Sunward Glider Flying Model Rocket questions

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Kirk G

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As mentioned elsewhere here, we tried to nail down the A2-2 motor question, and have determined its not available to me, but I do have a pack of A8-3 and the recommended B4-2...so I think I'm good to go for an initial flight and a few other attempts at the next club flight next weekend.

Since I can't sleep, I opened the package and I've started assembly of the motor tube and noticed a few things. The laser- cut fins/wings have mostly all separated from the chaff or excess while still in the package. There appears to be no damage, no loss, nothing missing. But I'm saving the excess for ballast.

The instructions are both in English and French, so it's bizarre reading them interspersed. But doable.

The first question has to do with glue. I am in the habit of using yellow carpenter's wood glue on my rockets...balsa fins, and assembly, except when CA or plastic epoxy or something exotic is specified. THIS kit mentions white glue in the list of required materials (along with a list of the usual suspects...sandpaper, hobby knife, cellophane tape, etc.) and I've not run into this before.

IS WHITE GLUE SPECIFIED FOR SOME UNUSUAL PROPERTY....like lighter weight, or recommended for gliders....as opposed to YELLOW CARPENTER'S GLUE? Both glues are available to me, and are the Elmer's brand. I also have access to Titebond No-Drip wood glue too, and a bottle of thick CA for hobbists.

Is there anything I'm missing about this white glue...or is it just that was the industry standard back in 2005 when this kit was produced?

**(I'm a little skittish of white glue, 'cause in my very first rocket, I used white glue to attach the fins, and it turns out the tube was left over from some silly pressboard shelving unit. The paste/glue never set up as well, and lacked the strength of yellow glue. One at at time, the fins snapped off with each attempted flight. I learned my lesson and pitched that tube of white glue paste.)
 
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I think white glue is more common or accessible to people who do general arts and crafts. Yellow glue is more "professional" or specialty product. Anyone who knows about yellow glue knows about white glue, but the inverse may not hold.

Perhaps the instructions cater to the wider audience that may be unfamiliar with yellow glue. If you use yellow glue normally, I can see no advantage to using a softer, weaker white glue.

Ari.
 
Just use Yellow Glue.

In this Sunward Rocket Glider kit from 2005, there's a six page set of directions, written in English and alternating with lines in French. This takes up a lot of space, as you might imagine. But there are diagrams and a few close-up photos. This also means some lines of instruction are necessarily shorter.

When starting on the 8" body tube, the first instruction tells you to remove the non-square rudder piece and glue it to the side of the body tube, flush with the end. Very good. (I used yellow glue.) The next instruction tells you to glue to launch lug to the other side.

There is no master photo or drawing of the finished rocket/glider that shows this, nor any measurement of where to place it. It's pretty clear that they want it glued 180 degrees away from the rudder (on the other side) but am I to assume that the launch lug is also to be flush with the end, as the rudder piece was? Should it be slid up higher on the body tube? I would think if this were a standard rocket, the lug ( or two) would want to be more centered, but I understand that there's going to be a glider dangling or attached behind/below it, and so, I'm thinking perhaps the launch lug is not in a "standard" place.

Comments?
 
3rd Question: Why is there a streamer recovery system? This is a rocket boost glider, and I understand the glider will separate from the rocket booster, then an escape charge will deploy...what? There's a 1" streamer included.
Would a 12 mylar plastic chute not work?

Which do you use? Or is there much difference?

How do you attach the streamer to the nosecone? The blown plastic nosecone has a tiny, small 1/32 hole drilled into it as a securing location...but the fat 1/4" rubber shock cord certainly won't fit through it. Should I try putting a swivel through the opening in the plastic, and then tie the rubber shock cord to the swivel? How to you secure the streamer once it's inserted into the body tube? Or is it? Just roll it up in a roll, or folded back and forth?

I understand the booster uses FOUR wadded up sheets of recovery wadding. But having little to no experience with a streamer, is that enough to protect the streamer if it just sets atop the shock cord?

Any advice welcomed.
 
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After working on and off on the glider all afternoon, I finally found the missing bottle of CA and coated the bottom of the rudder, to strengthen it and protect it. Since the wings and stabilizer are glued on, I took it out in the calm, humid air for a test glide... and found that it tends to stall. The instructions said to add weight in the form of some of the scrap wood, to the front...and I also added a drop of yellow glue to the front for weight and as it dries, I'm about to try the final test glide of the day.

