CiCi 2 Edmonds two stage black powder gap stage

[Rktman]

@georgegassaway web site shows plans for a canard boost glider where it looks like both canard and wing are perfectly coplanar.

It’s similar to the CiCi except it has a pop pod

https://georgesrockets.com/GRP/CONTEST/BRB_contest/GliderPlan/GliderPlan.pdf
Interesting as the CiCi because it is a rocket glider as opposed to pop pod has to carry weight of a nose cone and body tube and launch lug up front. That said, the red picture from this of George’s posts

https://georgesrockets.com/GRP/CONTEST/BRB_contest/GliderPlan/Half-A_BoostGlider.html
Shows he added a bit of clay nose weight, but hardly the same as a Viking Nose Cone and a body tube and launch lug and motor mount.

IIRC George's glider has about 3 degrees of negative canard incidence while the main wing has none.

 

[BABAR]

IIRC George's glider has about 3 degrees of negative canard incidence while the main wing has none.

You’re right, I hadn’t seen it.

Still had me wondering about the CICi 1 and 2 and the sustainer, as I said, it is hard to tell from the scans.

Thanks, mi amigo!

 

[Rktman]

You’re right, I hadn’t seen it.

Still had me wondering about the CICi 1 and 2 and the sustainer, as I said, it is hard to tell from the scans.

Thanks, mi amigo!

Let me know if you need help measuring anything like length or angles. I can measure things like angles down to a fraction of a degree by tracing things out in Adobe Illustrator.

 

[BABAR]

Let me know if you need help measuring anything like length or angles. I can measure things like angles down to a fraction of a degree by tracing things out in Adobe Illustrator.

SINCE YOU OFFERED!

That could definitely help. If you would, please

1. Using the CiCi single stage. https://www.spacemodeling.org/jimz/other/edmonds_cici.pdf
Measure the difference in incidence angles on the fuse for the canard and the wing

Also, measure the differences in angle (if any, they may be parallel) between the top and bottom surfaces of the motor mount. If parallel, the body tube is mounted parallel to the canard, otherwise it is probably parallel to wing.

2. Using the CiCi2. https://www.spacemodeling.org/jimz/other/edmonds_cici_2.pdf

I think the difference in angles between the top and bottom surfaces of the booster boom equate to the incidence differences between the canard and the wing.

Also check the top and bottom surfaces of the mount, again is the parallel?

Also measure the HEIGHT OF THE sustainer mount (assuming it is parallel), not including the excrescent section that fits in the notch. I have an idea that may help set up perfect alignment on my modification.

 

[Rktman]

SINCE YOU OFFERED!

That could definitely help. If you would, please

1. Using the CiCi single stage. https://www.spacemodeling.org/jimz/other/edmonds_cici.pdf
Measure the difference in incidence angles on the fuse for the canard and the wing

Also, measure the differences in angle (if any, they may be parallel) between the top and bottom surfaces of the motor mount. If parallel, the body tube is mounted parallel to the canard, otherwise it is probably parallel to wing.

2. Using the CiCi2. https://www.spacemodeling.org/jimz/other/edmonds_cici_2.pdf

I think the difference in angles between the top and bottom surfaces of the booster boom equate to the incidence differences between the canard and the wing.

Also check the top and bottom surfaces of the mount, again is the parallel?

Also measure the HEIGHT OF THE sustainer mount (assuming it is parallel), not including the excrescent section that fits in the notch. I have an idea that may help set up perfect alignment on my modification.

Whew, been a long yard work day tidying up for winter, I'll jump on it first thing tomorrow and get you some angles.

 

[BABAR]

Whew, been a long yard work day tidying up for winter, I'll jump on it first thing tomorrow and get you some angles.

Hey, I’m grateful for the help. Nothing urgent about this.

 

[Blast it Tom!]

One thing about angles (in my limited experience)- they are right devils to lay out correctly. Especially small angles. What I've done on my table saw is to use a "rise-run" approach, say, measure down 10 inches and over .25" or whatever it is. Seems to work better. A half a degree of error projecting from a protractor is .105" off a foot away, whereas if you find your angle, laying out using rise/run seems to work better. Just a thought.

