Opinions solicited regarding proposal for Horizontal Spin Recovery Duration as a NAR competition event

[BABAR]

Okaaaaay, here's my proposed submission to National Association of Rocketry to make this a competition category. Feedback welcome. @Dotini , this is basically your ballpark, so if you want to quash it that's okay with me. I have to get this in by September 1, 2023 to get it considered for the next cycle. I do think DURATION is a better category than Altitude. It simplifies things as altimeters are not needed, and I think the real challenge is achieving long hang time.

Basically I just used the Parachute Duration rules as a template, changed the numbers, and changed material to cover Horizontal Spin Recovery.

I am posting this in both the Scratch Section and the Contest Section.

Brief Summary of the Proposed Change:
New Competition Category: Horizontal Spin Recovery Duration

State Logic and Intent of Change:
Something relatively new and fun to interest current members and possibly entice new members.

Effect, if any, on current competition and NAR records:
None.

Exact wording for the rule revision as it should appear (include section#):

41 (next unused number under Duration) Horizontal Spin Recovery Duration

41.2 Scope
Horizontal Spin Recovery (HSR) comprises seven events open to single-stage entries using rockets with no moving parts. The rocket uses a fin configuration that functions under Barrowman equations for boost stability, uses the ejection charge vented through one or more ports to redirect the rocket from stable boost near zero angle of attack, to significantly off-zero angle of attack. Once well off zero angle of attack, the applicable stability equation of Barrowman doesn't apply and Center of Lateral Area (aka Cardboard Cut-Out) rules apply. Falling off vertical axis induces rotation of the rocket around its long axis as the rocket falls. The induced spin causes the rocket to orient perpencular to the fall vector (parallel to the horizon, i.e., Horizontal, hence the name.) This is a positive feedback mechanism, as the rocket becomes gradually more horizontal, the spin effect is amplified and the rocket becomes even more horizontal. Eventually the rocket achieves a perfect horizontal position. This causes the rocket to fall in the orientation of maximum drag.
The purpose of this competition is to achieve the longest flight duration time.

41.2 Qualification
With the exception of the burned motor contents and blown clay cap, the rocket must remain in one piece with no structural change of any kind. This includes no device or machination to change the center of gravity aside from the motor contents above. The rocket must be returned for inspection in one piece with no damage and capable of repeating a flight with only replacement of the motor.

For safety purposes the rocket must have a blunt tip, foam, or vacu-form nose cone. (Note: This is my own opinion. Not sure of the failure rate with lawn darts of other forms of competition but I am guessing it isn't rare. In this case, I think we can anticipate some lawn darts. I don't think anybody is likely to get hurt by a blunt tip, foam, or vacu-form nose cone flying on C and under motors.) @BEC , would it be a better sell to leave this out?

41.3 Classes
This event is divided into classes based on the permissible total impulse of the motor(s). The following classes of
Horizontal Spin Recovery Duration are established:
Motor
1/8A Class Multi-Round Maximum NRC Maximum 40 sec
1/4A Class Multi-Round Maximum 60 sec NRC Maximum 180 sec
1/2A Class Multi-Round Maximum 120 sec NRC Maximum 360 sec
A Class Multi-Round Maximum 180 sec NRC Maximum 540 sec
FAI A 300 sec
B 240 sec
C 300 sec

 

[BABAR]

Given no objections, I’ll run it up the flagpole and see if it makes a splash.

 

[astronwolf]

Put this in as a Provisional Event as per Rule 15. Provisional events don't go through the RCP process.

I'd take out the "FAI A" class for this event. There is no corresponding event in the FAI spacemodeling rules like there is for streamer, parachute, helicopter, etc.

If I had to vote on this today I'd vote "no." Not because I hate the event, but because your described scope of the event is too complicated for my little brain to understand. Simplify it. Also, if this is a "land shark" type event I would vote "no."

my two cents...

 

[Art Upton]

Seems to me this is simply "Back Slider Duration" ; See Peter Alway's Back Slider rockets.

 

[BABAR]

Horizontal Spin Recovery (HSR) and Back Slide Recover (BSR) have a lot of similarities, but are not quite the same.

They are similar in that they both transition from Vertical boost to horizontal recovery orientation with NO physical change in rocket shape or CG (aside from burnt propellant and ejection charge.)

They both use a side port "puff" to INITIATE the transition by radically orienting Angle of Attack (AOA.)

