Whose gonna knock this one out of the park first? X-59

[BABAR]

https://en.wikipedia.org/wiki/Lockheed_Martin_X-59_Quesst
Hmmmm, not sure if @mbeels , @neil_w , @burkefj , or @lakeroadster or some other talented craftsman is gonna have a go at this. Might even get @hornet driver back into the game!

 

[bcook7135]

Wow!

 

[neil_w]

@mbeels is the one who has actually done this sort of thing before with his build of the Boom XB1: https://www.rocketryforum.com/threads/boom-xb-1.160102/

Definitely worth checking out that build thread if you haven't seen it before.

 

[DigBaddy]

ooooohhhhh!

 

[mbeels]

That's wild! "low decibel thump".

I can't imagine what forward visibility during landing is like. Yikes.

 

[neil_w]

I can't imagine what forward visibility during landing is like. Yikes.

Non-existent? You couldn't even see *forward* from that cockpit. The whole thing has to be camera-based.

 

[smstachwick]

Non-existent? You couldn't even see *forward* from that cockpit. The whole thing has to be camera-based.

I could see a number of possible solutions. Early monoplane fighters like the Brewster Buffalo had ventral windows to double-check landing gear configuration and for level bombing.



They may also rig up a Concorde Droop.



For the technology to be applied to an SST, I’m going to bet that the FAA will have pretty strict regulations about power delivery and lens protection for a safety-critical in-flight camera system. Unless, that is, Boeing ends up manufacturing it

 

[neil_w]

https://www.thedrive.com/the-war-zo...ll-have-zero-forward-visibility-for-its-pilot

 

[mbeels]

Interesting article: "“Well, the FVS [forward vision system] camera’s on the bottom, so they can actually kind of fill in that whole picture and make it look like I don’t have a nose on the airplane at all.”"

 

[burkefj]

I personally hate the look of this design, even if it will do what they designed it to, just too busy to my eye..

 

[lakeroadster]

Looks like they took a standard jet, stuck it on a Delta Wing, then took the nose and stretched it.

​

 

[cls]

https://estesrockets.com/products/low-boom-sst

... sorta

 

[BABAR]

Of course, now that I look at it, @mbeels has built almost the exact thing already, in fact it may be a prototype.

https://www.rocketryforum.com/threads/boom-xb-1.160102/page-8
post 220.

of course, AFTER I wrote this, I went back and saw @neil_w had already noticed this.

 

[neil_w]

Of course, now that I look at it, @mbeels has built almost the exact thing already, in fact it may be a prototype.

It’s not a prototype. The two are unrelated as far as I know.

They do sport a similar overall shape, though.

 

[BABAR]

It’s not a prototype. The two are unrelated as far as I know.

They do sport a similar overall shape, though.

a columbine by any other name....

 

[mbeels]

I personally hate the look of this design, even if it will do what they designed it to, just too busy to my eye..

The proportions are a little odd, probably because designing for a low decibel thump took precedence over other considerations.

It's like a Spoonbill and a Platypus had a supersonic baby airplane.





But it could be a fun modeling challenge.

 

[c0c0m0ke]

I have been working on a design of my own, inspired by a”Dave Leninger” ( I think I spelled his name incorrectly). Any way, I am having a problem devising a fail proof recovery system.
The problem is the fairing. The whole rocket is a fairing, but not a conventional fairing. My phone doesn’t have the storage to allow me to upload a photo what it looks like. I will try to describe it.
It has 6 sides or faces. Each face is a parallelogram shaped like a diamond. If one matches one of the sides up tip to tip to two other sides and connects them with tape you get a funky looking pyramid on stilts. Do the same with the other 3 faces, that half will fit into the other half, the result is a long flat and angled pseudo cylinder. (I hate my phone because I have to do this - I can’t load the picture unless I dump some apps). Imagine the rocket tube threads thru the center. 2 plywood equilateral triangles act like centering rings pushing out the sides of the fairing. The middle is where the tube breaks and separates the top half from bottom half. Near the separation - both tubes have a funky hexagon serving as another centering ring. If the break was exactly in the middle, I imagine the hexagons would be nearly identical. A launch lug runs the entire length of the tube. The forward end of the LL emerges thru the seam where two of the faces are joined. All 3 sides trap the nose cone. Between the front tip and nose cone, an ounce of bb’s are hot glued in place to add stability. The aft end of the LL comes out the back.
For recovery, I have a 36” shock cord threaded thru the fins attached to a 24” chute, while the top half has a 6’ long but much thinner shock cord threaded thru one if the sides but wrapped around all of them and collected together on the inside of the fairing.
I Tested it the day before I was gimping to try to fly it. Not so good.
The charge was probably too much. 29mm motor tube about 25” long, burst between the forward “centering ring” and the nose cone. One of the faces detached from the rest of the fairing and tow of the side cracked near where the tube ruptured. The top 3 sides were glued to the nose cone but after the test, only one side remained glued. I was told flat surfaces don’t handle pressure as well as round ones.
I want the two halves to separate. As I was describing the parachutes being loosely folded together - I was informed that wasn’t a good idea. I figure the aft end will tumble if the parachute doesn’t open. The front end is heavy and not inclined to tumble, gravity is more likely to pull the two away from each other and promote deployment of both parachutes.

