NASA X-59 Quesst Supersonic Aircraft (3D Printed Parts + Plywood Fins / Wings + Cardboard Bodytubes)

[BigMacDaddy]

In the last couple of days I decided to take a shot at the X-59. At first glance it seemed like there was not enough to turn into tubes -- that is my measure of how reasonable a rocket is to build as a semi-scale model (if I have to 3D print the whole thing it is likely pretty heavy, expensive, and time-consuming). Anyway, took a look at the X-59 again and had a bit of a breakthrough. I realized if I could angle a body tube in the mid-section of the rocket I could simulate the zig-zaggy angles of this interesting / beautiful plane (the tube would stick down below where the actual body is in the real thing but this would be below the wings so would be mostly hidden). The tube would also give me a place to put a parachute.

First a few pics of the real thing (hard to find pictures, lots of renderings online).




Here is my 3D mock-up (I posted some of these pics in the "What did you do Rocketwise today" thread. I used NASA's published 3D plans as well as another set I bought online as templates and wound up redesigning all the parts to accommodate the BT-60 body tube, a 24mm motor (and BT-50 motor mount tube), etc...



Here is the actual build so far (well just a mock-up / assembled set of parts at this point) - Orange Big Bertha for size comparison:







Some very interesting angles on this -- the motor is canted 5 degrees and the noscone is angled 5 degrees so motor is aligned with nosecone but NOT body tube. Planning a long launch lug in front of the tube and short one in the back so that thrust line will be parallel to launch rail. Not sure how it will fly -- arch over the top or over the bottom, fly parallel to tube or parallel to nosecone and engine...

 

[BigMacDaddy]

Everything below the red line does not exist in the real thing - but I think the wings hide it pretty well... I also had to make the jet intake larger since the BT-60 tube is proportionately wider than the body on the real thing (scale jet intake looked undersized).

 

[ReynoldsSlumber]

Very cool to see the CAD and prototype. You captured the look of the vehicle really well. Lots of non-axial geometry there!

Since you're turning a lifting airplane into a rocket, I wonder about it pitching backward as it flies, both under thrust and during coast. It might take a non-scale adjustment of aligning the wings and control surfaces to the long axis of the model. Or you could tilt the motor axis to be off-center and thus carefully balance the nose-down torque due to motor thrust with the nose-up torque due to the aerodynamic surfaces... but then once the thrust cuts out, only the aero surfaces would be acting. Maybe the wing and control surfaces could be carefully balanced in aerodynamic opposition? But hey, you got your NF-104 to fly impressively straight, I'm sure you'll make it work.

 

[BigMacDaddy]

Very cool to see the CAD and prototype. You captured the look of the vehicle really well. Lots of non-axial geometry there!

Since you're turning a lifting airplane into a rocket, I wonder about it pitching backward as it flies, both under thrust and during coast. It might take a non-scale adjustment of aligning the wings and control surfaces to the long axis of the model. Or you could tilt the motor axis to be off-center and thus carefully balance the nose-down torque due to motor thrust with the nose-up torque due to the aerodynamic surfaces... but then once the thrust cuts out, only the aero surfaces would be acting. Maybe the wing and control surfaces could be carefully balanced in aerodynamic opposition? But hey, you got your NF-104 to fly impressively straight, I'm sure you'll make it work.

Thank you... My mind sim is definitely overloaded here... The motor is aligned with the nosecone but the tube is doing some wonky stuff in the middle... Definitely possible it arches over the top or over the bottom (probably very likely since the wings are effectively angled 5 degrees compared to thrust line).

 

[ReynoldsSlumber]

Heh... If you keep the wings and motor angled as-is, you might be able to trim it out with the right horizontal stabilizer angle. Might even consider making the horizontal stab adjustable on the prototype, for fine-tuning the angle over several test flights.

 

[cls]

Really nice job with the 3D model. You even got the shovel nose. Yeah, a lot of weird angles on that one. I've been looking at it for a couple years, too hard for me, I'll wait for the PMC

 

[jqavins]

Thank you... My mind sim is definitely overloaded here... The motor is aligned with the nosecone but the tube is doing some wonky stuff in the middle... Definitely possible it arches over the top or over the bottom (probably very likely since the wings are effectively angled 5 degrees compared to thrust line).

View attachment 626374

A little (non-scale) cant of the canards could compensate for a lot.

