Why Is NO ONE Designing BOOST GLIDERS & ROCKET GLIDERS For Maximum Performance ?

[Ez2cDave]

Why is NO ONE designing BOOST GLIDERS & ROCKET GLIDERS for Maximum Performance, anymore ?

Yes, all of the gliders from Dynasoar Rocketry and other companies are very cool looking, but they are NOT designed for maximum duration performance. I understand that RC is a big attraction, in that you have control, don't have to walk far ( usually ) to recovery them, and they are less likely to be lost.

One economic reason to consider high-performance gliders is that they are less expensive to build & fly and, being smaller, can fly on smaller, less expensive motors.

Competition can also make flying high-performance gliders a lot of fun . . . Compete against your friends, other clubs, and at formal competition events, if you like that sort of thing !

Yes, there are kits out there, but most of them are old designs from the "Golden Era of Rocketry" . . . Why not design and build some "modern" designs ?

"But, I don't know how . . ." There is only one way to overcome that . . . Learn new skills and techniques !

https://www.rocketryforum.com/threads/glider-design-trimming-library.155758

Dave F.

 

[Charles_McG]

NCR released their North Hawk in 2018.

 

[Ez2cDave]

NCR released their North Hawk in 2018.

Yes, Indeed . . . A great-looking RC kit !

My main point was maximum-performance free-flight designs, not RC or kits . . . Scratch-built designs.

Dave F.

 

[o1d_dude]

I was about to say because glider loss is fairly common without a dethermalizer set-up but I noticed that two of the photos show gliders with D/Ts. Primitive but still functional/better than nothing.

Hand launch and catapult gliders are a subject near and dear to me. Used to have a column in the National Free Flight Society’s monthly Digest. Discus style launch, large wingspan gliders are a big deal now. I was one of the first to campaign a 26” wingspan glider that took second place two years running in the Dawn Mass Launch at the US Free Flight Championships at Lost Hills. No thermals, just a glide for days...and I have a 79” wingspan (freakishly long arms).

 

[Ez2cDave]

I was about to say because glider loss is fairly common without a dethermalizer set-up but I noticed that two of the photos show gliders with D/Ts. Primitive but still functional/better than nothing.

Hand launch and catapult gliders are a subject near and dear to me. Used to have a column in the National Free Flight Society’s monthly Digest. Discus style launch, large wingspan gliders are a big deal now. I was one of the first to campaign a 26” wingspan glider that took second place two years running in the Dawn Mass Launch at the US Free Flight Championships at Lost Hills. No thermals, just a glide for days...and I have a 79” wingspan (freakishly long arms).

If you have any designs, techniques, or ideas, please feel free to post them here !

Dave F.

 

[Alan R]

If you have any designs, techniques, or ideas, please feel free to post them here !

I'm working on a rather unique one. Trying to engineer it right now. I'll let you know when I have something that flies.

 

[Ez2cDave]

I'm working on a rather unique one. Trying to engineer it right now. I'll let you know when I have something that flies.

Cool . . . Looking forward to seeing it !

Dave F.

 

[burkefj]

JH aerospace makes some neat kits and use interesting deployment mechanisms.

He's an indoor and free flight guy so is pretty up to speed on efficient design....https://jhaerospace.com/product-category/rocket-gliders/

 

[o1d_dude]

JH aerospace makes some neat kits and use interesting deployment mechanisms.

He's an indoor and free flight guy so is pretty up to speed on efficient design....https://jhaerospace.com/product-category/rocket-gliders/

Thanks for sharing the link.

I spotted something I like...D’OH! It’s going to cost me.

I don’t even like R/C but...old dudes can learn new tricks, too.

 

[Ez2cDave]

JH aerospace makes some neat kits and use interesting deployment mechanisms.

Joshua Finn does make some very nice gliders . . . I hope to see more from him, in the future. It would be great, if he posted in this thread.