 

[kalsow]

This rocket?

https://commons.wikimedia.org/wiki/File:Silver_Polygon_Rocket.jpg

 

[neil_w]

Please tell me there are more (and better) pics of that rocket somewhere. My initial searching didn't turn up anything, at least not under that name.

 

[kalsow]

Please tell me there are more (and better) pics of that rocket somewhere. My initial searching didn't turn up anything, at least not under that name.

It was the rocket on my Tripoli membership card a year ago.

I believe Dave may have posted some pictures on the UMERG facebook group:

 

[Rschub]

I need to stop looking at this site when I'm bored, stuff happens...




This looks pretty close except for the fins.

 

[jqavins]

Hey, Neil, how would you craft a piece of tube that morphs from a triangular cross section at one end (a la a triangular prism) to circular at the other end (a cylinder).

I'm thinking one could build that rocket above, but without fins, and with rectangular extensions from the bottom three edges that form a triangular prism section. Size that to be a shoulder, going into a slightly larger triangular tube. Then, moving along down, add the transitional piece described above to morph into a regular tube, and you've got a funky nose "cone".

 

[neil_w]

Four possible approaches:
1) 3D printing
2) Cardstock
3) Thin balsa sheet (1/32" would work, depending on the smallest radius)
4) planks

Options 2, 3, and 4 would require cross-sectional pieces to set the profile periodically along the length of the "tube". CAD would be very helpful for this. @mbeels's Boom XB1 used option 4. John Boren also did a crazy one in the past using this method, sorry no link at the moment. I think that models with this sort of construction present an extremely interesting area of exploration, since they really let you get away from the same-old cylindrical airframes, but without needing to resort to composites. But it's a much different design process; OR not much help for this sort of thing.

 

[mbeels]

I'm thinking one could build that rocket above, but without fins, and with rectangular extensions from the bottom three edges that form a triangular prism section. Size that to be a shoulder, going into a slightly larger triangular tube. Then, moving along down, add the transitional piece described above to morph into a regular tube, and you've got a funky nose "cone".

Hey Joe,

I'm trying to picture this, but I can't quite follow the details. Any chance you can draw a picture?

 

[OC-Patrick]

...kinda looks like Stine's Antar rocket by Estes.

 

[kalsow]

Begin retired.... I spent the day measuring various photos of Dave's rocket and writing an OpenSCAD script to model it. The script and an STL are attached. Enjoy.

I'll probably see Dave at the launch this weekend. I'll try to remember to ask him if there are any better measurements.

 

[jqavins]

Hey Joe,

I'm trying to picture this, but I can't quite follow the details. Any chance you can draw a picture?

Probably not very well.

OK, here's the picture from post #21 with the fins cropped off.

Remember that the cross section at the base is an equilateral triangle.

Now, add rectangular extensions to the bottoms of those three panels, bent out of plane with the rest of the panels so that they form a bit of triangular tube.

If I were making a triangular rocket, that blue part would be the shoulder for the nose, and I'd be done. But no, I want to transition that to a regular round tube that will hold the motor mount, fins, laundry, etc. So, next make a special transition section that goes from this triangular cross section to a round one, sized for the blue part to be the shoulder which goes into the front end of that.

Then add a coupler to the circular end of the transition to serve as a new shoulder, and this whole thing is your nose. Where I say the geometry is TBD, I know it's a solved problem and the solution can be looked up.

Bonus points if you can remove the top three panels to open the grey section as a payload compartment.

You know how a triangular thrusting blade makes wounds that don't close? This could be the head of an especially vicious and deadly spear or arrow.

 

[mbeels]

Then add a coupler to the circular end of the transition to serve as a new shoulder, and this whole thing is your nose. Where I say the geometry is TBD, I know it's a solved problem and the solution can be looked up.

Ah, ok, got it, thanks. Those pictures definitely helped me picture it.

I think if I were to build something like that, I'd do the entire rocket with a triangular cross section, there could still be a round tube inside that triangle for motor mounts and couplers. The nose cone would have a triangular outside, with a cylindrical coupler, and the body would also have a triangular outside, with a cylindrical body tube within.

I think that the cleverest triangular and square body tube sections were @BABAR 's rockets with the side planks that pop up and become the rotors after ejection. That's neat.

 

[BABAR]

.

 

[BigMacDaddy]

Hey, Neil, how would you craft a piece of tube that morphs from a triangular cross section at one end (a la a triangular prism) to circular at the other end (a cylinder).

I'm thinking one could build that rocket above, but without fins, and with rectangular extensions from the bottom three edges that form a triangular prism section. Size that to be a shoulder, going into a slightly larger triangular tube. Then, moving along down, add the transitional piece described above to morph into a regular tube, and you've got a funky nose "cone".

Now that I am learning Fusion 360 these types of things turn out to be relatively easy to do via 3D printing... There is a function called Loft that morphs any shape into any other shape (also exists in Blender -- which is free but Loft function does not seem to be as good in Blender). It can be more difficult to make this look good with more complex geometry on either or both sides. Still needs shoulders of course...