 

[BigMacDaddy]

Successful flight yesterday of the NASA X-59 supersonic plane (BT-60 w/ 3D printed parts and plywood wings/fins) on a D12-5.

Very glad that it did not arch over the top or the bottom but it did some tail wagging for 2nd half of the flight -- I think it was spinning and the canted engine made it spiral a bit (tension between different angled surfaces may have been a factor??). I might have put a bit too much nose weight (2.5oz) in my effort to be stable. I am gonna launch it again with a bit less nose weight (1.5 or 2oz).

Any idea on reducing the tail wagging?

Here is the video: https://youtube.com/shorts/_MahlyEtS0U
Another angle: https://youtube.com/shorts/tLVoqiF7KVk



Also very glad that it missed that giant puddle / pond that is the result of lots of rain lately.



I did decide to mount this with one long rail guide in front and a short one in the rear. Not sure that affected the flight but it launched smoothly.

 

[burkefj]

Doesn't quite look like the overstable coning I see in pershings with too much nose weight, they don't speed up like that, hard to tell by the video, that motor is a bit soft thrust wise for the weight, you may try a higher thrust composite and see if it behaves differently.

 

[cls]

Great boilerplate!

Nice Natter there, too.

 

[jqavins]

Successful flight yesterday of the NASA X-59 supersonic plane (BT-60 w/ 3D printed parts and plywood wings/fins) on a D12-5.

Very glad that it did not arch over the top or the bottom but it did some tail wagging for 2nd half of the flight -- I think it was spinning and the canted engine made it spiral a bit (tension between different angled surfaces may have been a factor??). I might have put a bit too much nose weight (2.5oz) in my effort to be stable. I am gonna launch it again with a bit less nose weight (1.5 or 2oz).

Any idea on reducing the tail wagging?

Here is the video: https://youtube.com/shorts/_MahlyEtS0U
Another angle: https://youtube.com/shorts/tLVoqiF7KVk

View attachment 628781

Also very glad that it missed that giant puddle / pond that is the result of lots of rain lately.

View attachment 628779

I did decide to mount this with one long rail guide in front and a short one in the rear. Not sure that affected the flight but it launched smoothly.
View attachment 628780

Well, I sure hope the real thing doesn't wiggle like that with passengers on board.

Its negative pitch arcing is just what one might expect with the off axis thrust line. You might want to put more cant into the canards to counter it harder than what you've got. Or I might not know what I'm talking about. And there's no obvious (to me) reason that would be related to the conning, so I've got no guess there.

Also, it is actually conning, i.e. leaving a helical trail? Or is it fish tailing, i.e. wiggling only on the yaw axis; or "whale tailing", wiggling only on the pitch axis? The wiggle is visible from both camera angles, which suggests but does not prove conning, yet somehow it doesn't quite look right.

 

[BigMacDaddy]

Well, I sure hope the real thing doesn't wiggle like that with passengers on board.

Its negative pitch arcing is just what one might expect with the off axis thrust line. You might want to put more cant into the canards to counter it harder than what you've got. Or I might not know what I'm talking about. And there's no obvious (to me) reason that would be related to the conning, so I've got no guess there.

Also, it is actually conning, i.e. leaving a helical trail? Or is it fish tailing, i.e. wiggling only on the yaw axis; or "whale tailing", wiggling only on the pitch axis? The wiggle is visible from both camera angles, which suggests but does not prove conning, yet somehow it doesn't quite look right.

Thanks - the two camera angles are around 90 degree off each other (I drafted my family in to help with launched this time). The smoke trail seems to be a spiral as it drifts over close to the 2nd camera but difficult to tell.

By the way - found a good explanation for why an over-stable rocket tends to "cone" - https://info-central.rocketlabdelta.com/archive/design_coning.html

 

[BigMacDaddy]

Another pretty successful flight of my NASA X-59 Plane model rocket design. Less nose weight (1.5oz if I remember correctly) and an E12-6 engine (24" chute). I was trying to get the thrust line closer to the CG (bigger engine and less nose weight).

https://youtube.com/shorts/uInIq03KvAM

It still rolls quite a bit but I think there is less coning than before. It is quite possible that my wings are warped and this is causing the spiraling (these are big pieces of plywood) - I thought both were bent downward in the rear a similar amount but a difference here could be the cause of the rolling.

Parachute also decided not to open till about 5' from the ground but the rocket was fine (even the really long/thin nosecone that I was worried about).