Without sounding like a "broken record", my main intention is staying away from kits and talking about designing a glider, taking a few sheets of balsa wood,
sanding an airfoil by hand, building the model, trimming it, and launching it . . . All without commercial kits, plans, or copying the designs of others.

Yes, I admit that I'm "old school", having started in Rocketry in 1967 . . . No "die-cut" parts, "laser-cut parts", or "3D-printed parts" back then . . . There is a lot of personal satisfaction that comes from designing a model, building it, and flying it successfully.

Dave F.

 

[o1d_dude]

My earliest Estes order was for some body tubes to build a tubular fuselage for a Coupe d’Hiver model airplane. That class is known as F1G now that the FAI has taken the reins of international model aviation competition.

The rest of just call it “Coupe”.

 

[o1d_dude]

Joshua Finn does make some very nice gliders . . . I hope to see more from him, in the future. It would be great, if he posted in this thread.

Without sounding like a "broken record", my main intention is staying away from kits and talking about designing a glider, taking a few sheets of balsa wood,
sanding an airfoil by hand, building the model, trimming it, and launching it . . . All without commercial kits, plans, or copying the designs of others.

Yes, I admit that I'm "old school", having started in Rocketry in 1967 . . . No "die-cut" parts, "laser-cut parts", or "3D-printed parts" back then . . . There is a lot of personal satisfaction that comes from designing a model, building it, and flying it successfully.

Dave F.

Back in the day, I designed two different Catapult launched gliders that were “published”.

Not that big a deal as I was the “Tao of Hand Launch Glider” (HLG) columnist for the monthly(?) Digest of the National Free Flight Society at the time. Of course, I selected my two gliders.

Both gliders were launched using an 9” stick and a 9” loop of rubber. The first one “Crowbar” was very popular but I felt it was a good first effort and followed up with the “RPG”. I scaled it up to a 26” wingspan and competed with it for a few years. Large wingspan gliders seemed to catch on and eventually morphed into the discus launch style where even larger wingspans and mucho carbon fiber was used.

Historical Note: The name “Crowbar” came from a club member who once described the model of another competitor as having the glide of a crowbar.

Historical Note 2: I lost every one of those damn things in thermals even after the de-thermalizer popped the wing off.

Historical Note 3: When last I attended one the local contests, a small flying club of young kids and their mentor who were flying my design came up to chat.

Glory is fleeting, enjoy it while you can.

 

[Rocketjunkie]

There are NAR glider contests. I'm not into competition rocketry but I bet there's a lot of innovation going on. How much they will release may be an exercise in futility (where's that :duck: smiley)

 

[Ez2cDave]

There are NAR glider contests. I'm not into competition rocketry but I bet there's a lot of innovation going on. How much they will release may be an exercise in futility (where's that :duck: smiley)

NAR Competitors, nowadays, typically fly kits or build gliders from 40-50 year old plans . . . Very few "new" gliders are being designed.

HOWEVER, the "BTC's" ( Big Time Competitors ), where ever possible, build custom vacuum-bagged foam/fiberglass models, incorporating, carbon fiber also. Naturally, their gliders also use ultra-micro RC systems. Typically, a C-powered RCRG can post flights of 30 minutes or more, in the hands of a skilled pilot.

As one can easily see, a "free-flight" model has ZERO chance of winning, under those circumstances . . . Things "equalize around "A" impulse and lower, due to the increased mass, if using RC. Since RC gear used to be much bulkier and heavier, lighter & smaller systems are now dominating the lower impulse classes.

You can see the advantage very clearly here : https://www.nar.org/contest-flying/records/

Dave F.

 

[fulldec]

And yet the guy who won C-division C RG last NARAM won with a free flyer design (over at least 2 RC models). Not only that, it was the multi-round version of the event where you fly 3 times but you are only allowed 2 models. This make getting at least one back almost mandatory. So I guess "no chance" is not quite accurate.