 

[Rktman]

1. Using the CiCi single stage. https://www.spacemodeling.org/jimz/other/edmonds_cici.pdf
Measure the difference in incidence angles on the fuse for the canard and the wing

Also, measure the differences in angle (if any, they may be parallel) between the top and bottom surfaces of the motor mount. If parallel, the body tube is mounted parallel to the canard, otherwise it is probably parallel to wing.
The link you provided above is for the CiCi single stage offset pylon, vs the (original?) kit version with the integrated pylon.

The canard has a negative 3° incidence relative to the main wing (if we assume the main wing is “level”). The motor mount is parallel to the main wing once it is mounted to the 3° down-canted canard.

2. Using the CiCi2. https://www.spacemodeling.org/jimz/other/edmonds_cici_2.pdf
I think the difference in angles between the top and bottom surfaces of the booster boom equate to the incidence differences between the canard and the wing.
The booster’s canard has a negative 3° incidence relative to the main wing (again if we assume the main wing is “level”). The bottom of the booster boom is at a different shallower angle and has nothing to do with any incidence between the canard and main wing.

Also check the top and bottom surfaces of the mount, again is the parallel?
The top and bottom surfaces of the mount are parallel, meaning the mount and motor tube are parallel to the main wing.

Also measure the HEIGHT OF THE sustainer mount (assuming it is parallel), not including the excrescent section that fits in the notch. I have an idea that may help set up perfect alignment on my modification.
Height of the sustainer mount (not including the tab that fits into the fuse notch) is 0.70” (11/16” or 17.8mm).

 

[Rktman]

SOLUTION FOR NOSE-HEAVY CONDITION

If your glider is nose-heavy, here's a tip that works well for me on my canard builds: increase the negative angle of the canard wing rather than adding unnecessary tail weight. Increase the angle in small increments (say, ½ a degree) until it corrects the problem.

If the canard is already glued down and you can’t adjust the angle, try trim tabs. Attach small flaps to the trailing edge of your canard and adjust those till it corrects the problem. Here’s an example of what I'm describing:


In this case, I sandwiched a thin piece of aluminum between two 1/64" pieces of ply to form the trim tab and glued the other end of the aluminum to the flap trailing edge. It allows me to bend the trim tab down incrementally until the problem is solved. Once the angle is right I just lock the trim tab in place with some thick CA between the flap TE and the trim tab. Hope this helps.

 

[georgegassaway]

@georgegassaway web site shows plans for a canard boost glider where it looks like both canard and wing are perfectly coplanar.

If by "coplanar" you mean parallel, heck no.

Look at the pattern for the fuselage (blue). It is angled "up" for the canard, a couple of degrees or so, while the main wing is parallel to the rest of the fuselage.

 

[georgegassaway]

SOLUTION FOR NOSE-HEAVY CONDITION
......
If the canard is already glued down and you can’t adjust the angle, try trim tabs. Attach small flaps to the trailing edge of your canard and adjust those till it corrects the problem. Here’s an example of what I'm describing:

View attachment 437780

Unfortunately this can introduce some frustrating trim stability issues. A Canard design needs for the canard to STALL before the main wing stalls. Adding flaps like that may tend to make the canard take longer to stall, so the main wing may stall first.

Long long ago, I made a canard design where the canard was flat for boost, then was hinged for the rear half to come down a few degrees for glide. It ran into this problem, because undercambered wings can fly slower than non-undercambered wings. It was very pitch sensitive. At one point I added enough noseweight that I thought "solved" the problem. But I realized that the fuselage was pointing down a few degrees in glide, more than it should have and the canard was semi-stallled to allow the glider to be gliding faster and "nose down" compared to what it should have been. But I had no way to fix that problem because it needed to have the canard flat (parallel) on boost. Well I solved it a LITTLE, I adjusted the deployment angle of the flap to be as little as I could get away with, moving the CG back a bit, and the pitch trim was not as bad since the canard did not stall as soon.. But I was never happy with that, it was a compromise to get a sucky model to fly less sucky.

