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micro max sidwinder ?

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ace

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hey guys
i was wondering if micromax sidewinders exist?
im looking for rocket to mount on a scale f16 as decoration

how can i build rockets can i just lathe them out of solid wood (or will that be to heavy) what can i use for fins
where should the CG be? what is the maximum mass for a micromax?
 

MarkII

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There aren't any Micromaxx kits of the Sidewinder that I know of, but Micromeister may have scratch-built one and if so, he probably has plans for it. You build Micromaxx rockets just like you build other types of model rockets; there are several sources online for standard parts like body tubes, nose cones and centering rings. You can design them in RockSim (and probably OpenRocket, too, although I have never used it) and the program will indicate the Center of Pressure and Center of Gravity for your design.

Major online sources for Micromaxx parts are

FlisKits http://www.fliskits.com/products/rocketkits/mmx_main_fs.htm

Balsa Machining Service http://www.balsamachining.com/

Aerospace Speciality Products http://www.asp-rocketry.com/

Leading Edge Rocketry http://leadingedgerocketry.com/catalog/sport_kits.html

and, of course, Quest Aerospace http://www.questaerospace.com/index.asp

Gordie at Excelsior Rocketry may be able to make decals for your model, too. http://www.excelsiorrocketry.com/

Mark K.
 

powderburner

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Ace,

Are you thinking of launching these things from an R/C airplane? If you do, you're never going to find them again!

The smallest size you will be able to scale down to would be about 1-18th (5.6%) using BT 2.5 tubing for the 5-inch 'winder body. The next size up would be about 1-13th (7.5%) using BT 3 tubing. (Tubing and other building components available from Fliskits and other vendors.) Either one of these (launched when your R/C acft is flying at 100 ft) will be invisible from the ground--literally. If you knew how easy it is to lose one of these little dudes from a static launch on the ground, you might think twice.

You may as well hear about it now, but you are treading on some sensitive ground for the rest of us model rocketry fans. I know that as a scale R/C guy you are probably just excited about modeling a bit of scale ordnance that actually launches. I doubt you have any plans/delusions of ever placing a matching seeker on the nose of that MMX AIM-9, and actually trying to hit another airplane (R/C or full-size) with it, but that is exactly what our rocketry hobby been accused of. And the bigger you make your air-launched scale 'winder, the more some DC moron is going to start worrying about how much warhead your rocket could carry.

The Feds have hinted that our rockets are dangerous because we could shoot down airliners and junk like that. Here you are with a project that would (to an ignorant lawyer/bureaucrat who doesn't have a clue how difficult/impossible it would be to develop a seeker head) seem to be right down that avenue. It doesn't make me too happy to be inviting the gov't to come back at us again.

Said all that to say this: Please be careful with what you write.

But back to pure model rocketry; you really will just see a puff, and that rocket will be gone.

http://www.rocketryonline.com/jimball/jimball/sidewinder/sidewinder.htm
http://www.rocketryonline.com/jimball/alway/images/sidewinder-b-color.gif
 
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Micromeister

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As several have mentioned 1:18 scale using minimum diameter T2+ tubing is as small is possible for MMX flight use. For display only turning form basswood has been done down to 1:144th scale. Personally I like Basswood for turning very small part better them most other woods because of it's tight straight grain, allowing smaller diameters to be "finished" if you will.

I do have a one-page plan for the AIM-9L as Mark mentioned, but have not released it yet as the forward fins MUST be mounted to freely flag during flight or the model is unstable. At this scale getting these tiny steering fins to weather vane during flight is a real pain, Making them look good as well, even hard with .020" music wire pivots.
I'm making 4 for use on my 1:18th scale 3 D12 clustered PMC F-104. thought I had a couple construction pics of the Sidewinders but can't put my finger on them at the moment. I'll post them when they turn up.
 