Took a chunk out of the scrap and glued it with CA on the nose. Not aerodynamic, but some additional weight. The glider doesn't stall as much, but still does. And so I snapped a photo or two with a digital camera to show the work bench/table and wanted to show the status. But the disc doesn't load and it says the chip is not formatted. So I'm stumped.

Also, I started to spray paint the booster portion with white primer, and then a finish coat of white, but it's having a hard time drying. So I guess I'm about stalled for the day. Might put a few stickers on the wings but I'm breaking for dinner and bed.
 
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This is a skill Level 5 monster. I tried to launch it twice, both times an unmitigated disaster. Only bilingual, hardened and vastly experienced boost glider competitors at the highest level should even open the package. Do you have the perfect airfoil? Do you have a custom and full proof attachment scheme? Is it trimmed to perfection? Is it precisely 3:24 PM when you have calculated the thermals arising off the parking areas? If any of these questions are problematic you don't have the skill to master this kit. I bought mine off EBAY for $.99 U.S. plus shipping. No one bid against me. They were the smart ones. Time to get a Sunward Pyramid, space ship or airplane rocket. Tons of challenging rocket flying fun from way up North. When it comes to flying them I couldn't read the French, and the English instructions left it to the builder to get the balance and power right. Put on the helmet with the blast shield down. Reach out with your mind, use your feelings. Its almost as if you can actually see it flying right. Yes, you have just taken your first step into a larger world. May the Force be with you.
 
This is a skill Level 5 monster. I tried to launch it twice, both times an unmitigated disaster. Only bilingual, hardened and vastly experienced boost glider competitors at the highest level should even open the package. Do you have the perfect airfoil? Do you have a custom and full proof attachment scheme? Is it trimmed to perfection? Is it precisely 3:24 PM when you have calculated the thermals arising off the parking areas? If any of these questions are problematic you don't have the skill to master this kit. I bought mine off EBAY for $.99 U.S. plus shipping. No one bid against me. They were the smart ones. Time to get a Sunward Pyramid, space ship or airplane rocket. Tons of challenging rocket flying fun from way up North. When it comes to flying them I couldn't read the French, and the English instructions left it to the builder to get the balance and power right. Put on the helmet with the blast shield down. Reach out with your mind, use your feelings. Its almost as if you can actually see it flying right. Yes, you have just taken your first step into a larger world. May the Force be with you.


It isn't THAT hard, but there is an art to it. The biggest thing is that you make sure that the dihedral is at least as high as the kit says. A little higher is better, lower will make you throw the glider under your car's tire and drive back and forth.
 
It isn't THAT hard, but there is an art to it. The biggest thing is that you make sure that the dihedral is at least as high as the kit says. A little higher is better, lower will make you throw the glider under your car's tire and drive back and forth.

Gee, I could have used that advice about one day earlier. I just guestimated 18 degrees. Hope I got it larger than that.
 
It isn't THAT hard, but there is an art to it. The biggest thing is that you make sure that the dihedral is at least as high as the kit says. A little higher is better, lower will make you throw the glider under your car's tire and drive back and forth.

I guess I am just good at the art of burning it up on the pad and throwing it under the car's tire.:eek:
 
Gee, I could have used that advice about one day earlier. I just guestimated 18 degrees. Hope I got it larger than that.

18 degrees should be plenty. I find that 15* is a minimum for free flight, 10-12* for 2-ch R/C, and about 5*-6* for full house R/C. These are general heuristics, and a full aero analysis will give you better results.

For getting the dihedral right, I use simple trig. Need 18* on a side? That puts a 36* angle between the wings. SIN(x) = opposite/hypotenuse; in this case, hypotenuse is the half span of the flat wing, and opposite is the distance you need to raise the tip off the table to get the right dihedral. For our example, lay one wing flat on the table and raise the other SIN(36*) = 0.587, or about 9/16" for every inch of half-span. You can measure after the fact and do the reverse calculation: DIHEDRAL = ARCSIN(tip_height/half_span), to check your numbers.

If you find that the dihedral is less than desired, let me know and I'll give you a way to fix it.

I guess I am just good at the art of burning it up on the pad and throwing it under the car's tire.:eek:

We all have our days. Some more than others apparently.
 
OK, I gotta ask: How did it burn? Did it cato?