On a later canard design, I solved it in an odd but effective way, making up a T-rail for the canard to slide back about 10 inches for boost, then at ejection it slid forward, and the forward end of the rail was angled up 2-3 degrees. Not elegant, but effective. Ironically it shredded the main wing when using a motor I didn't think would do that to it, and I never tried it again.

I will note that a lot of the Bruce Blackistone "Valkyrie" canards of the 1970's suffered this same problem. IIRC some of them used the hinged flap method. And I first ran into that weird pitch trim sensitivity when I built a copy of the design.

I've not done canards very much since. But when I have, the canard was tack-glued on for two reasons. One,. to adjust the incidence angle. The other, in case the canard size didn't seem ot be right, so I could replace it. Only after finding the sweet spot for the trim I did I glue it on and "freeze" the design.

Canards are odd ducks......

 

[BABAR]

Will a canard design work with a deplorable elevon on the back of the WING?

 

[Aeronerd]

Unfortunately this can introduce some frustrating trim stability issues. A Canard design needs for the canard to STALL before the main wing stalls. Adding flaps like that may tend to make the canard take longer to stall, so the main wing may stall first.

Long long ago, I made a canard design where the canard was flat for boost, then was hinged for the rear half to come down a few degrees for glide. It ran into this problem, because undercambered wings can fly slower than non-undercambered wings. It was very pitch sensitive. At one point I added enough noseweight that I thought "solved" the problem. But I realized that the fuselage was pointing down a few degrees in glide, more than it should have and the canard was semi-stallled to allow the glider to be gliding faster and "nose down" compared to what it should have been. But I had no way to fix that problem because it needed to have the canard flat (parallel) on boost. Well I solved it a LITTLE, I adjusted the deployment angle of the flap to be as little as I could get away with, moving the CG back a bit, and the pitch trim was not as bad since the canard did not stall as soon.. But I was never happy with that, it was a compromise to get a sucky model to fly less sucky.

On a later canard design, I solved it in an odd but effective way, making up a T-rail for the canard to slide back about 10 inches for boost, then at ejection it slid forward, and the forward end of the rail was angled up 2-3 degrees. Not elegant, but effective. Ironically it shredded the main wing when using a motor I didn't think would do that to it, and I never tried it again.

I will note that a lot of the Bruce Blackistone "Valkyrie" canards of the 1970's suffered this same problem. IIRC some of them used the hinged flap method. And I first ran into that weird pitch trim sensitivity when I built a copy of the design.

I've not done canards very much since. But when I have, the canard was tack-glued on for two reasons. One,. to adjust the incidence angle. The other, in case the canard size didn't seem ot be right, so I could replace it. Only after finding the sweet spot for the trim I did I glue it on and "freeze" the design.

Canards are odd ducks......

I don’t want to hijack Babar’s thread, just pointing out that the CiCi doesn’t use an undercambered wing and it doesn’t use canard flaps.

Anyway the canard wing is glued already so he can’t change the angle and he used a heavier nose cone an heavier balsa for the rudders so it threw the balance off and maed it nose heavy. Seems to me putting in those “trim flaps” is the only way he can adjust the canard angle now to see what works when he’s trimming it. Then he can freeze in the right angle with glue. Just my 2 cents.

 

[Rktman]

Since I had to trace everything to get those angles and answers, I thought I’d make those tracings available as pdfs. They’re full-sized on Tabloid sized paper (11” x 17”) and you can tile your print if you don’t have the capability to print Tabloid.

If you PM me I can send the tracings in Illustrator format so that you can have the parts laser cut if you prefer.

 

[BABAR]

I don’t want to hijack Babar’s thread, just pointing out that the CiCi doesn’t use an undercambered wing and it doesn’t use canard flaps.

Anyway the canard wing is glued already so he can’t change the angle and he used a heavier nose cone an heavier balsa for the rudders so it threw the balance off and maed it nose heavy. Seems to me putting in those “trim flaps” is the only way he can adjust the canard angle now to see what works when he’s trimming it. Then he can freeze in the right angle with glue. Just my 2 cents.

Normally you would be correct, but I just cut the canard off, sanded in a SWAG angle (I am guessing somewhere between 3 degrees and 5 degree), and I will recut the forward CANARD, this time using 1/16” balsa (recycled from some of my previous helicopter rockets) which will cut down weight a bit (which should help since it is already nose heavy), and see how it flies.