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ace

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hey guys
first of al thanx for the quick reply
im not really planning on firing them while airborne they are more for decoration but i want them functional just for the bragging rights
also i live halfway across the world from you guys, we don't have the same laws here (as long as it stays under 4500feet its legal)

about that rockets sim will the same physics apply when firing it horizontally

Rocksim keeps showing it unstable no matter what I try.
it says that its over stable does that main the same thing as unstable

@ micro meister
i would love to see pictures of your f104
how are you planning to mount your rockets (how do you built rails)
 

Micromeister

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hey guys
first of al thanx for the quick reply
im not really planning on firing them while airborne they are more for decoration but i want them functional just for the bragging rights
also i live halfway across the world from you guys, we don't have the same laws here (as long as it stays under 4500feet its legal)

about that rockets sim will the same physics apply when firing it horizontally


it says that its over stable does that main the same thing as unstable

@ micro meister
i would love to see pictures of your f104
how are you planning to mount your rockets (how do you built rails)
the model will have 4 Aim-9L sidewinders when completed. 2 on an under fuselage rack and one on each wingtip. The wingtip racks are being scratch built using sheet and bar styene, while under fuselage rack came with the model. Heres are a couple of the construction pics.. still haven't found the other dics with the Sidewinder construction but did come across the 1: 17.779 scale 1-page plan pdf drawing if it'll help.

469p1-sm_F104G_1-18th Base Construction Complete Wheels down_08-19-07.JPG


469p2-sm_F104G 1-18th Base completed Wheels Up_08-26-07.JPG


469q1-sm_WingTip Sidewinder Launch rail templates_08-31-07.jpg


View attachment MM 3xxc1_Sidewinder AIM-9L_07-25-06.pdf
 

powderburner

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John, I hate to tell you this, but (in the second pic) the ventral fin is on backwards

Extremely not scale
 

Micromeister

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John, I hate to tell you this, but (in the second pic) the ventral fin is on backwards

Extremely not scale
Yeap; I noticed the mistake after finishing construction..we all make silly goofs now and then.

Since its backwards orientation shouldn't effect the models flight and She is a Sport flying PMC it really wasn't worth trying to change the ventral fin.
Still a very nice 1/18th scale model of my 2nd favorite aircraft, Sorry if the mistake was that offensive, My bad entirely.
 

ace

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@ micromeister
thank you very much for that drawing
i made my first sidewinder today
its not really a scale model its just to test if its stable in a horizontal launch and to see how it clears my f16 rails

i have a small question
can you reuse those rocket motors ?
i used to reuse estes motors by filling them up with rcandy but im not sure if it will work with such a small motor

and what would happen if you would plug the back end of a micromax motor
im planning to do this so that the ejection charge won't destroy my rocket
 

powderburner

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Hey ace,

(yeah, I know I'm not Micromeister)...(whew)

Your launch trajectory (if you try it) depends on a few assumptions.
1) The parent model acft (the launcher) is in straight and level flight
2) The launch rod is pointed straight ahead on the parent acft
3) The model rocket experiences a "normal" launch.....that is, it does not have a "tip-off" accident at the end of the launch rod that turns the missile in some other direction

Under these somewhat idealized conditions, the model rocket would initially travel straight ahead, out in front of the parent model acft. (Let's hope you don't have a hangfire, or that your model rocket is not located on a wingtip station.) When in free flight the model rocket will immediately come under the influence of gravity and begin to follow a classic ballistic trajectory. It will begin turning toward the ground.

What you may not know is that the delay charge on these MMX motors only lasts for like literally one second. The missile is not going to get very far (or fall very far toward the ground) before the ejection charge deploys the recovery system.

Does that tell you what you wanted to know about physics of a horizontal launch?


As to what happens if you plug the nozzle, a few folks have accidentally run into that exact condition. They tried using the tip of a toothpick to hold the electrical igniter in place and the toothpick plugged the exhaust nozzle. The motor blew up. Now if you actually meant to ask what happens if you plug the front end of an MMX motor, I can't do more than guess because I have never tried it or heard of anyone else trying it. But if your model Sidewinder was in free flight at the point where the ejection charge ignites, and you designed the model rocket the normal way (with a separating nose cone and a streamer or parachute), the ejection charge would pop out the recovery system and the model rocket would make a normal descent and recovery. It would not "blow up" or rip apart the body tube.