 

[Ez2cDave]

And yet the guy who won C-division C RG last NARAM won with a free flyer design (over at least 2 RC models). Not only that, it was the multi-round version of the event where you fly 3 times but you are only allowed 2 models. This make getting at least one back almost mandatory. So I guess "no chance" is not quite accurate.

Multi-Round is not a "maximum duration" event. There are "Maxes", beyond which, any additional duration does not count towards a Competitors score. In "C" impulse, the "Max" is 240 seconds / 4 minutes.

In a non-Multi-Round event, there is, of course, no "Max" involved . . .

From NARAM-50 ( 2008 ), where Chad Ring flew his RC glider in the first picture, these are his times, versus the competition. This was D-RG ( Rocket Glide ) maximum duration, with no "max" cut-off.

His 1st flight was 1267 Seconds ( 21 minutes, 7 Seconds ) . . . His 2nd flight was 1328 Seconds ( 22 minutes, 8 Seconds ) . . . Bear in mind that this was 12 years ago and the "technology has not moved backwards".

The main advantage to RC is the ability to "hunt" for thermals and to be able to fly up-wind, to keep the glider in sight of the Timers. Free-flight models do not possess those abilities.



Dave F.

 

[o1d_dude]

Quite right, Dave.

The acronym “OOS” stands for “Out Of Sight”. There are also rules for determining when a model is officially OOS at which time the stopwatch is stopped.

If a timer can no longer see the model, they count out 10 seconds. If the model is still no longer visible the watch is stopped and the 10 seconds are subtracted from the watch reading. If during the 10 second countdown the model becomes visible again, the watch is not stopped and the flight continues to be timed.

Many models are trimmed out with reflective tape (Sky Sheen, etc.) to make a flash at certain positions relative to the sun. This is particularly helpful for the flyoff rounds which often run into the twilight. Contrasting color schemes (light/dark) are helpful during the day.

My rockets are always painted GLOSSY fluoro pink and metallic black which both flashes and shows contrast. Obviously a holdover from my AMA Free Flight days.

 

[mcderek]

Most FAI Free flight planes carry LED flashers to help with visibility in evening flyoffs. My picture is of me launching a coupe several years ago.

 

[Rktman]

Inquiring minds want to know. Subscribed!

 

[o1d_dude]

Most FAI Free flight planes carry LED flashers to help with visibility in evening flyoffs. My picture is of me launching a coupe several years ago.

That's a new but not unexpected development.

I've been out of the hobby for 20+ years now.

Assume digital timers are now de rigeur as well (motor run, transition trim, D/T) and GPS locators. Jim Walston was way ahead of the game back in the day.

 

[mcderek]

That's a new but not unexpected development.

I've been out of the hobby for 20+ years now.

Assume digital timers are now de rigeur as well (motor run, transition trim, D/T) and GPS locators. Jim Walston was way ahead of the game back in the day.

In the World Championship classes (F1A-C) electronic everything is the way to go. The new electronic timer packages are amazing. Pretty much what's available in HP rocketry at a fraction of the weight. I timed Alex Andruikov at a Lost Hills contest in the 7 minute flyoff. He used a red LED flasher that flashed twice, then paused. Incredibly easy to follow in the evening light. There were several other planes with single red constant flashers.

 

[o1d_dude]

Alex is still one of those fliers who always seems to be a step ahead of everyone else.

Good on him.

 

[Ez2cDave]

In the World Championship classes (F1A-C) electronic everything is the way to go. The new electronic timer packages are amazing. Pretty much what's available in HP rocketry at a fraction of the weight. I timed Alex Andruikov at a Lost Hills contest in the 7 minute flyoff. He used a red LED flasher that flashed twice, then paused. Incredibly easy to follow in the evening light. There were several other planes with single red constant flashers.

Derek,

Where are those typically mounted on the airframe ?

Dave F.

 

[mcderek]

Derek,

Where are those typically mounted on the airframe ?

Dave F.

Usually on the fuselage bottom at the CG location.

