Lifting Bodies at MDRA

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Dr.Zooch said:
Intresting up-date here...

I took the 1977 shape and made several others with assorted changes. I test shot them over and over and today did it a bit more. Oddly, the one shape that consistently flew the best was... the exact 1977 original shape! No foolin' folks. Through altered fins and curved corners and differing angles, the final winner was the shape I'd developed in the months before I went away to college and spent a ton of money to learn about flying and aerodynamics. The only differance in the overall lifting body is the addition of a center fin to aid in avoiding adverse yaw.

Proves the old saying... if it ain't broke, don't fix it. Now if we could only teach web and software developers that lesson.
Click to expand...

AMEN and amen!!!! OL JR :)
 
So- I have the final shape for the kit- now comes the question of ballasting the lifting body. The problem here is that in most of my test shapes I used lead. But in the kit, the builders will be placing the ballast into the lifting body after they assemble the pieces- meaning that THEY will have to "handle" the ballast material. We all know how some people really freak out about handling lead- as if it were radioactive or something. So to avoid freak outs as well as law suits and recalls I'm once again going back to my original 1977 lifting body for the answer... BBs. Common BBs that you'd use in an air gun- they're cheap, easy to measure correctly, safe to handle and they fit well into the nose. Since the lifting body is fairly small, this should work well as an answer.

On another side-note, I took the oversized lifting body being used as a prop in the video and using the rubber band method launched it a few times at MDRA last Sunday. The first few launches were... well.. a bit unnerving. The thing really sails and does a huge loop when launched (Just as it does when deployed from the booster at altitude). Several times it bottomed out the loop and once nearly took my 17 month old daughter with it- even though I was standing about 75 feet away! I went farther out in the field... After some body flap adjustments, I finally got some flights out of it (foose4string can confirm that). My idea, however, was to get some in-flight video of it... but there was no way. The flights were too short and their path too unpredictable to catch any video.
I’ve just constructed a lifting body to kit instruction specs. And will now ballast it (as outlined above), then it will be used in flight tests- first to test out the adjustable body flap (which will be deleted if it does not have highly positive performance enhancement. Mainly because of cost and, most of all, the labor involved in placing it into the kits.) Following those tests I’ll test fly the stack on the selected booster. (See the booster choices in the photo)

1TRFlbb.jpg
 
Dr.Zooch said:
So- I have the final shape for the kit- now comes the question of ballasting the lifting body. The problem here is that in most of my test shapes I used lead. But in the kit, the builders will be placing the ballast into the lifting body after they assemble the pieces- meaning that THEY will have to "handle" the ballast material. We all know how some people really freak out about handling lead- as if it were radioactive or something. So to avoid freak outs as well as law suits and recalls I'm once again going back to my original 1977 lifting body for the answer... BBs. Common BBs that you'd use in an air gun- they're cheap, easy to measure correctly, safe to handle and they fit well into the nose. Since the lifting body is fairly small, this should work well as an answer.

On another side-note, I took the oversized lifting body being used as a prop in the video and using the rubber band method launched it a few times at MDRA last Sunday. The first few launches were... well.. a bit unnerving. The thing really sails and does a huge loop when launched (Just as it does when deployed from the booster at altitude). Several times it bottomed out the loop and once nearly took my 17 month old daughter with it- even though I was standing about 75 feet away! I went farther out in the field... After some body flap adjustments, I finally got some flights out of it (foose4string can confirm that). My idea, however, was to get some in-flight video of it... but there was no way. The flights were too short and their path too unpredictable to catch any video.
I’ve just constructed a lifting body to kit instruction specs. And will now ballast it (as outlined above), then it will be used in flight tests- first to test out the adjustable body flap (which will be deleted if it does not have highly positive performance enhancement. Mainly because of cost and, most of all, the labor involved in placing it into the kits.) Following those tests I’ll test fly the stack on the selected booster. (See the booster choices in the photo)
Click to expand...

Can I use LEAD BB PELLETS from my pellet rifle instead of steel BB's?? I just prefer to handle and use lead... I always straighten out those lead roof vents in the hardware store after people dent them and bend them up... makes you feel like Superman bending 1/8 inch metal plate with your fingertips...

:rotflol::kill::lol::rotflol: hehehe... OL JR :)
 
Visit junkscience.com and search lead.

Oddly- copper can be just as toxic... but don't tell anyone.