I theeeeenk there must be some limits as @georgegassaway suggests on the maximum amount of negative incidence you can put on a ROCKET glider, although I am unsure if it is different than a boost glider. For distinction, if have appended the difference at the end of this post

The GLIDER phase of flight may be able to tolerate and indeed require a certain amount of negative canard relative to wing incidence. @georgegassaway commented that the canard needs to stall before the wing to work. PERFORMANCE wise (efficient glider flight) you likely want as little off-incidence as possible because it adds drag. For me, not an issue, I fly a medium field, I just like my gliders to come down without damage and not head over the fence.

I am not sure if off-incidence is as much of an issue for pop pod boost gliders as it is Rocket gliders, but too much (and I am thinking much over 3 degrees might BE too much) is gonna throw off the boost and make it do a half loop right into the ground. Ideally you want ZERO off-incidence on boost, mainly as it potentially (or at least intuitively) throws off a straight vertical flight. The additional drag (at least for a non-competition bird) really isn’t too much of an issue.


https://stason.org/TULARC/recreatio...fference-between-a-Boost-Glider-and-a-Ro.htmlWhat is the difference between a Boost/Glider and a Rocket/Glider?
In a Boost/Glider (referred to as a BG in the rest of the
FAQ), only a portion of the rocket as launched is required to
come down gliding. In a Rocket/Glider (RG), the entire model
remains in one piece, and the whole model glides down. BGs can
be higher performance because they do not have to carry the
dead weight of the motor while gliding down. But sometimes
that extra mass is helpful in trimming the model, and RGs have
the advantage of not having to chase multiple
pieces. Typically, this distinction is only important in NAR
competition, where these two classes are distinguished. An RG
is a legal entry in BG events, but a BG is not a legal entry
in RG events.

 

[Rktman]

Normally you would be correct, but I just cut the canard off, sanded in a SWAG angle (I am guessing somewhere between 3 degrees and 5 degree), and I will recut the forward CANARD, this time using 1/16” balsa (recycled from some of my previous helicopter rockets) which will cut down weight a bit (which should help since it is already nose heavy), and see how it flies.

I theeeeenk there must be some limits as @georgegassaway suggests on the maximum amount of negative incidence you can put on a ROCKET glider, although I am unsure if it is different than a boost glider. For distinction, if have appended the difference at the end of this post

The GLIDER phase of flight may be able to tolerate and indeed require a certain amount of negative canard relative to wing incidence. @georgegassaway commented that the canard needs to stall before the wing to work. PERFORMANCE wise (efficient glider flight) you likely want as little off-incidence as possible because it adds drag. For me, not an issue, I fly a medium field, I just like my gliders to come down without damage and not head over the fence.

I am not sure if off-incidence is as much of an issue for pop pod boost gliders as it is Rocket gliders, but too much (and I am thinking much over 3 degrees might BE too much) is gonna throw off the boost and make it do a half loop right into the ground. Ideally you want ZERO off-incidence on boost, mainly as it potentially (or at least intuitively) throws off a straight vertical flight. The additional drag (at least for a non-competition bird) really isn’t too much of an issue.


https://stason.org/TULARC/recreatio...fference-between-a-Boost-Glider-and-a-Ro.htmlWhat is the difference between a Boost/Glider and a Rocket/Glider?
In a Boost/Glider (referred to as a BG in the rest of the
FAQ), only a portion of the rocket as launched is required to
come down gliding. In a Rocket/Glider (RG), the entire model
remains in one piece, and the whole model glides down. BGs can
be higher performance because they do not have to carry the
dead weight of the motor while gliding down. But sometimes
that extra mass is helpful in trimming the model, and RGs have
the advantage of not having to chase multiple
pieces. Typically, this distinction is only important in NAR
competition, where these two classes are distinguished. An RG
is a legal entry in BG events, but a BG is not a legal entry
in RG events.

No, much over 3° is probably too much. I’ve never had to go more than 3.25° in total incidence to correct the 5 canard gliders that I’ve had a nose-heavy condition with. So far none have looped, but yes, 3 of those were BGs and I usually like to go a bit generous on the pop pod length anyway to bring the launch CG safely forward.