The difference is the MANNER of the actual transition FROM an unstable state post "puff" to a stable HORIZONTAL orientation.

HSR uses fins which are parallel to long axis of rocket, but curved or angle relative to the other two axes. These induce no drag or rotation during BOOST, but once puff throws off AOA, the fins induce spin in the falling "non-vertical" rocket (even if a leeeeeetle bit unvertical), which create a positive feedback loop that brings the rocket horizontal to the direction of fall (earthward.) The horizontal orientation is very high drag and slows the rocket.

BSR uses the puff to likewise induce a high AOA, at High AOA the rocket isn't stable and the rocket settles into a horizontal glide tail first.

With both, there is a risk that if "post-puff" the orientation of the rocket is nose down vertical or NEAR vertical (very LOW AOA as the rocket begins to fall) the rocket will RESUME stability and come in ballistic (failed transtion). From my experience, the magnitude of the "off-vertical" orientation required for FAILURE is lower with BSR than HSR, meaning that the probability of failure is HIGHER with BSR than HSR.

Because BSR is (IMO and experience) more prone to failure, I don't think it would be a great candidate for competition. I have no experience with competition, but something tells me the NAR RSOs are going to frown on a category with a relatively high failure rate, when failure means ballistic recovery.

The failure rate for HSR is pretty darn low when these things are built even half-way decently (maybe @Dotini can chime in), so I think it would make a good choice.

 

[Dotini]

The failure rate for HSR is pretty darn low when these things are built even half-way decently (maybe @Dotini can chime in), so I think it would make a good choice.

We got to the point where we could do 10 or even 20 consecutive flights over two sessions without mishap, with the limiting problem being moisture build up in the paper tube. Preventing fin failure is a challenge, but doable. Working with BT-5 or BT-20 tubes is the best guarantee of success, but the pleasure of seeing a BT-50 spinning at over 300 rpm and spiraling back down to your feet with a duration of over 40 seconds is a real thrill.

 

[BABAR]

We got to the point where we could do 10 or even 20 consecutive flights over two sessions without mishap, with the limiting problem being moisture build up in the paper tube. Preventing fin failure is a challenge, but doable. Working with BT-5 or BT-20 tubes is the best guarantee of success, but the pleasure of seeing a BT-50 spinning at over 300 rpm and spiraling back down to your feet with a duration of over 40 seconds is a real thrill.

my eccentric tube fin BSRs are coming close to that, but I don’t have nearly your number of tests!

 

[Dotini]

my eccentric tube fin BSRs are coming close to that, but I don’t have nearly your number of tests!

Well, to be honest, I live near 40 Acres, have a close friend, a degreed engineer, who is my build and launch partner, and have a functionally unlimited budget for building paper and plastic model rockets.

I haven't been active lately due to problems with health and home.

 

[BABAR]

Well, to be honest, I live near 40 Acres, have a close friend, a degreed engineer, who is my build and launch partner, and have a functionally unlimited budget for building paper and plastic model rockets.

I haven't been active lately due to problems with health and home.

Prayers and good wishes to you, my friend!

Your contributions are missed

 

[Al_delaIglesia]

Prayers and good wishes to you, my friend!

Your contributions are missed

Could you please send me photos, videos, plans or other documentation of your HSR models?

 

[Dotini]

@ Al_delaIglesia​

Please refer to the thread "Horizontal Spin Recovery - with Magnus Effect?"

You will find it on page 4 of the Scratch Built sub-forum.

 

[Al_delaIglesia]

@ Al_delaIglesia​

Please refer to the thread "Horizontal Spin Recovery - with Magnus Effect?"

You will find it on page 4 of the Scratch Built sub-forum.

ok, I read all 22 pages and watched the videos.
Could you document how many people have tried to fly this "event"?

fundamentally... so you want HSR to be an event because it is a combination of gliding and autorotating?

BTW, Backsliders have already been flown in rocket glide events, so they have a place in competition already.

 

[Dotini]

ok, I read all 22 pages and watched the videos.
Could you document how many people have tried to fly this "event"?

fundamentally... so you want HSR to be an event because it is a combination of gliding and autorotating?

BTW, Backsliders have already been flown in rocket glide events, so they have a place in competition already.

Sorry you read all that and got nothing.
Personally, I don't care anymore - or at least not at the moment. Check with @BABAR for any additional information.
Good luck.

