Radical Rocketry P-38
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So, where does the rocket motor go?
Right behind the cockpit, one motor slightly canted down just enough to not burn off the tail.
Crazy airplane rockets rule! Fun kits for all the old dudes! Just look at what the big kidz are flying these days!
Looks great and swing test looked good.
How much nose weight did you use?
I used 2oz and I think I tried to get my CG a bit closer to front of the wings but that may have been conservative.
Did you try a swing test with the propellers on? just curious...
How much nose weight did you use?
I used 2oz and I think I tried to get my CG a bit closer to front of the wings but that may have been conservative.
Did you try a swing test with the propellers on? just curious...
None.
I did the swing test twice. First time with a spent motor and no parachute and was surprised to see how stable it was. So I redid it with a new motor and the parachute which just barely fits inside. Going to have to use nomex. No room for wadding. And that was also stable. I'm thinking about trying a glide test, no shoot, no motor, but I don't have any place soft for it to land yet.
Very cool -- would love to see if you can get it to glide recover. The motor will eject itself if you do not wrap with tape (at least that happened to me once when I neglected to tape it).
This is my first traction motor setup so I was conservative with weight. It did a fair amount more swooping with less weight so it might be safer to use at least 1oz of weight or something. Totally your call though!
I used a small chute --15" If I remember correctly, and only attached to the NC with the weight in it. It is definitely tight fitting the chute in there. I folded mine up pretty tight - Maybe 5-6 folds to get it to fit in 1.5 to 2" or so and then put wadding / dog barf in behind it (maybe some wadding wrapped around chute since it is a small airframe).
uff.... hard landing... I assume that was not just with a hand toss. Was it stable in the flight without nose weight?Result of glide test. After repairs, parachute.
In my tests it was close to gliding without the nosecone (or at least it fell flat).
If you do not need to add much nose weight you could maybe bring the nosecone down with a small chute or maybe even a streamer and let the body glide / tumble recover.
Not very stable and just a hand toss. Rolled once. Put about an ounce of nose weight. Started ok then said ok look, ground. I wonder if it will be friends with me and dropped hard.
Ah - sorry it did not work out (I was hopeful that I had just been too conservative). Good experiment and good repair I suppose!
I guess I'd go with pushing CG to front of the wings and stick a chute in there for the heavy NC.
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The cruel world of warbird oddrocs. Maybe some day eject the heavy nose, push forward a piston to make a glidable CG and glidable aerodynamics.
Very poor flight performance. Failed to record video but it pitched over once clear of the launch rod and corkscrewed until power ran out. No damage though.
How much nose weight did you put? I usually used 2oz but may even go up to 2.5oz in the latest build.
Only one ounce. Will increase to 2.5 for next attempt.
Sorry about instability but glad there was no damage...
Gosh darn airplane rockets. So much stinking nose weight!
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This is a deep Jedi trick for glider nose weight that may work on some but not all gliders.
Goal is rear ejectable nose weight with retained cone staying in place with glider.
Required
Hollow plastic cone, glued in and strong enough to deflect an ejection blast. Internal JB weld or equivalent coating also needed .
Rear eject pod. Forward and aft sliding centering rings (glued to motor mount, slide out the back of the body.)
Cut the base off the plastic nose cone so internal space is open to main tube. You’re gonna need that space. Glue it in (strong external tape wrap with vinyl tape is functionally acceptable if you want to access internals later, or repurpose the cone for another project,)
Extend the motor tube forward of the forward centering ring so it actually touches the inside of the cone. If you have a narrow triangular cone (narrower if pointier than a Bertha), downsize your forward tube extension, you want SPACE around that tube INSIDE the cone.
Wrap your clay or ideally shaped lead or tungsten or even shaped epoxied bunch of BBs around the outside of the extension of motor mount inside the cone. This MUST still fit easily INSIDE the cone with the pod fully inserted,
The chute fits between the centering rings, folded not rolled. If space between tubes is inadequate, Jedi tactic #2 is employed. Downsize the tube just forward of the motor mount, say BT50 to BT20, or BT20 to BT5, line INSIDE with rolled aluminum can piece as otherwise concentrated narrow ejection charge WILL burn through tube just forward of motor mount. Jedi tactic #2 can be employed on any rear eject rocket and dramatically increases your available laundry space. Ejectable pods MUST SLIDE EASILY. They are finicky and will grab and fail to eject if packed tightly. @lakeroadster has a nice packing technique.
Result; you can load a good amount “nose cone “ weight on the forward end of the pod. When loaded, this weight IS technically inside the cone and more importantly on boost effectively pulls the CG far forward.
At ejection dumps nose weight (shifts CG) AND dumps motor casing (lightens the glide further).
Works best on long fuselage gliders, need some length for chute, can be done with streamer, but a chunk of lead on the end of a streamer may not slow down enough to be safe.
Goal is rear ejectable nose weight with retained cone staying in place with glider.
Required
Hollow plastic cone, glued in and strong enough to deflect an ejection blast. Internal JB weld or equivalent coating also needed .
Rear eject pod. Forward and aft sliding centering rings (glued to motor mount, slide out the back of the body.)
Cut the base off the plastic nose cone so internal space is open to main tube. You’re gonna need that space. Glue it in (strong external tape wrap with vinyl tape is functionally acceptable if you want to access internals later, or repurpose the cone for another project,)
Extend the motor tube forward of the forward centering ring so it actually touches the inside of the cone. If you have a narrow triangular cone (narrower if pointier than a Bertha), downsize your forward tube extension, you want SPACE around that tube INSIDE the cone.
Wrap your clay or ideally shaped lead or tungsten or even shaped epoxied bunch of BBs around the outside of the extension of motor mount inside the cone. This MUST still fit easily INSIDE the cone with the pod fully inserted,
The chute fits between the centering rings, folded not rolled. If space between tubes is inadequate, Jedi tactic #2 is employed. Downsize the tube just forward of the motor mount, say BT50 to BT20, or BT20 to BT5, line INSIDE with rolled aluminum can piece as otherwise concentrated narrow ejection charge WILL burn through tube just forward of motor mount. Jedi tactic #2 can be employed on any rear eject rocket and dramatically increases your available laundry space. Ejectable pods MUST SLIDE EASILY. They are finicky and will grab and fail to eject if packed tightly. @lakeroadster has a nice packing technique.
Result; you can load a good amount “nose cone “ weight on the forward end of the pod. When loaded, this weight IS technically inside the cone and more importantly on boost effectively pulls the CG far forward.
At ejection dumps nose weight (shifts CG) AND dumps motor casing (lightens the glide further).
Works best on long fuselage gliders, need some length for chute, can be done with streamer, but a chunk of lead on the end of a streamer may not slow down enough to be safe.
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BTW, since you are a scale model guy the above would work to make a great SR-71 glider. See the Apogee Dark Bird or on the forum the SR-73 Raven. Add your 3D stuff and would make a nice glider.
Glad you had a good flight today - sorry about the lost nosecone!
ReynoldsSlumber
Well-Known Member
Had similar thoughts about turning the Apogee X-15 into a boost glider.
The old Estes "Crusader Swing-Wing" used a similar method, though instead of nose weight, ejection of the internal pod of course triggered a swing wing mechanism. Also the pod carried the bottom fin with it, so that the airplane portion was left with a V-tail, and the belly was unobstructed for landing. Not that it ever landed all that gracefully...
