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Sep 13, 2021, 11:53 AM
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burkefj's Avatar
Dynasoar Rocketry Valkyrie R/C rocket glider flights (2 min 21 sec)
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Sep 13, 2021, 11:57 AM
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burkefj's Avatar
Some trim flights on my new mini Avro Arrow for 18mm motors

Dynasoar Rocketry Avro Arrow R/C rocket glider flights (4 min 25 sec)
Sep 14, 2021, 05:46 AM
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Quote:
Originally Posted by burkefj
I was wondering if you had it on for pitch as well, yes that would help, it would be more noticable in wind as well as you can over-correct when pitch sensitive...


QUOTE=sr205347d;47804611]Maybe the gyro helped with that.
[/QUOTE]

Frank,

If the use of a gyro in pitch allows the CG to be further aft, then the elevons will not be deflected up as much in trimmed gliding flight. This will increase the lift coefficient, and reduce trim drag. As a result, the glide duration, or maneuverability, will be improved.

Try it out.

Andy
Sep 14, 2021, 12:32 PM
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X30PILOT's Avatar
I used an Eagletree Guardian in my X-2 in the roll axis only.
In the 3D mode it is very much like the AS3X, in 2D mode it works like SAFE.
This was tested and tuned in a small profile test model first powered with an electric motor and then rocket power prior to installing it in the big X-2.
It worked great. If I lost sight of the X-2 after boost, I could activate the glide trim and hit the 2D mode and the X-2 would have landed its self somewhere in the Black Rock Desert.
While a gyro works good in pitch during boost, a properly trimmed glider will seek its own pitch attitude.
Being a glide is not necessarily a level pitch, the gyro can override a good glide and could even slow the glider to a stall.
Perhaps the optimum would be to have the pitch mode on for boost and have it disabled once the glide trim is applied.

Dave
Sep 14, 2021, 01:20 PM
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Quote:
Originally Posted by X30PILOT
I used an Eagletree Guardian in my X-2 in the roll axis only.
In the 3D mode it is very much like the AS3X, in 2D mode it works like SAFE.
This was tested and tuned in a small profile test model first powered with an electric motor and then rocket power prior to installing it in the big X-2.
It worked great. If I lost sight of the X-2 after boost, I could activate the glide trim and hit the 2D mode and the X-2 would have landed its self somewhere in the Black Rock Desert.
While a gyro works good in pitch during boost, a properly trimmed glider will seek its own pitch attitude.
Being a glide is not necessarily a level pitch, the gyro can override a good glide and could even slow the glider to a stall.
Perhaps the optimum would be to have the pitch mode on for boost and have it disabled once the glide trim is applied.

Dave
Dave,

I have never used the AS3X, so I can't comment on it. I have used the Eagle Tree Guardian in other RC airplanes, but only in the "Direct Rate 3D Submode" where it dampens the roll/pitch/yaw rates with no reference to level flight.

In this application, I am using an Admiral RX600SP receiver, but not in what they call the "Recovery" mode. So, like the ET Guardian in 3D, there is only rate damping and no reference to level flight. You can use it to dampen any "pitchy" issues in boost and it will not effect whatever glide speed you want to trim it to, as long as you do not use "Recovery" mode. So there is no need to turn it off after boost.

Andy
Sep 22, 2021, 10:22 PM
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burkefj's Avatar
A little experiment today...

1/21 scale R/C X-15 Rocket glider flying on composite E motor (6 min 5 sec)
Sep 23, 2021, 02:14 PM
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Thomas B's Avatar
Quote:
Originally Posted by burkefj
A little experiment today...

https://youtu.be/hbWb4GULO8w
Might be a good candidate for water ballast release to correct the CG for a better glide and an SAFE RX for some pilot backup at altitude.

It might end up flying at a lower net weight than it does on the 18mm motor.
Latest blog entry: My 2021 event schedule
Sep 23, 2021, 04:20 PM
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burkefj's Avatar
It won't be lighter, the 24mm casing and liner/nozzle weigh 32 grams compared to 20 grams for the 18mm, so you have an added 20 total grams delta of additional nose/tail weight to the model in any case irrespective of the propellent compared to the stock 18mm model. It's an additional 20 grams of propellent thats burning, so about 18 grams additional nose weight to drop which seems pretty small to warrant the complexity of some sort of bladder. The size of the model is just so short the 18 grams makes a difference in the cg shift.

I made up an adapter for 18mm which only weighs 3 grams, and the 18 grams nose weight for the 24mm motor is held in with velcro so I can remove it and fly it on the D-13/D-24 at only about 5 grams penalty compared to a stock 18mm kit.

I mean I can fly it, I just don't think it's generically easy enough to fly to sell as a general kit. I want people to easily be able to have success with my kits. I'm sure you and Dave could fly it as well, you get about 50 seconds of glide time at the higher boost compared to about 25-30 with the 18mm motors. Still short but hey, it's an X-15...

