Y harness.Will also use a thrust plate from SCS

Dual deployment: Stratologger & Raven altimeters
Motor 98mm M1600R (Will confirm after I spec it out in Rock Sim)
Recovery: Fruity Ultra Iris Chute.

Rocket Specs:

ALL FIBERGLASS KIT
Filament Wound Nose Cone
Metal Tip Nose Cone
Pre-Slotted Fiberglass Airframe
G10 Beveled Fins and Centering Rings
Dual Deploy w/18" Long A-Bay

Dimensions:
Length: 132"
Diameter: 8.0"
Weight: 48 lbs.
Motor Mount: 98mm
Fins: 3 each 3/16" G10

Some helpful links I have found on the forum and also some builds of inspiration:
https://www.rocketryforum.com/showthr...-L3-Cert-Build
https://www.rocketryforum.com/showthr...alvage+l3+jart
https://www.dashware.net/dashware-download/
https://www.rocketryforum.com/showthr...r-rharshberger
https://miles2go.com/rocketweb/Miles Anderson Blue Moon Cert. Doc.pdf

More info to follow over the next few weeks
 

blackbrandt

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Why are you planning on putting CF on the fins?
 

Handeman

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Sounds like a really cool build and a flight I'll be looking forward to at LDRS.

I'm just wondering about the weight. I have a Performer 150 that is about 138" tall, 6" diameter, 98mm MMT, and it turned out to weigh 55 lbs on the pad with a 76/6000 Loki M1882 motor. At near the same height but 8" diameter, is the 48 lbs w/o motor? About +60 lbs on the pad? I would suggest you look at sims with 98mm motors being about 75 lbs. But that will work itself out as you finish the build.

Good Luck!
 

Mustang67

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Agreed, its 48 LBS dry and I believe 75 on the pad is a fair estimate. Will be sure to sim it out and look at motor options over the next few days.
 

Nick@JET

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Going to be Massive Overkill! Love the rocket and will be watching the build. Enjoy!
 

rfjustin

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How many centering rings are included in the kit? I'm trying to figure out what the advantage is of notching the root length of the fin. If I had my preference, I would rather the root be full length and use 1 or two less centering rings.

Looking forward to the build!
 

hawlk2004

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think in the pic I see 3 rings and 1 bulk plait I maybe wrong though
 

Mustang67

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How many centering rings are included in the kit? I'm trying to figure out what the advantage is of notching the root length of the fin. If I had my preference, I would rather the root be full length and use 1 or two less centering rings.

Looking forward to the build!
Comes with 3, however I ordered two x 1/2 inch rings (wood) from another vendor. I will be taking two of the fiberglass rings and laying them in carbon fiber cloth so I have the clearance and strength for the U-bolts and the Kevlar Y harness from OneBadHawk. Layer of cloth, ring, cloth, ring and cloth. For this process I like to use 30 minute Zap Z-Poxy, the set time is accurate.
 

ColumbiaNX01

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Thats cool. My 2 Cents... If built correctly thrust plate not needed (looks cool but not needed). Dont need a Y harness (just use forward motor closure threads with forged eye bolt. Plenty strong). Fins are 3/16 no need for CF. Just epoxy fins in and do fillets for each fin (6 per fin). Foam the whole fin can. Using the correct epoxy is key.

I built a full scale Amraam is this method. No y harness just 1 inch tubular nylon attached to forged eye bolt. No thrust plate, no tip to tip. The 3/16 fins were left alone. Flew in O3400 no issues with structure. Rocket was over 100 pounds. It used 3/16 G10 CR. Doing all those things you said is rewarding but adds no advantage, just extra weight. Use a better type of epoxy. I love using US Composites epoxy and Aeropoxy for laminating or structure. Rocketpoxy or Proline 4500 is great for fillets. If this is an "over kill" build then use top tier epoxies. In my opinion "Zap Z-Poxy" is just another epoxy like Bob Smiths. If you want to go over kill use something different.
 
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Mustang67

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Thats cool. My 2 Cents... If built correctly thrust plate not needed (looks cool but not needed). Dont need a Y harness (just use forward motor closure threads with forged eye bolt. Plenty strong). Fins are 3/16 no need for CF. Just epoxy fins in and do fillets for each fin (6 per fin). Foam the whole fin can. Using the correct epoxy is key.

I built a full scale Amraam is this method. No y harness just 1 inch tubular nylon attached to forged eye bolt. No thrust plate, no tip to tip. The 3/16 fins were left alone. Flew in O3400 no issues with structure. Rocket was over 100 pounds. It used 3/16 G10 CR. Doing all those things you said is rewarding but adds no advantage, just extra weight. Use a better type of epoxy. I love using US Composites epoxy and Aeropoxy for laminating or structure. Rocketpoxy or Proline 4500 is great for fillets. If this is an "over kill" build then use top tier epoxies. In my opinion "Zap Z-Poxy" is just another epoxy like Bob Smiths. If you want to go over kill use something different.
I agree 100%, the steps I am taking and some of the add-ons are not necessary. I simply enjoy doing it and like the look of the finished product, most of the time...Sometimes I do it just to add some additional time to the project:) I have an old 67 Mustang, turned it into a resto mod. A-lot of unnecessary steps, and mods were done to the car. By doing so we added 6 months to the project. The end result, its a one of a kind car, a beast and have not run into an old car buff that has not liked it yet.

In regard to the epoxy, I will use the Zap Zpoxy for the cabon fiber on the fins and forward motor mount ring. Otherwise you will not be able to see the Carbon Fiber pattern and color. Around the mounts, fins (6 per) ect. I will use Jb Weld.
 
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