Minimum Diameter 3" design/build

[Conway Stevens]

To get the fin can to mount up to the booster tube the booster Tube had to have slots cut. It wss either that or shave the fin tips on the underside so the tube would slide down i went with slot the tube slightly.

Also glued the booster zippereless coupler in place or booster/motor retention. As well as attachment point for the harness. The upper bulk plate is aluminum. Will secure a 3/8 threaded rod to the upper closure of the motor.

Pictures to come of more parts and work.

 

[Zeke Johnson]

Ive used them for probably the last 20 plus years. I get the low profile ones. They tend to install flush. Or with a little filing... use them to screw rail buttons in, mount Av bays and parts. Or to keep whatever im looking to together. Strong, light, reusable.

Could you provide a part number, or a link to the specific Avdel rivet nuts that you use? I found their Web Site, but there are quite a few variations to choose from.

Thank you,
Zeke

 

[Tractionengines]

Attached is a PDF and a screen shot from McMasterCarr for the ones we use at work, and I will be using going forward. The DKS has splines give more torque ability, and the small flange is almost non existent if you deburr the mounting hole. BUT they roll a bead on the back and project more. The "low profile" type have a inner part that pulls into the sleeve expaning it. The are lower profile, but not quite as much torque ability. (That is not a big deal for where we will use them.) I cant find a data sheet but the screen shot will let you see it. (These low profile ones match what are in his photos.)

 

[Conway Stevens]

Could you provide a part number, or a link to the specific Avdel rivet nuts that you use? I found their Web Site, but there are quite a few variations to choose from.

Thank you,
Zeke

Zeke The ones i use are for thin sheet applications or considerd counter sunk head. They are the low profile SAE thread type like the ones that Tractionengines posted on. I get mine locally at a specialized fastener store.

 

[Conway Stevens]

Finished 3 other projects, Mach1 Alien Interceptor 3 inch, 4 inch Hawk mountain Gryphon and the 8 inch Concept 200 for the Northern Colorado Rocketry Mile High Mayhem event. All flown successfully. Have a build thread on the 8 inch Concept 200 here in High power.

So now back to this project. It by all means is a higher altitude project but not a record setter. Our max window at my home field is 35k agl. My initial goals for this is reliably flying over 20k on 75/76 mm M range motors that arent crazy expensive. But just have fun flying some decent Newton seconds, enjoying tracking and recovery in a repetitive ability from 20k plus.

Continuing the build

 

[Conway Stevens]

For this particular flight im going to fly the 6000ns loki case with the M1650 cocktail. Its a 4.5 srvond burn time. With 6535 ns. Ive trimmed down some if the length and weight. Shouls be a fun 20k plus flight.

 

[Tractionengines]

Good luck. Sounds like a fun flight.

 

[Conway Stevens]

Continue progress as i decided to shorten the booster body piece 4 inches. Redcing the height and weight slightly. This motor case is shorter then the other case i will fly at a later date. Have plenty of other body tubes to use. May even try a different material like Mac performance rocketry canvas phenolic tube.

 

[Conway Stevens]

Got my Additive Aerospace fly away rail guides today. Will be flying off a 10ft 1515 rail.

 

[Conway Stevens]

Started working on the Aluminum stepped bulkplate for the zippereless coupler. This will use only threaded rod 3/8-18 stainless steel section to the forward closure that has been drilled ,tapped and set screw to keep the thread from turning along with a fkat washer , lock washer and locking nut to keep it tight on the forward closure. The thread goes up to the zippereless coupler for the bulkead to be fastened to it to retain it all in place. Im using dual 3/8 tubular kevlar that ive folded looped, slip knoted on each side of the bulkplate after making sure the 1/4 inch holes were tapered, smooth and deburred from any edges that could damage or cut the kevlar. These are the attachment points for the harness to the fincan/booster section for apogee deployment. It is then fastened to the harness with man rated 2500lb soft links .

