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rfjustin

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This 5.5” Nike Smoke started life as a direct from Curtis including the proper Nike Smoke nose cone around 2012 or 2013. The cone was the gel coat fiberglass cloth version, not pure filament wound. To make a long story short (rockdoc can add details if need be), the gel coat nose cone met its demise when it fell off of a storage rack and hit concrete. For many years, a new nose cone was not an option, and I eventually took over the project from rockdoc (sans Nike nose cone of course). I was not dissuaded by the lack of availability of the gel coat Nike Smoke shape nose cone, and ended up picking up a pure filament wound conical cone from Mad Cow plus a new, longer coupler to accommodate head end dual deploy. While I was on the Mad Cod site, I did notice the 5.5” Nike Smoke seems to be coming back: https://www.madcowrocketry.com/5-5-inch-nike-smoke/

Rockdoc had installed the 75mm motor mount, installed the fins, foamed the fin can, and applied nice external fillets as well. The rear centering ring was not yet installed, no rail guide holes, vent holes, or shear pin holes were drilled yet when I took over the project. Instead of using conventional dual deploy between the 33 inch booster and 12 inch upper airframe, I decided to go back and couple these sections back together via 6-32 PEM nuts. I also added a single 4-40 PEM nut which serves as the backing for the Additive Aerospace Mobius camera shroud. I wanted build this Nike with modularity in might just in case a single piece got damaged. I mounted (2) 8-32 PEM and (2) 10-24 PEM nuts for rail guides before the rear centering was adhered. I adhered the rear centering ring and some lightly amended west systems in the back, then drilled and tapped the holes for a flange mount Aeropack 75. For all intents and purposes, the booster is done. I might skip ahead to some filling, priming, and painting the booster as time will allow between working on the avionics bay/nose cone.

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The nose cone/avionics bay consists of the long conical cone, 2” switch band, and a 12” coupler holding everything together. Instead of capping off the ends of the avionics bay coupler, I’m going to recess a separate 6” long piece of coupler that has been split lengthwise. The avionics bay coupler plates at each end of the coupler will rest on this separate coupler that was split lengthwise. This will help gain space on the top for parachute/cordage and also gain motor case space in the booster. The switch band has been glued in place, but this separate inner coupler will be bolted in place, and not made permanent in the spirit of modularity/serviceability. The top of the inner coupler will be bolted with (8) 6-32 socket head cap screws that will go through the switch band, into the 12” coupler, through the 6” split coupler. This should sufficiently hold everything together and prevent any shifting during flight and deployments.

Next steps are to drill switch band vent holes, line up a Missile Works 3D printed avionics sled, drill holes to access the Schurter 110/220 switches, then install the inner coupler. More details and pics to come as time allows…

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Subscribed. I like your idea with the smaller split coupler, quite unique! I had to read through your post twice to figure out what you were doing. I'm also a fan of liberal use of pem nuts, but I always seat and fillet the inside edges with epoxy. Had a couple come loose in two of my earlier builds, smaller diameter, real pain to remove and repair.
 
I like your idea with the smaller split coupler, quite unique!

Thank you sir. I'd did realize after the fact a shortcoming of the design though... When I drop the prepped bay in from the top (nose cone side), aligning the threaded rods through the lower plates will be a PITA as both sides are recessed. Might need to chew on this a bit more... :)
 
Here is the 6” long coupler that was split and the efforts to make sure everything will line up.

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Enjoying this one, Justin! Looking forward to seeing it out on the range!:)
 
Got a little work done on the drogue and main recovery cordage. Need to cut some threaded rod and finish up the avionics bay.

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Justin, it looks like you might have done this before😀 Seriously, looking good as always.

Now it needs a hipped booster...
 
I decided to add a parachute "shelf" yielding two advantages. 1, keeps the parachute burrito a couple inches away from the charges. 2, it helps keep the threaded rods straight and true for easy avionics removal. :)

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Nice build Justin. I did something similar on my 3" Saab build. I epoxied the upper bulkhead into the coupler 2" from the end. It leaves a little more room to pack the main into.
 
Last of the actual build completed. Got the nose cone anchor installed. I needed to drop the connection point down in the cone to allow for arms length installation and removal of quick link. Next week will bring ground testing and possibly beginning of filler, primer, repeat.

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Prepped for ground testing...

- 3.0 gram drogue charge using (2) 2-56 shear pins
- 2.5 gram main charge using (4) 4-40 shear pins

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Ground testing complete... primary charges tested were spot on IMO...

[video=youtube;GuOSOiknZUo]https://www.youtube.com/watch?v=GuOSOiknZUo[/video]
 
Deployment looks perfect, sir! Really enjoying this thread by the way! :cheers:
 
I thought both deployments looked a little strong. Especially the drogue. You only need enough to get the drogue chute into the air stream and the drag of the drogue chute will stretch out the shock cords as things stabilize. In the air, those two halves will probably hit the ends of the cords pretty hard since the ground won't be there to stop their momentum.

just my opinion. Watch the deployments in the air and you decide.

Good luck
 
Is that a wig you put on the nose cone when you tested the main charge???


:confused:
 
I thought both deployments looked a little strong. Especially the drogue.

I agree the charges are on the spicier side, but ballistic recoveries scare the crap out of me.

We shall see what the on-board shows when it flies. K-1275 for a maiden flight sooner rather than later.
 
Justin, where did you fly?

Princeton, IL. It was a last minute idea we cooked up. I think we flew 5-6 flights, then packed up the one pad and one rail we used in the AM.

3744' feet, perfect flight. Jason took a video of the up part, thank you sir!

[video=youtube;TYdo8PFZvSM]https://www.youtube.com/watch?v=TYdo8PFZvSM[/video]
 
Justin, I like your reaction. The K1275 is an ass kicking motor. Sounds like a fun outing.
 
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