I'm illustrating the instructions now. Thank Art over at boostervision.com, he got me off my butt and back onto the track.
 
Looks as if BBs are going to be the best for ballast- they're working well in testing. I really like the idea of being able to alter the ballast 0.01 of an ounce at a time. Again- I had better ideas, I guess, back in 1977.
 
Nope- a cockpit does not offer enough weight to give the right balance, even if it could be built right on the nose. The cockpits on mine are all located on the CG because I like to balance first then modify with the cockpit.
 
Could be a late October release.

Meanwhile- I've been considering allowing the builder to do my rubber band launch method for testing of their own lifting bodies rather than simply using the toss method. The problem is that the RB launch requires that a small "talon" be cut from the balsa stock and glued to the nose of the lifting body. Then when the test flights are completed the talon has to be cut off and the area sanded down to allow the placement of the forward attach lug. Always looking for a slicker way to do things, I pondered the operation... Then the thought hit me- why not bevel the forward lug to act like a talon and serve both jobs? Would it hold the stress of the launch tension? Maybe if I put a ton of glue on it...

Doing my best NASA impression I generated 426 pages of technical documentation on the test and why it should be done, requested a budget from myself- requiring an additional 200 pages of documents, conducted a Test Readiness Review Board consisting of Me, Myself, I and an ant.

Then- I rigged it up on the kit-prototype lifting body and let it dry over the weekend... lots of Tightbound glue... yesterday, it was ready. I attached the rubber band and here in my office I did a static test... stretched the rubber band to the launch tension and... as soon as I got tension- ZING! the lug pulled loose and shot across the room. Another slick idea dies in my office. The lug, however, flew quite nicely.

1TRF_lugz2.jpg
 
Dr.Zooch said:
Could be a late October release.

Meanwhile- I've been considering allowing the builder to do my rubber band launch method for testing of their own lifting bodies rather than simply using the toss method. The problem is that the RB launch requires that a small "talon" be cut from the balsa stock and glued to the nose of the lifting body. Then when the test flights are completed the talon has to be cut off and the area sanded down to allow the placement of the forward attach lug. Always looking for a slicker way to do things, I pondered the operation... Then the thought hit me- why not bevel the forward lug to act like a talon and serve both jobs? Would it hold the stress of the launch tension? Maybe if I put a ton of glue on it...

Doing my best NASA impression I generated 426 pages of technical documentation on the test and why it should be done, requested a budget from myself- requiring an additional 200 pages of documents, conducted a Test Readiness Review Board consisting of Me, Myself, I and an ant.

Then- I rigged it up on the kit-prototype lifting body and let it dry over the weekend... lots of Tightbound glue... yesterday, it was ready. I attached the rubber band and here in my office I did a static test... stretched the rubber band to the launch tension and... as soon as I got tension- ZING! the lug pulled loose and shot across the room. Another slick idea dies in my office. The lug, however, flew quite nicely.
Click to expand...


I bet the Ant-stronaut Office is making ugly noises about unspecified modifications to the design... :rolleyes:

How about making a (darn can't think of the word-- those hooked sticks that cavemen used to launch their spears, that lengthen the arm moment and increase launch velocity-- dang it just saw it last week on one of the science channels...:eek:) Anyway, either using one of those to test launch the thing or adding a little hook-type chingaderra to the rubber band that will engage the launch lug... maybe a longer lug?? Seems like adding a launch strake to balance/test and then having to cut it off and get rid of the glue/mess on the bottom would mess up the balance, unless you carefully weighed all the crap cut/sanded off, subtracted the weight of the lug and glue, and then added the difference back to the nose in ballast... :p

Err... Well, whadda I know... you're the rocket scientist! Just thinking out loud! KUTGW! OL JR :)
 
luke strawalker said:
How about making a (darn can't think of the word-- those hooked sticks that cavemen used to launch their spears, that lengthen the arm moment and increase launch velocity-- dang it just saw it last week on one of the science channels...:eek:)

:)
Click to expand...

Atlatl, or in this case, Antlatl:p
 
Dr.Zooch said:
Doing my best NASA impression I generated 426 pages of technical documentation on the test and why it should be done, requested a budget from myself- requiring an additional 200 pages of documents, conducted a Test Readiness Review Board consisting of Me, Myself, I and an ant.
Click to expand...