I'm doing the best I can with simple designs and available parts. What really needs to be done is a pure built up 6mm/3mm 4" based X-15 with skin which would come in at about the same 9 ounces rtf but be large enough that you have half the wing loading and cg shift. But I'm too lazy to do it.

I can't do pop pods due to where I fly and recovery problems, that might work but would require a redesign and additional structure to support the wing with a center tube.


Quote:
Originally Posted by Thomas B
Might be a good candidate for water ballast release to correct the CG for a better glide and an SAFE RX for some pilot backup at altitude.

It might end up flying at a lower net weight than it does on the 18mm motor.
Last edited by burkefj; Sep 23, 2021 at 04:25 PM.
Sep 23, 2021, 05:48 PM
Electric Coolhunter
Thomas B's Avatar
I should have done the math….

I have been thinking about a water ballast exit tube from the base of the nose cone. Rig up a slightly loose fitting plug on the rail, a little to one side to clear the buttons so that it engages the tube via gravity. The key to making it workable would be some sort of soft rubber seal that would compress enough from the weight of the model to prevent leakage while on the pad.

Don’t want to have a friction fit plug that might accidently defeat the E6 and leave the model on the pad.

One downside is that the body tubes would need to be fairly waterproof…..sigh.
Latest blog entry: My 2021 event schedule
Sep 23, 2021, 11:10 PM
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burkefj's Avatar
George Gassaway had a system in his X-1 that worked well, until it didn't

Quote:
Originally Posted by Thomas B
I should have done the math….

I have been thinking about a water ballast exit tube from the base of the nose cone. Rig up a slightly loose fitting plug on the rail, a little to one side to clear the buttons so that it engages the tube via gravity. The key to making it workable would be some sort of soft rubber seal that would compress enough from the weight of the model to prevent leakage while on the pad.

Don’t want to have a friction fit plug that might accidently defeat the E6 and leave the model on the pad.

One downside is that the body tubes would need to be fairly waterproof…..sigh.
Sep 24, 2021, 12:59 PM
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X30PILOT's Avatar
Frank,

That’s some interesting experiments you’re doing with the X-15, and a good discussion on increasing its boost.
I’ve got to add that I find the performance with the stock setup using the AeroTech White Lightning 18mm motors very satisfying.

Dave
Sep 24, 2021, 03:20 PM
Electric Coolhunter
Thomas B's Avatar
Quote:
Originally Posted by burkefj
George Gassaway had a system in his X-1 that worked well, until it didn't
He was using motors with more grunt off the pad than an E6. Evidently enough to unplug a drain tube than needed a little pull to unplug.

Even if the drain failed, you would only be slightly worse off than we are now on your models.

Might be interesting to compare glide times from a set altitude with a nose heavy for glide model with the same model balanced to a more optimum CG. Probably not a huge difference, but would be an interesting test.
Latest blog entry: My 2021 event schedule
Sep 24, 2021, 04:42 PM
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burkefj's Avatar
Thanks Dave I thought long and hard about it and guessed that the 18 mm in this size would probably be pretty optimal, I've only flown it on the d 24s mostly because the nozzle is bigger and easy to insert those little igniters and blue thunder lights really easily but I did order some d13s which actually I think have about a Newton second and a half more impulse so I'm excited to try that. I did make up an 18 to 24 adapter and it only added 3 g so I can fly this model on the 18 mm motors as my extra nose weight is held in by Velcro so I can remove it when I'm flying the lighter motors.

Quote:
Originally Posted by X30PILOT
Frank,

That’s some interesting experiments you’re doing with the X-15, and a good discussion on increasing its boost.
I’ve got to add that I find the performance with the stock setup using the AeroTech White Lightning 18mm motors very satisfying.

Dave
Sep 24, 2021, 04:44 PM
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burkefj's Avatar
Yes that would be interesting to try a test if I had another flyer with an RC plane that could take the model up to a set altitude and release it I could do exactly what you're suggesting. I think in the end with these flat plate airfoils and a minute to a minute and a half of glide time, you're probably only talking 10 or 15 seconds improvement.

Quote:
Originally Posted by Thomas B
He was using motors with more grunt off the pad than an E6. Evidently enough to unplug a drain tube than needed a little pull to unplug.

Even if the drain failed, you would only be slightly worse off than we are now on your models.

Might be interesting to compare glide times from a set altitude with a nose heavy for glide model with the same model balanced to a more optimum CG. Probably not a huge difference, but would be an interesting test.
Sep 27, 2021, 11:04 AM
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burkefj's Avatar
A montage from todays flights at Sheridan Oregon, D and E powered R/C rocket gliders
R/C rocket glider montage September 2021 D and E powered (13 min 22 sec)


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