It was a couple of years ago so the pain and emotional scars have healed with time. I can't at the moment remember what exactly went wrong on the first flight, I think the glider came off early and the ejection charge slightly burned the naked tube as it hit the ground. On the second flight the attachment holding on the glider failed right at take off. The wing went into the path of the motor flame and the whole thing just flew apart and went into an unstable twisting mess. The glider is still on the shelf of shame with a burn streak across its wing. The tube was toasted beyond repair. No need to push the Three Strikes and you are out rule so I started scratch building safe and sane airplane rockets.
 
18 degrees should be plenty. I find that 15* is a minimum for free flight, 10-12* for 2-ch R/C, and about 5*-6* for full house R/C. These are general heuristics, and a full aero analysis will give you better results.

For getting the dihedral right, I use simple trig. Need 18* on a side? That puts a 36* angle between the wings. SIN(x) = opposite/hypotenuse; in this case, hypotenuse is the half span of the flat wing, and opposite is the distance you need to raise the tip off the table to get the right dihedral. For our example, lay one wing flat on the table and raise the other SIN(36*) = 0.587, or about 9/16" for every inch of half-span. You can measure after the fact and do the reverse calculation: DIHEDRAL = ARCSIN(tip_height/half_span), to check your numbers.

If you find that the dihedral is less than desired, let me know and I'll give you a way to fix it.
SAM_0054.jpg
Looking at the bird, nose on, it's pretty clear to me that I have substantially less angle on the right side (left wing) which I had to overlap to get enough surface area on the boom to adhere. So, after gluing it on with yellow carpenter glue, how do I modify this, assuming that it won't fly. Tests so far show it stalls, but does not describe curves nor spirals with just a light push.

I also decided to hedge my bets, and began cutting out a replacement stablizer from scrap balsa (that my daughter happened to have!) except that it is twice as thick as the original piece, and I glued a straight seam right down the middle along the grain, figuring that I could feather and shape this and smooth it out a bit more starting with a thicker piece. But I haven't gone any further than cutting it out to size.
(Remember, this was the stablizer that I unfortunately shaped when it was flipped, and so, the airfoil was upside down. By the time I had righted it, and shaped it, it was so wafer thin that it was physically smaller than it's twin. Not sure if it is affecting flight yet, as I'm still working on the stall issue. Hmmm...could they be related?)

So, though I am 'tuning' it by gentle glides, the proof in the pudding will be at the club launch this weekend with an A8-3 and three B4-2 to play with.

Please, give me your suggestions on solving or fixing the 18 degree issue, if you can. I'll try to post pics tomorrow to show the status. No chance of working on it again until then. I'll be free after noontime and at home, so I can snap pics and post then.

PS: I gave the booster tube a single coat of gloss white Monday, and aribitrarialy sprayed the blown white nosecone gloss red, as I had the dregs of a can, and...well I LIKE red nosecones. Plus, if the streamer comes off or separates, I want a visual clue on where each part went.)
 
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Before we do anything, let's do a couple of quick measurements. Measure the half-span (fuselage to wing tip along the wing). Measure also the distance that one wing tip sticks up if you lay the other flat on the table. To the nearest 1/16" or 1/8" should be sufficient.

If you haven't glued on your stab/replacement stab yet, don't. We may be able to "fudge" it a little to make it work.

As they say, a picture is worth a thousand words, so I would suggest waiting till we have a good look at your problems. They may not (or may) be as bad as you state.
 
Before we do anything, let's do a couple of quick measurements. Measure the half-span (fuselage to wing tip along the wing). Measure also the distance that one wing tip sticks up if you lay the other flat on the table. To the nearest 1/16" or 1/8" should be sufficient.

If you haven't glued on your stab/replacement stab yet, don't. We may be able to "fudge" it a little to make it work.

As they say, a picture is worth a thousand words, so I would suggest waiting till we have a good look at your problems. They may not (or may) be as bad as you state.

The measurement of the wing from fuselage to wingtiip is 7 inches.Glider pics 005.jpg
Glider pics 008.jpg

The measurement of the height when one wing lays flat is much more difficult. As I have glued an additional chunk of balsa to weight down the front, it now rests uoon it, lifting the wings a bit more.
Glider pics 003.jpg
I did overlap the nose over the edge of the table, and then pressed the wing down almost level to the tabletop, and measured the height of the far wingtip. It came to 3.25 inches. Is this enough info?Glider pics 005.jpg
 
The total angle between the two wings comes to asin(3.25/6.75) = ~29*, or 14.5* of dihedral. This is a little low, but not so low that I wouldn't fly it first. As for the stalling, just keep adding nose weight (I use modeling clay) until it glides straight or does a very slight stall. Definitely color your glider with some sharpies though. Balsa is hard to pick up on grass.
 