 

[Al_delaIglesia]

Sorry you read all that and got nothing.
Personally, I don't care anymore - or at least not at the moment. Check with @BABAR for any additional information.
Good luck.

sorry you feel that way...
I guess I was really trying to reply to BABAR anyway

 

[Dotini]

sorry you feel that way...
I guess I was really trying to reply to BABAR anyway

FWIW, I recommend that HSR not become a formal competition.

 

[Al_delaIglesia]

FWIW, I recommend that HSR not become a formal competition.

understood, my mistake in responding to your post rather than BABAR

 

[BABAR]

Could you please send me photos, videos, plans or other documentation of your HSR models?

First, by far the best on this isn’t my work, the gold mine is here

Some of my stuff

This is my first SUCCESSFUL one, and I think the post that got @Dotini interested. He has really run with it, he is far too modest in his description of his accomplishments. Although Bail Out Bill cheats, I dump the nose weight.

https://www.rocketryforum.com/threads/bail-out-bill-and-the-horizontal-spin-recovery-rocket.147210/

This is one of my first successful TRUE HSR birds, with no configuration change.
https://www.rocketryforum.com/threa...quirt-no-recovery-system.165609/#post-2129308

The technique works VERY well for black powder long gap stage booster recovery. It is IMO one of the simplest methods of preventing a long black powder booster from coming in ballistic.


https://www.rocketryforum.com/threa...flight-3-dog-night-post-12.64307/#post-693030

https://www.rocketryforum.com/threads/something-different-horizontal-spin.32395/



https://www.rocketryforum.com/threads/horizontal-spin-test-13-mm-one-inch-rings.180077/

This is the widest diameter version to my knowledge. Had a couple good flights.

https://www.rocketryforum.com/threa...r-wide-body-bt-80-horizontal-recovery.166124/

 

[Al_delaIglesia]

First, by far the best on this isn’t my work, the gold mine is here

Some of my stuff

This is my first SUCCESSFUL one, and I think the post that got @Dotini interested. He has really run with it, he is far too modest in his description of his accomplishments. Although Bail Out Bill cheats, I dump the nose weight.

https://www.rocketryforum.com/threads/bail-out-bill-and-the-horizontal-spin-recovery-rocket.147210/

This is one of my first successful TRUE HSR birds, with no configuration change.
https://www.rocketryforum.com/threa...quirt-no-recovery-system.165609/#post-2129308

The technique works VERY well for black powder long gap stage booster recovery. It is IMO one of the simplest methods of preventing a long black powder booster from coming in ballistic.


https://www.rocketryforum.com/threa...flight-3-dog-night-post-12.64307/#post-693030

https://www.rocketryforum.com/threads/something-different-horizontal-spin.32395/



https://www.rocketryforum.com/threads/horizontal-spin-test-13-mm-one-inch-rings.180077/

This is the widest diameter version to my knowledge. Had a couple good flights.

https://www.rocketryforum.com/threa...r-wide-body-bt-80-horizontal-recovery.166124/

I read and understand all the variations, thank you for all that work (both you and especially Dotini).
I am focused on the interest in making HSR a provisional competition event.
I assume that you know that I am the NAR provisional event person.
Would it sound correct to categorize the event as a combination of gliding and autorotation?
Why do you feel the need to have a design constraint for the model to be "no moving parts"?

 

[Dotini]

Why do you feel the need to have a design constraint for the model to be "no moving parts"?

Why would you want or need moving parts when none are required to achieve the desired function? It is not elegant!

To paraphrase Thomas Aquinas, Nature does not ordain superfluity.

"Irrational creatures are not ordained to an end higher than that which is proportionate to their natural powers."

 

[Al_delaIglesia]

Why would you want or need moving parts when none are required to achieve the desired function? It is not elegant!

To paraphrase Thomas Aquinas, Nature does not ordain superfluity.

The use of moving parts may (or may not) enhance duration

 

[Dotini]

The use of moving parts may (or may not) enhance duration

The Alway brothers specified no moving parts. Van Milligan specified no moving parts. Moving parts are a corruption and perversion of the design philosophy. Get on board.

 

[Al_delaIglesia]

The Alway brothers specified no moving parts. Van Milligan specified no moving parts. Moving parts are a corruption and perversion of the design philosophy. Get on board.