Here is the FF Electronics unit_

 

[Maxout]

An interesting thread. I'm going to say from the start I've always designed "BOOST GLIDERS & ROCKET GLIDERS For Maximum Performance".

I'm pretty sure I have the only R/C boost glider design ever kitted that can be launched safely on 1/2A motors. It in fact gets more than high enough to catch thermals. On 13mm A motors, the flight times are nearly 2 minutes in dead air even with minor compromises we made for reliable laser cutting.

If you're looking for scratch building, it's out there, not going away. My original switchblade gliders remain some of the best dead air performers ever in RG classes. I was getting consistent 50 second flights off a piston with Estes 1/4A motors. The 1/8A version does 70 seconds reliably in dead air. I don't understand why people are scared of swing wings. They're a million times better than slide wings.

 

[Ez2cDave]

An interesting thread. I'm going to say from the start I've always designed "BOOST GLIDERS & ROCKET GLIDERS For Maximum Performance".

I'm pretty sure I have the only R/C boost glider design ever kitted that can be launched safely on 1/2A motors. It in fact gets more than high enough to catch thermals. On 13mm A motors, the flight times are nearly 2 minutes in dead air even with minor compromises we made for reliable laser cutting.

If you're looking for scratch building, it's out there, not going away. My original switchblade gliders remain some of the best dead air performers ever in RG classes. I was getting consistent 50 second flights off a piston with Estes 1/4A motors. The 1/8A version does 70 seconds reliably in dead air. I don't understand why people are scared of swing wings. They're a million times better than slide wings.

Please post up some pics of your gliders !

Personally, I like "Scissor-Flop" designs for RG's . . . I think many people, including myself, steer away from Swing-Wings because of the tendency of having high aspect ratio wings not "swing into position" reliably, unless the glider is almost "dead still" in the air, at deployment. The problem comes from the long wing having to open against "wind resistance", if the glider is moving, particularly if the Boost is non-vertical.

On the subject of "Micro-RC", is there a way to drastically "slow down" the Servo travel rate ? The ones I have seen seem to almost "slam" from one extreme to the other, making for a very "Herky-Jerky" flight, rather than allowing smooth, slow control inputs.

Thanks,

Dave F.

 

[Maxout]

Dave,

I'm on the road at the moment so can't take the photos you really want to see.

Swing wings can deploy at any virtually any airspeed if designed right and tensioned correctly. Those that don't have a design flaw and should be redesigned to make it go away. Not trying to throw old designers away since that's all most of them knew in the 1970s, but this is 50 years later and we have better ways to do things. If an F1C can deploy a 2.5m span swing wing at over 100 mph, I think we can get a little bitty balsa thing to deploy at lower speeds.

If your servo movements are herky Jerry, program so expo on your transmitter and/or spend more time on the flight sim learning really smooth control inputs. Better yet, buy an F3K glider and spend about 20 hours flying it at the edge of visibility in thermals. You'll learn really smooth control then. What you absolutely do not ever want are servos that are slow to respond to your inputs. There will come a time when you need that elevator at full up deflection (or full down) right NOW, and if it doesn't, you'll be really angry at yourself for programming it to slow down (and to answer your question, FrSky radios do allow you do that, and even sing a song to you while they do it if you like, but they don't make coffee yet).

 

[BABAR]

I timed Alex Andruikov at a Lost Hills contest in the 7 minute flyoff.

Anybody consider that “Lost Hills” might not be the best name for the location of a model rocket duration competition?

 

[Yukon@K-9 Rocket Tech]

I totally agree with you, which is why I want to build one based off the Tomohawk Missile, which would be so dope!

 

[milehigh]

Thanks for using my photo of the FlatCat in the original post! It's always been my favorite glider design.
I had 3 of them back in the old fleet days. The one in the photo was built in 2019 to replace a glider that I lost on its maiden flight in 2018. That FlatCat thermaled away on a B4-2 flight. It was in sight for over five minutes before I lost it, and hadn't shown any significant glide altitude loss!