I’ve also had to add incidence where I’ve had way too little and the glider would stall as if it was tail-heavy. It would angle down steeply after apogee, then nose up, causing it to slow down to the point where it lost enough forward motion to drop the nose very steeply again. That made it pick up speed and it would then nose up and repeat the cycle, the porpoising getting increasingly more severe until it just lost so much forward glide speed it would then lawn dart after 3 or 4 cycles.

Lately I’ve resorted to temporarily attaching the canard wing on my clones and scratch-builts. I tack it on with cut down sewing needles and/or some rubber cement if needed. I admit it’s hard to get the angle exactly as in the plans because I hand cut my balsa parts. Also small differences in balsa weight/density and non-original components when cloning vs the original kits can throw things off.

At any rate, I’ll trim it and if things aren’t ideal, I still have the opportunity to gradually add more incidence or remove some with shims until it glides to my satisfaction. The real test comes when I maiden it. If things still aren’t right I can still adjust things.

Guess I’ve learned my lesson from previous gliders where I glued on the canard and couldn’t easily remove it without risking destroying the fuselage. In those earlier cases I resorted to the *trim tab solution and so far it’s worked every time. Also I hate having to resort to adding weight to my gliders unless there’s no other alternative.

*And giving credit where credit is due, the trim tab idea came from an R&D report that Rob Edmonds did titled "Self-Regulating Rocket Gliders".

 

[BABAR]

Since I had to trace everything to get those angles and answers, I thought I’d make those tracings available as pdfs. They’re full-sized on Tabloid sized paper (11” x 17”) and you can tile your print if you don’t have the capability to print Tabloid.

If you PM me I can send the tracings in Illustrator format so that you can have the parts laser cut if you prefer.

These are great!

The enemy of good is always better. I was thinking that you should submit these to the JimZ rocket site.
Not sure if the fuselages would fit (even if angled) on 8.5x14 cardstock with narrow margins. Also a ruler with inches and cm would be good on each page.

 

[BABAR]

My best guess

 

[Rktman]

My best guess

My best guess

Yikes, that looks like 5 degrees. Just tack it on for now, so you can still adjust the angle.

 

[BABAR]

As expected, 1/16” is 1/2 the weight of the 1/8”

 

[Rktman]

These are great!

The enemy of good is always better. I was thinking that you should submit these to the JimZ rocket site.
Not sure if the fuselages would fit (even if angled) on 8.5x14 cardstock with narrow margins. Also a ruler with inches and cm would be good on each page.

Tried but couldn't get fuselages to fit on 8.5 x 14 even if angled.
Put in a "This is 1 inch" box for reference.

 

[BABAR]

Sanded it down, I think this is about 3 degrees

 

[BABAR]

Kinda looks like a pelican!

 

[georgegassaway]

I don’t want to hijack Babar’s thread, just pointing out that the CiCi doesn’t use an undercambered wing and it doesn’t use canard flaps.

Anyway the canard wing is glued already so he can’t change the angle and he used a heavier nose cone an heavier balsa for the rudders so it threw the balance off and maed it nose heavy. Seems to me putting in those “trim flaps” is the only way he can adjust the canard angle now to see what works when he’s trimming it. Then he can freeze in the right angle with glue. Just my 2 cents.

Given this is a kit, it was designed with canard size and angles for a reason. To mess with the angle now, or adding flaps, or whatever to the canard, will mess up what happens when the second stage fires and it not longer has the first stage glider as a "mirror" to balance out anything that would be done equally to both canards.

Anyway, a FAR simpler fix: If it's nose heavy.....make it not be.

SOLVED.

The simplest fix is to add tailweight until the CG is back where it is supposed to be. It won't glide as well as if it were lighter, but it will glide better than being nose-heavy.

The BETTER fix, but not as simple, is to replace the heavy nose cone with a light one as it was designed to have to begin with. Even if you have to pry the whole pod off, and glue the light nose cone to a new motor tube (assuming you have spare tubing), that is a 10-minutes or less fix, if using CA glues. Yes this also presumes having or obtaining (or making) a lighter nose cone.