I am not here to argue design philosophy.....the thread is about the possibility of a provisional event.

 

[BABAR]

Okay guys, this is a likely purely and academic discussion which may be boring to many. You have been warned!


I assume that you know that I am the NAR provisional event person.

unless I missed the email (quite possible) your post is the first response I have seen from NAR.


Would it sound correct to categorize the event as a combination of gliding and autorotation?

First, Gliding.

No.

Not sure if there is accepted terminology. I will refer to “forward” and “rearward” motion in respect to the long axis of the rocket (nosecone-ward and tail-fin-ward respectively.) using this, all rockets on boost are moving FORWARD and all gliders are moving FORWARD (usually, although BackSliders glide rearward.)

I will also refer to “vertical-lift” as force opposite gravity. Could also be referred to as “useful-lift”, as it is a force post ejection charge that retards descent. ALL falling bodies in the atmosphere generate drag, gliders generate an additional “vertical-life” which requires significant forward (or rearward) velocity.

Using this , HSR has no significant forward or rearward velocity post deployment, and aside from drag is definitely not generating any other “vertical-lift.” So not a glider in any way,


Second, AutoRotation.

A bit tougher, but I’d still say no. IMO rockets using AutoRotation are orienting longitudinally either nose up or nose down and deploying rotors, brakes, fins, or other structures perpendicular to the direction of fall to create additional drag and/or lift.

I concede that this technique uses aerodynamics to generate spontaneous rotation around the long axis of the rocket, which is what AutoRotation rocket do. However, the EFFECT of the rotation is dramatically for HSR. By using physics (I think it’s law of conservation of momentum) to orient the rocket horizontally relative to the direction of fall. Without changing any configuration, the rocket is shifted from position of minimum drag (launch/boost/ballistic) position with zero angle of attack to MAXIMUM drag position 90 degree angle of attack. This allows the combination of the body tube and the average cross section surface area of the fins to create drag. This use of the body tube cross sectional area explains why longer rockets work better (although the Turbinator worked with a BT-80, that was kinda fun!)

I just don’t think it really fits in this category.


Why do you feel the need to have a design constraint for the model to be "no moving parts"?


Aside from saucers and Back Sliders, I think HSR is the only recovery strategy that doesn’t require either a physical configuration change or a weight shift for safe recovery. HSR CAN be achieve WITH a weight shift (easiest way is to dump the nose cone), but I think that is “cheating.” Also, many competition categories require the rocket come down in one piece.

Anyway, I think many categories of competition have restrictions which make things challenging, and IMO the requirement for no moving parts adds to the challenge, uniqueness, and cool factor,

.

Could you document how many people have tried to fly this "event"?


Ummmmm, 2?

 

[Al_delaIglesia]

Okay guys, this is a likely purely and academic discussion which may be boring to many. You have been warned!


I assume that you know that I am the NAR provisional event person.

unless I missed the email (quite possible) your post is the first response I have seen from NAR.


Would it sound correct to categorize the event as a combination of gliding and autorotation?

First, Gliding.

No.

Not sure if there is accepted terminology. I will refer to “forward” and “rearward” motion in respect to the long axis of the rocket (nosecone-ward and tail-fin-ward respectively.) using this, all rockets on boost are moving FORWARD and all gliders are moving FORWARD (usually, although BackSliders glide rearward.)

I will also refer to “vertical-lift” as force opposite gravity. Could also be referred to as “useful-lift”, as it is a force post ejection charge that retards descent. ALL falling bodies in the atmosphere generate drag, gliders generate an additional “vertical-life” which requires significant forward (or rearward) velocity.

Using this , HSR has no significant forward or rearward velocity post deployment, and aside from drag is definitely not generating any other “vertical-lift.” So not a glider in any way,


Second, AutoRotation.

A bit tougher, but I’d still say no. IMO rockets using AutoRotation are orienting longitudinally either nose up or nose down and deploying rotors, brakes, fins, or other structures perpendicular to the direction of fall to create additional drag and/or lift.

I concede that this technique uses aerodynamics to generate spontaneous rotation around the long axis of the rocket, which is what AutoRotation rocket do. However, the EFFECT of the rotation is dramatically for HSR. By using physics (I think it’s law of conservation of momentum) to orient the rocket horizontally relative to the direction of fall. Without changing any configuration, the rocket is shifted from position of minimum drag (launch/boost/ballistic) position with zero angle of attack to MAXIMUM drag position 90 degree angle of attack. This allows the combination of the body tube and the average cross section surface area of the fins to create drag. This use of the body tube cross sectional area explains why longer rockets work better (although the Turbinator worked with a BT-80, that was kinda fun!)