So what did you do with the $400 million that was left over after the test?;)
 
Peartree said:
So what did you do with the $400 million that was left over after the test?;)
Click to expand...

Wrote myself a bill for $800M which leaves $400M unpaid which I'll be paying myself back at $4 per year, thus making myself a slow-pay customer on this project so in January I write it all off and if the IRS asks anything I can just say "Hey- I had a bad September... didn't everyone?";)

Keep in mind I used to be the pilot for the #2 guy at WorldCom- I learned well.
 
What about making the balsa test launch hook longer with a flat bottom that you attach the lug to?

The RBFED[1] (rubber band force exertion device) force is then exerted on the balsa instead of the lug, and there is no post construction CG changing.


Lyle

[1] I like acronyms made up on the fly.

launch_hook.jpg
 
Hey! I like that- as soon as the next flight test is over I'll give it a try!
 
JAL3 said:
Atlatl, or in this case, Antlatl:p
Click to expand...


YEAH that's it!!! I was thinking Adze, (or in this case ANTze) but I knew that was an ancient wood hewing device like a broadaxe... :rolleyes:

I'm getting old... Thanks Lee for a good pun! OL JR :)
 
Dr.Zooch said:
Okay... never mind... I'm installing the RBFED right now.
Click to expand...

I think you have the acronym associated with the wrong part. The RBFED is "the rubber band". The RBFED exerts force on the dual function extended launch hook/lug standoff. But then again one can say that the launch hook is actually exerting half the force against the rudder band.

The truck carrying the 8000 page request for $4,000,000 payment has been submitted. All three places for signatures are highlighted somewhere in there.


So I have to ask, on the sputnik kit, did you ever get a little foam ball and toothpicks in the kit to make your own sputnik?
 
Installation of the RBFED does add an issue to the lifting body in the area of the boost phase. Although it is seemingly small, the RBFED gives the lifting body a slight angle of attack when mounted on the booster. (see illustration) Depending on how you wiggle it on the mount, the AOA is between 4 and 9 degrees and is divergent from the intended flight path. What this equates to during actual boosted flight- could be nothing, could be really bad. Flight test will tell the story. My best thought is that it will mean nothing. I say this for two reasons. First, the onboard video of the Dr. Zooch Shuttle orbiter that was intentionally shot into heavy winds and sheer using an 18 mm D engine, clearly shows the nose of the orbiter moving up and down toward a similar divergent AOA of about 4 degrees with no real stability problems to the boost…

2TRF_aoa.jpg
 
Second... the cross-section of the lifting body itself as seen by the relative wind is actually more aerodynamically neutral than the zero AOA mount

2TRF_aoa2b.jpg
 
I've been following this thread with great interest!

My one-and-only boost glider was a huge kluge, made and flown when I was 17. I took the outer 1/3rd of the wings of a Guillow's Space Shuttle, mated them to a square-section no-compound-curves fuselage, and created a launch mount in place of one of the fins of a three-fin Estes Scrambler II. It was designed so that the parachute came out of the cargo area, and the with the shock cord attached externally to the motor mount, the glider would come off nice and smooth.

Toss-it-in-the-air-and-see-if-they-separate tests in my yard went great (the parachute always caused a separation), so I launched it.

It didn't work (the parachute door was held closed by aero forces. D'OH!) and came down without separating, crumpling the booster. It flew really straight, despite not having any sort of pitch control for the glider! The glider was mounted with only the aft two launch lugs for yaw control.

I got lucky; I think the glider went into a positive AOA in flight. This pitched the vehicle down which offset the pitch-up caused by the ugly draggy glider.




This is a great site! I've gotten a rocket itch for the first time in 20 years after reading about some scale rockets in the Nasa Spaceflight forums. I found and went to my local club's launch this past weekend! Nothing to fly yet, but maybe before the snow falls.
 
Wow! WELCOME to the forum! I'm flattered that you are reading this thread.
 
Here's a graphic showing the effective AOA as it applies to just the lifting body.

Note: For those who are wondering- Angle Of Attack is the angle between the cord line [an imaginary straight line drawn from the leading edge of an airfoil to its trailing edge] and the relative wind [as an object travels through a fluid mass, such as air, that mass strikes the object and the resulting force can be discribed as a directional flow- simply stated- a wind. This has nothing to do with the surface of the earth, it is strictly related to the directional motion of the object].

2TRF_aoa3.jpg
 

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