The total angle between the two wings comes to asin(3.25/6.75) = ~29*, or 14.5* of dihedral. This is a little low, but not so low that I wouldn't fly it first. As for the stalling, just keep adding nose weight (I use modeling clay) until it glides straight or does a very slight stall. Definitely color your glider with some sharpies though. Balsa is hard to pick up on grass.

Oh, modeling clay! That's a good idea! How do you keep it in place when the rocket launches? Do you depend on it's own natural adhesion?
I suppose I could mold it on and around the "hook" without obstructing the release/hook. And perhaps the rounded molded shape might add to the aerodynamics a bit! Good call!

(I once helped my 8 year old build a plastic T-rex model (he refused to participate!) with airplane glue and assembled the 8 pieces together. As "we" finished the last part and attempted to make it stand, I realized I had skipped the step that required us to pack some modelling clay down the tail to weight it down. It was now sealed up, and just balanced on the feet, but far too tippy to survive. It didn't.)

So I know I've got some clay around this house....

Second, I was thinking about color as well...and while waiting for your response, I'm found a virgin roll of pinstriping in red left over from something else... so I started wacking off 8" stripes to run down the side of the rocket tube... and after the third one, got to thinking that I might want to wait on that...I'm adding weight to the tube before it has ever flown!

My daughter might like to use sharpies to color the glider. Guess that would not add any weight to it... She'd love that!

But if I find that the thing won't fly, or doesn't fly, due to the angle being too shallow, how do you recommend that I get the left wing (last one, lapped on top of the other) free? It's adhered by yellow glue at this point.SAM_0054.jpg
 
Took your suggestion, and turned my daughter loose with the markers. She choose the UNDERSIDE of the wings, after I added the red checkerboard stickers on the topside. (I'm impressed.)SAM_0055.jpg
 
That's pretty schnazzy lookin'! Quite the artist you have there.

I don't think that it "not flying" is a result of the dihedral, unless it is flipping over on you, which it shouldn't. I think the problem is mostly one of balance. I'll give you a basic rundown on trimming.

Pitch Trim
1.) Add enough nose weight that the glider balances at about 40% of the root chord back from the leading edge.
2.) Suspend the glider by the nose and tail and allow the wings to balance. Add clay to a wing tip such that the wings hang level.
3.) Give the glider a gentle, level hand toss straight ahead. If the glider stalls severely, add more nose weight. If the glider dives, remove nose weight.
4.) Repeat step 3 until the glider just barely stalls at the end of a hand toss.

Lateral Trim
1.) If you are right handed, trim for a left turn. If you are left handed trim for a right turn.
2.) Add a small amount of weight to the inside wing tip to initiate the turn.
3.) Give a harder throw, still straight ahead (not up) but with the wings banked 45* away from the intended glide turn. (Throw with a 45* right bank for a left-turning glider and visa-versa.)
4.) The glider should climb in a spiral, then at the top of the climb roll to the intended turn and begin a stable glide. Trim for about a 100' circle.

If you have too much trouble with lateral trim, just add a small (<1g) dob of clay to one tip an fly it on 1/2A6-2 motors to get the trim.

If you find that you can't get it to trim in pitch no matter what you do, lick your finger tips and "massage" the trailing edge of the elevator up a little. This will effectively give you "up elevator" and then start the trimming process over.

I hope I'm not giving you too much information. I'm trying to give you what you need to know without confusing/overwhelming you. If I am, just let me know/ask more questions.
 
Greatly appreciate the advice, Brian. I'll continue to work on trim and pitch over the next two days in the hopes of a successful launch this Saturday.

Finally found the "Scupty" clay polimer after quite a bit of searching. There's some left over/used to be drawn from, if I kneed and soften it tonight.
Not quite the modeling clay that I was looking for, but it will work, I believe! Now for a no-wind test glide or two...
 
