Sono Tubes

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Neil

Well-Known Member
Well, I gone and done it again... I was playing with rsim... All my threads seem to start like that nowadays... So I thought it'd be kewl to call a rocket "Thunder Bird". So my first thought was: This has GOT to be a biggun'. it started out 7.5" with LOC tubing, but since I cant afford a nosecone from LOC, I would have to make the nosecone less than 40" cause thats as big as the late we want to get can hold... So it went down to 6"... I REALLY cant afford a PML fiberglass cone, but, I can make one on the lathe, so big whoop. But... Then I got thinking... I suggested a mongo sono-rocket before, and got slammed, but, this one would only be .5" bigger than the Nike Smoke and Emerald Star (cutting out the fins for that one soon...)... So... I was wondering... Since our local hardware store carries 6" sono tubes...

What goes into making a sono tube rocket? How do you prepare a sono-tube that size? The rocket in question would require 126" of tubing. 90" for the actual body tube, the rest for couplers. It would be chopped into two 45" sections, fincan and payload. I bet I could get my arm in there to get the wax layer off. How hard is it to peel off the waxed layer of paper? And once you do peel it off, how strong is it? Does it require glassing? It would have a central 54MM motor mount and a pair of 38MMs for an extra kick. I have gotten into the habit of adding outboards to all my new rsim designs (believe me, there are many. ), just cause I like em. Makes it a bit more complicated, but hey.

So, could you take me through (step by step) how you prepare a sono tube for rocketry purposes? i have wanted to make a sono-rocket for a while now, and seing as I cant afford PML 6" tubing in THIS lifetime... I would rather spend days getting a sono-tube ready then spend months saving up to buy a PML tube...

So this would be (somewhat) a "rocket on a budget". Sono-tube body, turned foam (then glassed) nose cone, all that stuff. I already have some 54MM and 38MM tubing, and I would use quarter inch ply for the fins... Or should I use 3/8" on a rocket this size? The rocket wouldent have a very big fin-span... Just 17" (thats about 5.5" semi-span). Could I get away with .25"?

This will be a winter project if I do it... Im going to finish the Emerald Star and Nike Smoke first, of course. Cant have 3 5-6" rockets going at once... thatd be pretty confusing...

Rsims ays itll be about 18# dry... Thats pretty scary (a single J350 wont lift it over 1K... I dont want to be playing around with dual deployment and 20 pound rockets at THAT altitude)... A K1275R will get about 4K... Put a pair of J350s in the ouboards, with the K1275R, and you get 7K... I guess I dont want it going THAT high, but hey. Maybe some Hs or Is in the outboards and a K550 in the middle... Anyways, its a bit early to be thinking about that. Ill worry about the rocket later... Right now I just want to know about sono tubes.

Thanx.

DPatell

Well-Known Member
Let the bashings proceed

Sonotube is okay for slower flying stuff. Sure, if you add enough composites to the mix you will have a tough tube.

I don't believe it to be too hard to peel the inner wax layer.

DO NOT peel the outside of the tube, sand it. I began to peel mine, and it does not peel off evenly, resulting in bubbles under my glass.

Definately fiberglass it, as sonotube is only paper, and not very high quality paper as it is intended to be biodegradable, anyways. If you're talking K1275R, go with a layer or 2 of 6oz. glass.

I currently have a 6" sonotube Der V3 upscale that has 2 layers of 4oz glass, and it seems pretty strong. I also have a section of 7.75" sonotube and a nosecone downstairs to fit it, the tube has 2 layers of 4oz as well. Pretty strong.

My dad has a 6.5" Sonotube Lil' Nuke upscale that has a single layer of 4oz. on it. Should be flying on a K550 before too long, I'll tell you how it goes.

Sure, cheap rockets are fun...but it's almost a waste to fly a motor in it that costs up to 3 or 4 times as much as the rocket...

...and you may want to increase your fin span. Usually want to keep it a single body diameter or more.

