Boost Glider Argent -Space Ferry experiment

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SteveNeill

SNG Studio Ventura
Joined
Aug 17, 2019
Messages
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Location
Ventura CA
Yesterday I was in my local hobby shop picking up some engines and looking at kits. The owner is a friend and knows what I like and he offered me a Argent and a Ventris for 70 bucks. I already have a built Argent but thought maybe I could do something with it I've been thinking about.

I'm planning to use the nose cone and transition point into a glider Space Ferry. Add some small RC gear and test this all out before I scratch build the Von Braun Space Ferry I am planning.

I put the Argent into Openrocket and got going. Stability was all over the map at first. I had to increase the fins size and shape. I tried different wing shapes until I hit the delta wings and things began to improve. Even with a G 25 motor I was getting good results in the simulations if I can trust them.

I'm just beginning but frame up starts tomorrow. I'll be using Depron for the ferry structure mostly. Micro RC gear(I have a bunch).the kits.jpg
SNG Space Ferry.jpg
 
I would think that Frank would have something to say. To me I am surprised that this model is stable. I would think that some ballast would be needed towards the front end of the first stage. Perhaps, the electronics and battery in the glider are enough ballast. This reminds me of the Estes Sidewinder kit and I assume that model is stable. The other concern would be how fast does this model go. I don't think that depron cannot handle high speeds. Frank would know more about that.
 
The sim says 158 mph. And I had had Depron airplanes and other foam planes survive that speed. However they weren't boosted by a rocket engine. The large fins are what did the most to stabilize the rocket. These sims were ran on a G 25 6 s and then I switched to a G53 FJ-7 which tamed things a bit and brought down the apogee to 750 ft. I could still go lower because at 750 st and 22 inch glider will still be hard to see.
It's worth a try. The flights and materials are not so expensive. ;)
 
That's a pretty tiny glider for 750 feet altitude. you can control the model on boost that's what I did with my Titan stack do you have to reverse the elavon direction underboost and then switch them to normal operation once the glider comes off, due to the fact they'll act like canards but that does give you some capability to correct if it really pitches hard. Id rely on a little more balast and keep the boost speed lower I like to keep my model boostspeed about 88 feet per second or so.
 
Thank you for your advise you have the experience with these types of projects. I was thinking the same thing.Keep the boost speed lower. I could put the switch back to elevons on my DX6 Spektrum radio. Just got a new one and the capability is there. The fact it talks helps to so I don't have to look down at the TX. BTW could I have a name? Thank you very much for your input.
 
Glider look like a flying brick so far. I need to run some tests on wing area overall. Lucky for me I have a nearby slope where I fly sailplanesIMG-1477.JPG to test and get things dialed in. Just a frame up for looks so far.
 
A lot more wing by increasing the root. Increasing span made the rig less stable. This brick should fly better.

bigger wing.jpg
 
Got the plywood fins made and installed with epoxy. Filets in. Booster is basically done. Test glided the Ferry today. It flies to my surprise. Got the CG dialed in. Will still increase wing area a bit more. Tomorrow I start installing the electronics and radio gear. So far so good.

IMG-1490.JPG IMG-1490.JPG IMG-1488.JPG IMG-1496.JPG IMG-1485.JPG IMG-1484.JPG
 
So as long as the electronics are installed so the CG remains in place, you're confident it will glide the same?
 
Yes I am. This Spectrum brick and bat weights little at all. I was going to use two HS 55s but they are too big for this 23 inch long glider and I plan to run to control rods out from underneath where there will be an equipment bay access hatch.

I increased the wing area a bit more at the cost of some stability. I'm down to about 1.5 now but with the elevons I should have a certain amount of pitch control to compensate. I may need to increase the size of the elevons.

This bigger wing glides pretty well now. I get and actual glide and belly flop.

I'm hopeful. Baby steps.

PS Frank inspired me to add the dihedral. I noticed the first time I was tossing it it had a tendency to oscillate side to side or wobble that has since stopped.

IMG-1515.JPG IMG-1510.JPG
 
Very nice. I love seeing the work of folks that really know what they're doing

Gliders are magic to me, I can just about handle the Astron skydart, and I'm pretty sure that was by pure luck.
 
I increased the wing area a bit more at the cost of some stability. I'm down to about 1.5 now but with the elevons I should have a certain amount of pitch control to compensate. I may need to increase the size of the elevons.
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Not sure how you are linking up the booster and the glider, there is a trick you can use to improve stability on boost without increasing GLIDER weight. If you can extend your booster tube further up inside the glider (may be challenging with the electronics) you can put some weight on the forward end of the booster tube, effectively putting it INSIDE the glider body during boost so moves the CG forward, but all the mass is ejected from the glider (or vice versa) at separation. It works especially great with internal pop pod gliders, e.g. Apogee DarkBird clones.

Looking forward to a good flight report!
 
I got the wings installed. Added some balsa LE's. Add the radio gear. It is set for elevons. The booster is finished for now.

I took it out on the front lawn of the building again for some tossing into the wind. Got a lot of weird looks from my neighbors. They should be used to it by now I took a EDF jet off the street more than once and they stood in disbelief but I digress.

It actually glides now and responds to control. Pitch and roll I have. Next up is to take it to the dunes and launch and see how it glides from higher up. GC seems right. It took a lot of tossing to get it right. Deltas are pretty forgiving even when tail heavy, not so good nose heavy.

I'm considering turning a foam nose on my lathe it would make the plane considerably lighter. I think.IMG-1520.JPG IMG-1526.JPG IMG-1527.JPG
 
The QCC looks so small in that picture.

Also, I'm really digging the Zephyr. Not generally a fan of the artwork and paint scheme in Apogee's kits, but they nailed that one.

Oh yeah and the glider looks good. Where does the CP come out on that whole stack?
Neil it is currently located as per Open Rocket. and yes they did nail it. Love the rocket.
bigger wing.jpg
 
Not sure how you are linking up the booster and the glider, there is a trick you can use to improve stability on boost without increasing GLIDER weight. If you can extend your booster tube further up inside the glider (may be challenging with the electronics) you can put some weight on the forward end of the booster tube, effectively putting it INSIDE the glider body during boost so moves the CG forward, but all the mass is ejected from the glider (or vice versa) at separation. It works especially great with internal pop pod gliders, e.g. Apogee DarkBird clones.

Looking forward to a good flight report!

thanks BARAR I am too. ;) Thanks for the input. As it is the transition blows away from the booster and that kicks the glider away followed by the cute if all goes according to plan.
 
That looks good. I'm surprised it's as far back as it is, with those monster wings up front. Love the simple but effective paint scheme as well.
 
Thank you gentlemen. And I'll take a look at those "vays". ;)
The booster fins are much larger than the wings and they are 3/16 model ply. So it has that aft balast Frank recommended.
 
Yes but what I want to be able to do is add strap on boosters as I have seen you do. Something about developers version or something like. I saw the Exposition. Love that one. Must make bigger version one day. I'm using Lightwave to do a design currently.
 
I didnt tecommend aft balast....make sure to look up how to reverse your elevons via switch, i had to do two identical mixes to get full throw...remember they need to go opposite for pitch on boost or it will be a short flight...

You have to mix elevator to elevator with a negative 100% and map it to a switch position, i had to do two identical mixes to actually get full movement.
 
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Got it Frank. I am not 100% positive that this new radio of mine will do that. Will look into it. I have a lot of Elevons on this since I worked out the radio throws and centering of the servos. It's ready to try although I plan to test it at the dunes down the street from me. Toss and glide. Booster looks good. Solid and ready to fly.IMG-1533.JPG IMG-1534.JPG
 
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