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CRAP! After softening up the clay, I applied a chunk to the nose, and went outside for a test flight. A gentle toss made it float almost level, with a slight stall, then slip to the left and into the downspout...soft landing in the flower bed. I picked it up and faced the other direction to reconfirm. This time it immediately did a nose dive into the grass and snapped in two. There's a small knot hole in the boom right behind the main wings, and that's where it snapped. My guess is it was weakened by the first flight, and let go as I tried again. I'm rushing out the thick CA and the yellow wood glue to attempt a repair before tomorrow's launch. I might have to brace with some toothpicks or something else alongside the break. Do you have a recommendation of which to use? The boom cross section is about 1/8 by 1/8"...
SAM_0056.jpg
At least the fault showed up today, when I have time and resources to apply a repair....instead of out in the field or on the initial launch. (I'm beginning to think I may have bitten off more than I can chew with this delicate a unit. I'm thinking that DeeLite or CICI from Emonds Aerospace is looking better all the time!)
 
If you have some scrap balsa, I'd run some 1/16"x1/8" strip from ahead of the wing to about 1" past the break. Bevel the ends to a point before applying.
 
If you have some scrap balsa, I'd run some 1/16"x1/8" strip from ahead of the wing to about 1" past the break. Bevel the ends to a point before applying.

Yes, I believe I have some of the scrap from the flashing of the balsa that the boom came out of.

Do you recommend thick CA for the length of it, or yellow glue? I'm thinking Yellow glue may be stronger, but heavier. CA may be faster, but I'm not as experienced with it.
I'm gonna go carve out my brace and come back to check if you've replied before making a decision.
THANKS!
 
I personally recommend carpenter's glue as it's more forgiving, and much less brittle. If you can clamp it effectively I it's better. But If there's a good argument for the CA I'd like to hear it.
 
I personally recommend carpenter's glue as it's more forgiving, and much less brittle. If you can clamp it effectively I it's better. But If there's a good argument for the CA I'd like to hear it.

Thanks, Rich.
As the boom that snapped is 1/8 by 1/8", there's hardly any surface face for glue to "bite". So, I opted to spot CA there, and a small blob on the left and right sides as well... and now will attempt to glue a long "brace" along the bottom straight edge with Yellow wood glue and see if there's anyway to clamp or hold it in place overnight. At this point, it's become a salvage operation, having never launched yet, so I don't see much loss to try. I just wanted to 'jump the right way' if I have only one shot!

I carved off a nice, naturally long piece that was laser cut on both sides, except for a "natural bevel" on the front end and a short 1/2" cut at the reverse end to free it. I was very surprised at how easy it was to get such a brace, that is twice as thick as the boom that it's re-enforcing.
I applied a bead of yellow glue down the proper edge, and positioned it under the main wings, and it ends about an inch and a half behind the break. I kept looking for a "clamp", or a weight, or rubber band to hold this in place. I wasn't successful. After wiping the excess from the long joint, I realized there was the slightest of bows, either producing a sliver gap at the front, or, at the rear of the brace, depending on which end you held together with your fingers.

So, I gently rocked the joint until the brace came free again. The glue was getting tacky, but not fixed yet. I added a smaller bead of glue down the length, and then again pressed the brace into place, this time holding both the front and the rear pinched between my fingers.

It occurred to me that the best clamp was the fingers I was using. And since I didn't have anything else to do, I turned on the evening news, turned off the lights, made myself comfortable, and then...held on. I found after about ten minutes my fingers were tiring...and by fifteen, the crying of the family cat summoned me and I had to set it down. It was holding.

Solving the cat's problem (loneliness), I resumed the finger clamp,and felt the balsa was compressing. So I released the pressure, and found it was holding. Now I'm beginning to wonder if the thin balsa boom may be warping due to the humidity and the grain, since it's been so humid recently since I started the kit. Nothing to be done about that now.

So, the brace is on and curing, and we'll try trimming it again tomorrow.
 
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Yep, I've done that...used CA for tack - welding and held parts together by hand while carpenter's glue sets up a bit.

I have another trick I've used...i keep old paper towel and plastic wrap tubes around in case I need to fabricate custom jaws to hold an odd - shaped piece together in a bar or block clamp. Use some tape to stiffen/pad the jaws and you can provide just enough gentle clamping pressure to close any gaps. just like a real aircraft: you have to fabricate some tooling as well as the components.
 
Carpenter's glue is clearly the superior adhesive for the job. I limit my use of CA to repairs and high surface area joints.
 
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