Your chances of reloading the propellant grain on one of these is somewhere between small and none. Even if you could manage to perform such microsurgery, a used motor case would be unsafe and could easily let go when you ignite the reload. The reload process would be a WHOLE lot more bother than simply buying another motor (they cost like a whopping dollar).
 
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ace

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hey i didn't know that the delay was only 1 second im going to try to find some motors without a ejection charge
the problem is that my rocket is lathed out of solid balsa (with some lead in the nose for stability) so the explosion of the ejection charge would damage my fuselage
i wasn't talking about blocking the nozzle,but the other end i hope that the casing wil contain the ejection explosion

ill let you know how it works
 

Micromeister

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Ace:
Sorry for the very late reply.
more or less I have to ditto powderburners comments on horizontal launching of any model rocket.

It's also my understanding it is strictly against all safety and flying codes to launch any missile from a model aircraft in horizontal flight period. Please correct me if wrong on that point.

On my 1/18th F104 one of the option plans is to add a secondard launch system to the undercarrage rack to launch the two sidewinders just after the model clears the launch rod (TRAVELING UP) and allow them to deploy naturally at apogee/ejection. My plan was to add about 1/4° tow-out to both rails to sort of impart an opening V to the sidewinders flight path as they go which should get them out of the models general flight path on it's cluster of 3 D12-3's.
I don't really know if Powder has actually launched any micromaxx models but the MMX-II delays are NOT litterally 1 second. They average .857 seconds in both the standard MMX-II and the ejectionless MMX-II-NE. I can personally testify that in Staged flights this less then a second delay before upper stage ignition seems like an eternity. Coupled with the thrust time and acceleration of the model off the rails I don't think you'll have to worry about burning your F16 with the ejection but the motor thrust may singe some things as they leave the rails.

I won't worry about plugging the booster motor either, If your not really concerned about ejecting a recovery device (and you should be) then don't bother taping the motor in. At motor burn thru there will be enough pressure build up to kick the motor for the model without damage to the model itself. Personally I'd be using a small streamer or even just nose blow recovery and standard MMX-II motors which would allow the Sidewinders to be used over and over, also making them much more easily recovered rather then allowing them to lawndart into the ground.

NO; I wouldn't suggest trying to reuse the casings. It's been done with mixed results with both Sugar and AP but the resulting performance has ALWAYS been less then desired. Another item to consider If/when a casing wall is breached it'll really make of mess of your sidewinder and/or F16. Micro Maxx motors are such a small expence they really aren't worth the potential headache anyway;)
 
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MarkII

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To go along with what John said above, firing a single use motor like a Micromaxx II always erodes the inside of the case along with the nozzle. Some of the casing material in paper cases burns with the propellant. As a result, the case is thinner and weaker than it was before the motor was fired. Paper cases are simply not designed to be reused. Additionally, paper cases are used only with black powder motors; I don't know about sugar-based propellants, but AP motors usually need a much stronger case. So I don't think that refilling a paper SU case would work very well in any event. And as I said, the nozzle will be eroded anyway. At the very least, it won't be able to give the motor that same level of performance, and more likely it will just blow out.

Overriding all of these technical issues, though, is the safety factor. To put it bluntly, refilling an expendable motor case is a serious violation of the Safety Code, is dangerous, and is simply a stupid thing to do. I'm as interested in saving a buck as the next guy, but common sense says don't try it.

Mark K.
 

ace

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It's also my understanding it is strictly against all safety and flying codes to launch any missile from a model aircraft in horizontal flight period. Please correct me if wrong on that point.
it isn't illegal where i live and the club where i fly allows it
the field is also a nofly zone so there is no danger to general aviation

anyway it tried to launch them Sunday but the igniter didn't work
what kind of voltage and current do you guy's use
i tried it with an estes ignition power source (they use 4 AA batteries)
 

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