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hornet driver

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Hello again everyone. I've decided to pull the trigger on the Pterosaur glider project. I've given this a lot of thought--still doing that---and have a plan --sort of !! I'd like you to follow along in this process , from design through the end. I'll be making some design decisions along the way so feel free to chime in and correct me if I get off course. It will be LP with a span of around 2.5 to 3 ft.I will use the paper mache clay in some parts of it. The goal is to have a realistic looking Pterosaur rocket boosted glider. I'll start posting design ideas in a bit---H
 
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Right off the bat I knew this was going to be difficult. I'll start by designing a glider and test fly a prototype. The first problem is--this is basically a flying wing with no vertical stabilizers . I need to design this wing to fly safely under power and I don't want a pod hanging off of it---HMMM. Let's start with the wing profile as seen from the front. I drew up three quick sketches and whittled down the choices.20150919_114651.jpg The top is great for a glider but the mean leading edge line is far above the thrust line( the motor is mounted in the body --the pink circle)---not great for launching under rocket power. The sketch in the middle is by far the worst. With no dihedral , side slip is a problem . But it does get the mean line closer to the thrust line ! I settled on the bottom profile. It puts the mean line at or near the thrust line and I can tweak the wing for stability. It's not perfect but it's a good compromise !!
 
Right off the bat I knew this was going to be difficult. I'll start by designing a glider and test fly a prototype. The first problem is--this is basically a flying wing with no vertical stabilizers . I need to design this wing to fly safely under power and I don't want a pod hanging off of it---HMMM.

How about having fins to represent the legs/feet?

BTW - Great idea! Can't wait to see it after that dragon you made! :D
 
OK, next I'll take a look at the wing as seen from above. I'd like this to look like the typical Pterosaur so the first profile was this20150919_114712.jpg This is really good for a glider but the long forward swept wings aren't going to work with the rocket. I'd have to add a ton of nose weight and the wings would still shred anyways( i see a potential flutter problem) Next I looked at this20150919_114719.jpg AHH, that's a little better. I'll add a little sweep. this should still glide good and it moves the CG forward without adding weight. In fact now it's somewhat of a tractor design and that should help with the stability under thrust ! I finally settled on this20150919_114703.jpg A little more sweep and a tail. It seems most Pterosaurs had tails so this sort of fell into my lap. One benefit of this project was the study I did on these creatures while trying to figure this thing out. Ya know there's around 205 different genera !Angustinaripterus_NT.jpg I'll start work on the protoglider tonight and maybe do some test flights tomorrow ! -H
 
How about having fins to represent the legs/feet?

BTW - Great idea! Can't wait to see it after that dragon you made! :D

I've thought about that and more than likely that's going to be part of the equation. I figure I could use clear plexi and paint the feet on
 
I've thought about that and more than likely that's going to be part of the equation. I figure I could use clear plexi and paint the feet on

Good idea!

BTW - I was actually thinking of suggesting a tail earlier, but figured a long one may be quite unwieldy on the pad and a short one may look odd.
 
Right off the bat I knew this was going to be difficult. (QUOTE]

"AH<REALLY... .what was your first clue...? " :cyclops:

What are you going to feed that thing?
Im thinking you may go REMOTE CONTROLL!!!!!!!! YA BABY!!!! That's it!
You can do it...:clap:

Anywhoo.....you do build some wild and far out sh1t dude!!!!!
 
Right off the bat I knew this was going to be difficult. (QUOTE]

"AH<REALLY... .what was your first clue...? " :cyclops:

What are you going to feed that thing?
Im thinking you may go REMOTE CONTROLL!!!!!!!! YA BABY!!!! That's it!
You can do it...:clap:

Anywhoo.....you do build some wild and far out sh1t dude!!!!!

I'm gonna let you down on this one--no RC-- it's just too small. The wings are big but the body is small. That said, if I can get the free flight version to work , I might be inclined to try a larger---don't know where I'm gonna put it !!--higher powered version later. I started on the protoglider tonight. I'll get some pics out in the morning. If the wind lays down a bit I'll give it a couple of tosses tomorrow. It's likely I'll do a couple different gliders to refine the shape. I'll try and keep the proportions as close to the real thing as possible. As a point of interest, these Pterosaurs were proportionally different than anything else on earth. Their measuring points---leg length, head size,joint to joint relation, are like nothing else. This gives them their unique look. I'll try and capture this in this project. There might be a fudge factor included .---H
 