Neil

Well-Known Member
Why let the bashings begin? Y'all said "go for it" on rockets only half an inch smaller...

Great... I just LOVE sanding tubes... :kill: So, would I be better off to just bight the bullet and buy some PML phenolic tubing and glass it, or is Sono Tube good enough? Im slightly torn between spending a crapload of money and making a really good rocket, and spending a little money and building a really good rocket... So, spend a load of money or spend a little money? that is the question.... Whaddaya think?

Ill increase the fin span a bit and see what it looks like from there... So would it need quarter inch of 3/8" plywood? Would tip to tip glassing be neccesary for the punch of a K1275R? Thats the max motor i would want to fly it on...

This rocket would obviously be electronic deploment only, no motor deployment whatsoever.

Ryan S.

Well-Known Member
how tall are you making it? I dont think you should go that high, and if you think you are going to fly bigger motors, fly the rockets you have now, then say "hey I did this on my Nike smoke, but it didnt wokr really well, this time I am going to do something different"

Dont make the same mistakes twice

havoc821

Well-Known Member
I'm not trying to bash you but your way of doing things kinda makes me wonder.

1) Why do you "NEED" another 6" rocket? Can't you just enjoy what you have? Ok, so I do the same thing but I'm trying to not build more rockets and not end up flying them for another 6 months because I don't have the money for the motors.

2) Quote: It would be chopped into two 45" sections, fincan and payload.

What is with you and HUGE payload bays. Something this size needs to be dual deploy. Even if it is only a few thousand feet, you will still be walking a long ways and risk losing it. If you meant that the payload bay was for dual deploy, you should specify because when I hear payload bay, I think of.....well.... a payload bay for lofting eggs, altimeters, bugs, etc.

3) Quote:Rsim says itll be about 18# dry... Thats pretty scary (a single J350 wont lift it over 1K...

You need to learn the very important thing call THRUST to WEIGHT ratios. It is a good rule of thumb (or law) that you should have at least 5 times the "average" thrust as the weight of the rocket. 5:1, example, 1 lb rocket needs 5 lbs of average thrust. To see if you have enough thrust do this.

Take motor's newtons Example, J350 and divide it by 4.448 to get the pounds of thrust and you get 78.6870503. That is how many pounds of thrust the J350 has. Now didvide that by the weight of the rocket and you get 4.371502794. That means you have a ~4.4:1 thrust to weight ratio. In other words, not good. You would need a LONG rail or rod to get this rocket moving in the right direction. When you run simulations you need to look at not only the altitude and velocity, but read the report thingy and look at velocity at launch guide departure and see if it is fast enough.

4) If you can barely afford this rocket and it is made out of cheap stuff like sonotubes, you shouldn't be building it. If you can barely afford the parts how are you

1) going to afford the casings

??????????

I think you should get more experience in big L2 size rockets or any L2 rocket for that matter before you go crazy and building a big rocket each week. How many J,K,L flights have you done with rockets you designed yourself? Probably less than 3. I could be wrong. I like to dream about building big Porthos 2 size rockets all the time but dreaming and reality are 2 way diferent subjects. I could care less what you do but I'm just trying to get you off that one way street that only leads to your stubborness to accept others advice. No adult and especially not a 13 year old is capable of doing all these big projects within this much time that you have given yourself. You need to do one thing at a time, learn AS MUCH AS YOU CAN from it and move to the next thing. USE the stuff you learned and make use of it. Then see if you can learn anything else from the next rocket rather than flying through 4 rockets at a time and realize that you made the same mistake in all of them. I'm just trying to help, so sorry if I "bashed" to hard but you need to approach this L2 size rocket thing with a little more commen sense.