Now, on conventional (not canard) gliders with a fixed pod, a heavier nose cone would not cause as much of a problem since the pod is closer to the CG (say, the old Estes Falcon). But canard models make the weight of the engine pod far more of a factor if too heavy, because the glide CG is so far behind the pod than with a conventional glider. And if a conventional glider was nose-heavy, it would not take much tailweight to fix since the tail is SO far back from the glide CG.

 

[georgegassaway]

https://stason.org/TULARC/recreatio...fference-between-a-Boost-Glider-and-a-Ro.htmlWhat is the difference between a Boost/Glider and a Rocket/Glider?
In a Boost/Glider (referred to as a BG in the rest of the
FAQ), only a portion of the rocket as launched is required to
come down gliding. In a Rocket/Glider (RG), the entire model
remains in one piece, and the whole model glides down. BGs can
be higher performance because they do not have to carry the
dead weight of the motor while gliding down. But sometimes
that extra mass is helpful in trimming the model, and RGs have
the advantage of not having to chase multiple
pieces. Typically, this distinction is only important in NAR
competition, where these two classes are distinguished. An RG
is a legal entry in BG events, but a BG is not a legal entry
in RG events.

That is certainly the correct definition for contest models. Out in the rest fo the hobby world....the distinction tends to get lost. People who would say "Hey, its rocket powered and a glider, so it's a rocket glider" (even though it uses a pop-pod, or is a parasite glider, or pops the engine out).

Anyway, this is why I have tried to popularize this catch-all term:

ROCKET BOOSTED GLIDERS (or RBG, as opposed to B./G or R/G)

It's a generic term that covers hobby rocket models that uses rocket power for boost, then glides (hopefully).

The forum on TRF for gliders, that's the name of it: Rocket Boosted Gliders. That was a new forum added 15 years or so back. Originally it was going to be called "Rocket Propelled Gliders". Not only a term nobody used, but whose acronym, RPG, is an acronym for Rocket Propelled Grenade. I discussed with the moderators why it ought to be called Rocket Boosted Gliders. RBG's

https://www.rocketryforum.com/forums/rocket-boosted-gliders.44/
BTW - when the first gliders appeared in the hobby (around 1960-ish), they were called Boost Gliders. Then in 1970, a new contest event was created for gliders that stayed in one piece and ejected nothing, and that was called Rocket Glide. Both events still exist, and I've used rocket gliders in the boost glide event a lot of times. Anyway, B/G existed 10 years or so before R/G did.

 

[BABAR]

Given this is a kit, it was designed with canard size and angles for a reason. To mess with the angle now, or adding flaps, or whatever to the canard, will mess up what happens when the second stage fires and it not longer has the first stage glider as a "mirror" to balance out anything that would be done equally to both canards.

Anyway, a FAR simpler fix: If it's nose heavy.....make it not be.

SOLVED.

The simplest fix is to add tailweight until the CG is back where it is supposed to be. It won't glide as well as if it were lighter, but it will glide better than being nose-heavy.

The BETTER fix, but not as simple, is to replace the heavy nose cone with a light one as it was designed to have to begin with. Even if you have to pry the whole pod off, and glue the light nose cone to a new motor tube (assuming you have spare tubing), that is a 10-minutes or less fix, if using CA glues. Yes this also presumes having or obtaining (or making) a lighter nose cone.

Now, on conventional (not canard) gliders with a fixed pod, a heavier nose cone would not cause as much of a problem since the pod is closer to the CG (say, the old Estes Falcon). But canard models make the weight of the engine pod far more of a factor if too heavy, because the glide CG is so far behind the pod than with a conventional glider. And if a conventional glider was nose-heavy, it would not take much tailweight to fix since the tail is SO far back from the glide CG.

I am planning a redesign, will use a much lighter nose cone (although I will need a firm bulkhead, the vacuformed plastic is so thin I think the ejection charge would blow right through it!)

Will use a carbon fiber strip to reinforce the fuselage. I may add some dihedral to the wing of the booster, and outwardly angle the rudder fins on the sustainer so they should add a bit of effective dihedral.

Thanks again for the help.