7.5 V-2

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blackstool102

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Starting my polecat 7.5 V-2 for my level2. Is there a site concerning this build? i am not sure about fin covering,, i.e. carbon fiber with a layer of fiberglass? I was told the fiberglass will protect the carbon from impact damage. I am an a&p mechanic, and work strickly composites so i have a good working knowledge of aramid,carbon and fiberglass. Also would like to do duel deployment .. do i wrap the tube in cloth?? lastly,, i plan to make close to scale fillets from 3M EC-3524. luckily in the aircraft world, all of our products have a shelf life,,, resin,fillers paint. any help would be appreciated
 

rharshberger

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While CF would add stiffness to the fins it would also add weight. Weight at the rear of a V2 is a bad place to be adding weight since every ounce at the rear needs another ounce at the nose to offset the degradation in stability. As was being discussed in another thread, any process which saves weight on the rear of a V2 is a good choice. As for wrapping the airframe, Polecat only sells that kit with a FG wrapped airframe iirc the only reason to do another wrap on it I can think of is to simplify the filling process as the weave they use is pretty large. Sounds like you already have a good grasp on working with composites, and the materials to be effective with them, hopefully you plan on doing a build thread for this project.
 

blackjack2564

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One of the biggest draw backs to big V-2's is the amount of nose weight usually needed, when flying large heavy motors.
Short airframes, mostly nose cone & tailcone, make for hard to dual deploy projects.

I came up with what I call the 'Doughnut Av-bay"which allows you to fly larger M-motors.....the motor goes right up into center of electronics bay! Instead of just 3 grain 75 motors, I can get full 5 grain M's onboard. Last flown on a White Thunder 5 G M to 14,480ft at mach 1.4 in a 6 in V-2.

I have 1in . sleds to which all gear is attached, being 7.5 in. airframe you should have a bit more room, depending on whether you use a 75 or 98mm motor mount.

See here for how I do this: Look at link/pictures first, then read this, it will make more sense........

https://www.rocketryforum.com/showthread.php?64674-CJ-s-WildMan-6in-V-2-build&p=1651022#post1651022


use a centering ring and another motor tube on one end of electronics bay, on front end a solid bulk plate with another centering ring inside glued to it. This "grabs" the motor tube keeping it centered.
Motor tube is glued into rear Cr/bulkplate and comes apart/out on that end, for prepping & BP charges for Dual-deploy.


This puts all the weight of electronics-batteries- etc in the nose cone coupler & the shock cord and main chute in the NC. At apogee the NC comes off and drogue out the fincan.
NC is shear-pinned to NC shoulder and blows off shearing pins at 700ft.

I actually do not need ANY nose weight. It weighs 7lbs with all the gear in there....up high where it belongs!

Ready to fly no motor my weight is 18lbs....I think.

Funny when searching for this old build thread, I found I never posted a finished pic..so I brought it back from the dead & did so...LOL

If you ARE going to do DD [dual deploy] figure that out first....will determine how you actually build!
Yes wrap the airframe in glass.
Foam core fins can save tons of weight in rear & they are plenty strong. Being in composites business I would think you may have used this process with either foam or balsa blocking sheets/honeycomb core.
 
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