I just don’t think it really fits in this category.


Why do you feel the need to have a design constraint for the model to be "no moving parts"?


Aside from saucers and Back Sliders, I think HSR is the only recovery strategy that doesn’t require either a physical configuration change or a weight shift for safe recovery. HSR CAN be achieve WITH a weight shift (easiest way is to dump the nose cone), but I think that is “cheating.” Also, many competition categories require the rocket come down in one piece.

Anyway, I think many categories of competition have restrictions which make things challenging, and IMO the requirement for no moving parts adds to the challenge, uniqueness, and cool factor,

.

Could you document how many people have tried to fly this "event"?


Ummmmm, 2?

I sent you an email to continue this conversation.

 

[astronguy]

Why bother? It looks like virtually no NAR Sections actually fly competition anymore. Did I miss something?

Brian

 

[Art Upton]

Why bother? It looks like virtually no NAR Sections actually fly competition anymore. Did I miss something?

Brian

My Section Does, JMRC right along with Sport and High Power Rockets. Even seen FAI testing

 

[Al_delaIglesia]

Why bother? It looks like virtually no NAR Sections actually fly competition anymore. Did I miss something?

Brian

what evidence are you basing this conclusion on?

 

[astronguy]

what evidence are you basing this conclusion on?

I researched the NARAM actual participation numbers in NAR competition, not the sport launch, going back about 20 years. The numbers are very low. Also, the NAR website has a search feature to find sections hosting competitions. Out of 9000 members, competition is relatively non-existent.

 

[Al_delaIglesia]

I researched the NARAM actual participation numbers in NAR competition, not the sport launch, going back about 20 years. The numbers are very low. Also, the NAR website has a search feature to find sections hosting competitions. Out of 9000 members, competition is relatively non-existent.

You wrote previously that " virtually no NAR Sections actually fly competition anymore."
The data that you claim to have researched, but not provide, says nothing as to section activity in competition. Many sections hold sanctioned competition launches according to the launch windows on the NAR website, so, no your statement is not true.
As to the number of competition flyers, yes the number may be a certain value that you consider to be non-existent, but what do you mean by non-existent?
A 1-2% participation rate may actually be quite appropriate. For example, in my coaching of FIRST robotics, I found that I could only get about a 1% participation rate from my high school students.
Also, competition flying costs the NAR nothing....NARAM and other competitions are entirely self funded.
As to your statement "Why bother?"...
I would like to see the numbers larger as I think that competition is fun and so may others that have not tried it or done it lately.
I also would like to see youth participation increase as it is a STEM activity that can benefit many students. This is currently growing as seen in FAI, ARC and other competitions.
I think that flying rockets is fun in many ways, so we should be encouraging others, not discouraging.

 

[astronguy]

You wrote previously that " virtually no NAR Sections actually fly competition anymore."
The data that you claim to have researched, but not provide, says nothing as to section activity in competition. Many sections hold sanctioned competition launches according to the launch windows on the NAR website, so, no your statement is not true.
As to the number of competition flyers, yes the number may be a certain value that you consider to be non-existent, but what do you mean by non-existent?
A 1-2% participation rate may actually be quite appropriate. For example, in my coaching of FIRST robotics, I found that I could only get about a 1% participation rate from my high school students.
Also, competition flying costs the NAR nothing....NARAM and other competitions are entirely self funded.
As to your statement "Why bother?"...
I would like to see the numbers larger as I think that competition is fun and so may others that have not tried it or done it lately.
I also would like to see youth participation increase as it is a STEM activity that can benefit many students. This is currently growing as seen in FAI, ARC and other competitions.
I think that flying rockets is fun in many ways, so we should be encouraging others, not discouraging.

It is a matter of percentages. Please feel free to post your supporting data. I'd like to see where your info comes from. I don't want to argue, but I back up what I say. FAI, ARC and other competitions are not NAR Competition or under the control of the NAR.

https://www.nar.org/find-a-launch/contest-launches

https://www.nar.org/find-a-local-club/nar-map-locator

The same few NAR sections are flying competition .

​