Here are some pics of the protoglider. The wings are made out of foam board. After cutting out each wing I joined them together with a piece of foam board glued to the top. After this had set up I cut the grooves where the wing would be bent. Once in position I poured white glue in the groves and let it set overnight.20150919_215301.jpg. The center section was a bit larger than I wanted so this morning I cut about 3 inches out of it and repeated the process of joining them20150920_085737.jpg. Next I glued on a couple of dowels in the rear to mimic legs and epoxied on a foam body. 20150920_092307.jpg20150920_093921.jpg note there are no rudders or elevons
 
So it's off to the doggy park/test flight area. I took the foam head off(it would have been damaged) and replaced it with a wood dowel that I could slide in and out. There was a small piece of clay on the end of the dowel for ballast. First toss---STALL , I pulled the dowel out about an inch. Second toss---better with a stall at the end of the flight. I repeated the process with the dowel out about 2 inches. This gave me a nice straight flight. I repeated this several times with the same results. So far so good. It flew as expected. With no vertical stabilizers it did wander a bit but was less pronounced than I expected. Also with no elevons it flew straight but could not correct for downward flight direction. It's now back in the hanger getting these additions. CONFIG 120150920_100728.jpg CONFIG 220150920_100718.jpg---Both are viewed from the bottom. Remember this is a proof of concept not to scale model. The design will be tweaked as we move forward. More later--H
 
Ahhhh ,another one of your fine builds.Good to see you still at it.

Take care my friend !

Paul T
 
Ahhhh ,another one of your fine builds.Good to see you still at it.

Take care my friend !

Paul T
Thanks buddy, I haven't tortured myself enough lately. I modified the protoglider. It now has two small vertical fins made from card stock ,small stick on elevons and a longer front dowel. First toss with dowel in original position and two elevons up---short flight to stall. I suspected this would happen so on the next few flights I slowly worked the dowel out until it was about 6 inches out. It flew well in this configuration,also the small vertical tails straightened out the wandering yaw problem. On the actual rocket the tails will be clear. This glider is very close to the actual size of the rocket--corrections will be made for mmt sizing. Here are some pics20150920_133611.jpg20150920_133624.jpg20150920_134914.jpg the 4 pink squares are the elevons--I only used 2---The yellow square is the CG and the 3 green squares mark the relative position of the motor.The motor is well ahead of the free flight CG so it's added mass should help with powered flight stability. Also the longer neck profile will help with powered as well as free flight stability. Well that little part of the experiment is done . Now it's time to refine the profile a little ,retest, and build the rocket. This little glider has a 3 ft wingspan and weighs 1.9 oz I figure the rocket with balsa wings/paint/mache/ and mmt will come in around 7-8 oz. the higher wing loading "should" help a little with flight stability and increase flight speed. More later---H
 
Well, phase one is done and in the books. No real surprises but a lot of flight info to fall back on. Moving forward, I'll refine the shape a little closer to the one I want and test fly that. At the same time I'll work out the motor mount. It has to be able to eject with a streamer but be contained in a tiny space---love the challenges !!I'm already thinking about the finishing. It seems these guys had a furry surface so, I'm working out that detail now. I'm pretty confident I don't need the long tail for stability but I'll keep that option open for now. This is gonna put my build skills to the test. With fins/wings this big, everything will have to be near perfectly aligned. Here are some pics of what I'm looking forHatzegopteryx_BW.jpgOrnithocheirus_BW.jpgpterodactyl.jpgPterodactyl-facts.jpgpterosaur-picture-2.jpgpterydactyl1.jpg As you can see, I have a little room for styling points. ---H
 
Ok, gotta do it. Uncle joke.

Q: Why can't you hear a Pterasaur pee?
A: Because the "P" is silent.

thank my 11 year old son....

he's a bad influence.
 
that is really cool!!!! awesome!!



