Hello Darling - An L1000 Submin to Mach 3 and 30,000ft.

[tsbooska]

This thread is for putting information on this rocket out there into the TRF community. I have been documenting this thing in the r/rocketry community for the past 4 months or so, and I figured I'd make a thread here as well to share information and ideas. First off, a snapshot of the rocket in its current form. It's flying to 30k and Mach 3 this Saturday at TRAPHX!

 

[tsbooska]

This rocket started maybe 8 months ago when I started cooking up Openrocket designs. I then back burnered it for a while to work on some other projects, and came back to it. I built a rev. 1 that got launched in early October at FAR, where it snapped the Wildman nose cone in half at about Mach 2.6-2.7. I found it, and everything else was attached, including fins that I painfully tip to tipped in carbon, and a mostly-intact but not quite salvageable av bay.

 

[tsbooska]

I then put rev. 2 on hold for a couple months to work on a couple other projects, including a pretty sendy 2 stage team project at TRAPHX. Then, in winter break, I re-designed the rocket and got to work on the rev. 2. This one features a much-reduced av bay section, a custom FG nose cone, thicker plate fins with no t2t, and machined transition, nose tip, and tailcone parts. The motor serves as the nose cone coupler for a wildly stiff joint. The electronics on board are an Easymini and a Featherweight GPS. The lot hasn't failed me yet, so I figured I'd push it a bit. The charges are of the tfish vinyl tube design.

 

[tsbooska]

First, fins. They are 4mm carbon plate with eyeballed bevels on a belt sander. Nothing special here, just a set of reasonably well made fins that constituted about 3 hours of work. They were then tacked on with some 5 minute using some little jiggy bits.

 

[tsbooska]

Next are the fillets. I splurged a bit on some Loctite 9462, a 250F room temp cure epoxy with wonderful structural properties. 10/10 mouthfeel, would highly recommend. I used the world's filleting supply on these things, and well, I don't think these fins are coming off.

 

[tsbooska]

Next up was the nosecone, another dumb simple to execute operation, using 5 layers of Soller 3K fiberglass sleeving over a 3D printed mandrel. Condoms for mold release of course, and this thing is terrifyingly strong. I don't think this thing is blowing up any time soon.

 

[tsbooska]

Next up is this little micro avionics bay, which sits on top of the motor, and is held on by a 1/4"-20 rod, which is in a 3/8NPT plug in the motor. It isn't load-bearing, so it's another of my certified jank PLA prints. Top bulkhead is laser cut with about 5 minutes of effort, and the whole thing is covered in a PLA shell to protect from... bird poop?

 

[tsbooska]

Finishing up the nose cone is this massive Al tip that I got made by JLCPCB for far too few dollars. It's retained with a washer and eyebolt. The whole thing is a chunky beast, but is the strongest nose cone of this size that I've flown. I'd probably trust it to M3.5-4.

 

[tsbooska]

That pretty much brings us to now. The whole thing was built in about 2 weeks with extreme care given in certain places, with a little looser attention on others. Surface finishes on the nose cone and fillets aren't great, but the avionics and recovery are solid, and the aerostructures are certified tanks. This rocket in its current form sims safely to about 30k and Mach 3, which I believe should be one of the highest, if not the highest L1000 flights out there.

Feel free to ask any questions, state any concerns or ideas, and generally hang out below!

 

[rfjustin]

This thread is for putting information on this rocket out there into the TRF community. I have been documenting this thing in the r/rocketry community for the past 4 months or so, and I figured I'd make a thread here as well to share information and ideas. First off, a snapshot of the rocket in its current form. It's flying to 30k and Mach 3 this Saturday at TRAPHX!View attachment 625909

How does the tailcone interface to the nozzle? Was the 3d printed aft ring removed?

Good luck with the flight!

 

[tsbooska]

How does the tailcone interface to the nozzle? Was the 3d printed aft ring removed?

Good luck with the flight!

The thrust ring is popped off with a little bit of force and a dream. The tailcone is just a thin Al shell that's epoxied on with a pretty thin bond to the aft of the case. It doesn't touch the nozzle.

 

[kjhambrick]

Beautiful ( especially those fillets ) !

Q: Is the nose cone diameter just a tad greater than the motor case ?

Or is that an optical illusion ?

Q: What is the annular ring at the nose / motor joint ?

Thanks for posting @tsbooska !

-- kjh

 

[Spacemo]

I did a similar build a few years ago. It didn't go straight up but only made it to 17,560 feet at Mach 2.5. Not the most aerodynamic fins but they stayed on

 

[StreuB1]

neat

 

[Porkchap]

Next up was the nosecone, another dumb simple to execute operation, using 5 layers of Soller 3K fiberglass sleeving over a 3D printed mandrel. Condoms for mold release of course, and this thing is terrifyingly strong. I don't think this thing is blowing up any time soon.

Well, one problem I see are those almonds. Should be the Wasabi and Soy Sauce flavor. They are freakin' awesome, and I don't even like Wasabi.

 

[tsbooska]

Beautiful ( especially those fillets ) !

Q: Is the nose cone diameter just a tad greater than the motor case ?

Or is that an optical illusion ?

Q: What is the annular ring at the nose / motor joint ?

Thanks for posting @tsbooska !

-- kjh

A: The NC diameter is bigger. The NC slides onto the top of the motor and uses the motor as a giga rigid coupler. Very much a fan of this setup.

A: The annulur ring is what the nose cone rests on such as to not jam itself.

Thank you for the kind words!

 

[tsbooska]

Success! Tailcone fell off and surface finish wasn't epic so it only went about 21.5-22k / 30k, but went pin straight and everything is perfect with little to no rash. Photos are by Matt Dahle. Recovery was nominal, landed at a bit over 30 ft/s. It landed only 3600ft from the launch site, a quick walk. Plenty excited about this, now onto even scarier rockets.

 

[Porkchap]

Me: "Woooo! Just flew my rocket to over 12,000 feet! and Mach 1.5!!"

This guy: "Aw, that's adorable. Hold my beer..."