 

[Conway Stevens]

Here is that bulkplate with its harness attachment and a spare softlink. Ive actually tested these softlinks on the recovery of a 88lb rocket successfully. Love these things. Easy to use, wicked strong. Stronger than a stainless steel quick link or eye bolt. Light weight, reusable, strength can be increased with more wraps, longer or larger material. Nothing to short a ematch connection on. Nothing metal banging around. Much harder to fail.

 

[Conway Stevens]

Here is the bulkhead assembly installed onto the zippereless coupler and fastened to the motor via 3/8 all thread.

 

[Conway Stevens]

Got everything squared up, tapered on the inside slightly, drilled and tapped #4 sheer pin holes upper and lower. I also cut small notches for alignment of the components later for ease. I used the Baddass rocketry alignment guide to mark my holes. All my sheer pins and other fasteners line up with each fin below.

 

[Conway Stevens]

I also pre measured areas of the upper air frame for where i want things to fit. Yes...this is a conventional dual deployment and in the future will be looking at other methods, hed or, drougeless with cable cutter, etc for reduced size and weight benifits. But for the purposes of this project. 20 to 30k will be its realm of performance as a redundant dual deployment flyer for M powered boost for fun not record breaking.

 

[Conway Stevens]

Getting the Av bay started and layed out.

 

[Conway Stevens]

Got the anchors sealed up with silicone. Going to connect the charges directly to the altimeters through a well nut that seals it.

 

[Conway Stevens]

Some further progress made. I actually swapped out the fiberglass bulkheads for aluminum the holes for the recovery anchor are tapered and smoothed. The nutserts are installed for the charges. 1/4 stainless steel all thread.

 

[Conway Stevens]

Was able to pack my main chute, a 84" Spherachutes ultra light chute to quite a small package. I have both the standard and the ultralight. Its more than half the weight, same strength, same decent rating and packs way smaller. This is wrapped in Amrid/kevlar fabric to see how small i could get it.

 

[watheyak]

Was able to pack my main chute, a 84" Spherachutes ultra light chute to quite a small package. I have both the standard and the ultralight. Its more than half the weight, same strength, same decent rating and packs way smaller. This is wrapped in Amrid/kevlar fabric to see how small i could get it.

Impressive!

 

[Conway Stevens]

Worked on the electronics and av bay. Love the switch holders Andrew makes through Additive Aerospace. sled is 3d printed by Skydancer. 3 altimeters, 3 batteries. 2 x 2s 300mah and 1x 1s 250mah. RRC2L, RRC3X and Raven 4. Redundancy with good data collection. Once i get my motor program back up and running i like the extra data for my own propellants.

 

[Conway Stevens]

Finally able to update this with a little time.

 

[Conway Stevens]

More progress

 

[Conway Stevens]

For the initial test flight i decided to use the Loki M1650 cocktail motor. Sims were close to 30k. Suspect will be lower as originally when i wanted to launch it. It was 98 to 100f. And now 60f. 40 degrees difference. Also winds were a little up at 12mph on the ground and higher above.

 

[Conway Stevens]

Finally got to fly it at Northern Colorado Rocketry Octoberfest launch. Flew on October 2nd.

 

[Conway Stevens]

Here is the boost. Really awesome flight strait as could be. Was pretty fast. Landed 200 yards fromthe flight line/ launch pad

 

[Conway Stevens]

I have a short video of the flight i will get uploaded and post.

Details of the flight
Had Featherweight gps tracking
Raven 4 primary and 2 RRC2L as backup
All collecting data
Flight was 28,142ft agl
Mach 2.6

 

[tim cubbedge]

Wow great flight! Congrats!

 

[DAllen]

Nice flight!

 

[rfjustin]

That's incredible, put something to 28K and have it land THAT close!

 

[Conway Stevens]

That's incredible, put something to 28K and have it land THAT close!

I honestly dont think i could do that again lol. I got lucky. Then called every name in the book by the flight line lol!!!