Thanks buddy, I haven't tortured myself enough lately. I modified the protoglider. It now has two small vertical fins made from card stock ,small stick on elevons and a longer front dowel. First toss with dowel in original position and two elevons up---short flight to stall. I suspected this would happen so on the next few flights I slowly worked the dowel out until it was about 6 inches out. It flew well in this configuration,also the small vertical tails straightened out the wandering yaw problem. On the actual rocket the tails will be clear. This glider is very close to the actual size of the rocket--corrections will be made for mmt sizing. Here are some picsView attachment 272518View attachment 272519View attachment 272520 the 4 pink squares are the elevons--I only used 2---The yellow square is the CG and the 3 green squares mark the relative position of the motor.The motor is well ahead of the free flight CG so it's added mass should help with powered flight stability. Also the longer neck profile will help with powered as well as free flight stability. Well that little part of the experiment is done . Now it's time to refine the profile a little ,retest, and build the rocket. This little glider has a 3 ft wingspan and weighs 1.9 oz I figure the rocket with balsa wings/paint/mache/ and mmt will come in around 7-8 oz. the higher wing loading "should" help a little with flight stability and increase flight speed. More later---H
 
At the same time I'll work out the motor mount. It has to be able to eject with a streamer but be contained in a tiny space---love the challenges !! ---H

Der MicroMeister talks about using Teflon tape wadding, would it be possible to use a Teflon streamer? Maybe attached with a wire through a tiny hole (hide your eyes, NAR code purists) drilled through the end of the motor. Since you won't need wadding, could tuck your streamer right up against or even slightly inside the forward end of the motor casing. How much of what you are ejecting is motor and how much is mount? May not need much streamer if it is very light end engine hits ground first.
 
You might want to model the fin on the head on your dowel glide tests and make sure your lateral stability is still ok, you may need to upsize the feet/vertical fins for that..looking at the marston pteroworks it has pretty large V tail surfaces.
 
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You might want to model the fin on the head on your dowel glide tests and make sure your lateral stability is still ok, you may need to upsize the feet/vertical fins for that..looking at the marston pteroworks it has pretty large V tail surfaces.
Ya know,you might be on to something! The fin thinggy on the head is actually quite small and not a flat faced fin, BUT! under glide conditions the head on a long neck would exacerbate any yaw problems I might have. GOOD CATCH!
 
I'm not familiar with rbgs, but...

Alternatively, how about enlarging the vertical fins by doubling them and having the same on the bottom...you can have the top ones clear and paint legs on the bottom ones. Rocket-wise, it seems better to have the fins on both sides. :)
 
I'm not familiar with rbgs, but...

Alternatively, how about enlarging the vertical fins by doubling them and having the same on the bottom...you can have the top ones clear and paint legs on the bottom ones. Rocket-wise, it seems better to have the fins on both sides. :)
Likely the direction I'm going in.
 
All this is inspiring me dig out the old Desolation of Smaug design I was working on a while back. Three canted motors in the back of the head and a flexible tail. No glide because that takes real skill, just lots of thrust will have to do. Maybe I will call it the Decimation of Smaug, a fire breathing monster rocket, the CRASH guys will love that. Would love to see this one fly good so I won't be so scared to build a Smaug. Monster rockets rule!
 
I finally started putting glue to wood. The first thing was to warp a piece of 1/32 balsa into a close approximation of the wing profile. This is really thin stuff and I immediately split one end taking the sku sticker off. Not to worry, it will be covered. I soaked the wood and then placed it in my brand new high tech peanut butter /water bottle wing warping jig. I let it set for a couple of days--- it came out about right--a little over warped but that's what I wanted the layering process will begin to take some of that out!!--[url=https://flic.kr/p/AikTA4] --I'm going to plank the top and bottom with 1/16. After the entire blank is done I'll cut out the wing shape.--[url=https://flic.kr/p/zktken] --[url=https://flic.kr/p/zktjXR] --this is gonna take some time !!
 
Once I get the wing shape cut out of this blank , I think it's a good bet that I'll go back over the top and bottom with a sheet of 1/32 to stiffen it up. It still has a bit too much flex for me span wise. Although, in all other directions the flex is minimal.
 
More sheathing.

Looks like.......um,......ahh, well,. ah..... a bent piece of wood. :tongue:

Anywhoo..Im waiting for a good pigment day on the weekend. Got me RockStar ready for pigment and want to apply some pigment to a sratcher also. And on me Tesla.
 
More sheathing.

Looks like.......um,......ahh, well,. ah..... a bent piece of wood. :tongue:

Anywhoo..Im waiting for a good pigment day on the weekend. Got me RockStar ready for pigment and want to apply some pigment to a sratcher also. And on me Tesla.

Yes !! But it's a structurally sound ,technically innovative, and masterfully bent piece of wood !! OK, so I'm a long way from pigment:facepalm:
 
I'll be interested to see how straight you can keep it, it seems like it would be easy to get a twist, but i'm overly conservative when I do gliding things but i'm interested in this.
 
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