My $20 worth. -Chris P.S. goodluck with whatever you do and try not to kill yourself doing it. Ryan S. Well-Known Member yeah I would make it smaller, that rocket would almost be as tall as my mission impossible and it weighs around 32 lbs loaded. that is about a 10 foot rocket overall. build your other rockets and fly them, let this be a next summer project. I used to design rockets all the time and then I waited about a month and realized how stupid i was being, just wait it out. Neil Well-Known Member Originally posted by havoc821 I'm not trying to bash you but your way of doing things kinda makes me wonder. 1) Why do you "NEED" another 6" rocket? Can't you just enjoy what you have? Ok, so I do the same thing but I'm trying to not build more rockets and not end up flying them for another 6 months because I don't have the money for the motors. jus' cause. Yer a rocketeer, ya should understand that one. And I never said "need" if it was a matter of "need", I wouldent have built ANY rockets. I build rockets because I LIKE to build rockets. 2) Quote: It would be chopped into two 45" sections, fincan and payload. What is with you and HUGE payload bays. Something this size needs to be dual deploy. Even if it is only a few thousand feet, you will still be walking a long ways and risk losing it. If you meant that the payload bay was for dual deploy, you should specify because when I hear payload bay, I think of.....well.... a payload bay for lofting eggs, altimeters, bugs, etc. Uh... Duh.... The tubes only come in 48" lenths. If you saw the rsim you would understand better... But the internet on the computer the rsim is on is down, so I cant post it. The "payload" bay is going to be filled with a drouge chute and a main chute, plus electronics. don' worry, I aint THAT stupid... Of course something this size needs dual deploy. What do you think I am going to do, ask AMW to put ejection charges on thier motors? 3) Quote:Rsim says itll be about 18# dry... Thats pretty scary (a single J350 wont lift it over 1K... You need to learn the very important thing call THRUST to WEIGHT ratios. It is a good rule of thumb (or law) that you should have at least 5 times the "average" thrust as the weight of the rocket. 5:1, example, 1 lb rocket needs 5 lbs of average thrust. To see if you have enough thrust do this. Take motor's newtons Example, J350 and divide it by 4.448 to get the pounds of thrust and you get 78.6870503. That is how many pounds of thrust the J350 has. Now didvide that by the weight of the rocket and you get 4.371502794. That means you have a ~4.4:1 thrust to weight ratio. In other words, not good. You would need a LONG rail or rod to get this rocket moving in the right direction. When you run simulations you need to look at not only the altitude and velocity, but read the report thingy and look at velocity at launch guide departure and see if it is fast enough. Thats why I aint flyin' it on a J350... But heres a question for you (or anyone else who would know the awnser)... would it be safe to put J350s in the ouboards with nothing in the middle? The centers of the outboard motors are at least 3" apart, so I dont really know... A single J350 wont even go 1K... Ill say it again... I dont want to be playing around with 20# rockets and dual deployment at 1K. 4) If you can barely afford this rocket and it is made out of cheap stuff like sonotubes, you shouldn't be building it. If you can barely afford the parts how are you 1) going to afford the casings 2) afford the reloads ?????????? Uh... im gonna save my money like I always do... Isnt that what everyone does? I think you should get more experience in big L2 size rockets or any L2 rocket for that matter before you go crazy and building a big rocket each week. How many J,K,L flights have you done with rockets you designed yourself? Probably less than 3. I could be wrong. I like to dream about building big Porthos 2 size rockets all the time but dreaming and reality are 2 way diferent subjects. I could care less what you do but I'm just trying to get you off that one way street that only leads to your stubborness to accept others advice. No adult and especially not a 13 year old is capable of doing all these big projects within this much time that you have given yourself. You need to do one thing at a time, learn AS MUCH AS YOU CAN from it and move to the next thing. USE the stuff you learned and make use of it. Then see if you can learn anything else from the next rocket rather than flying through 4 rockets at a time and realize that you made the same mistake in all of them. I'm just trying to help, so sorry if I "bashed" to hard but you need to approach this L2 size rocket thing with a little more commen sense. I said it once, I said it twice, and now ill say it AGAIN! im finishing my other projects first. this is a WINTER PROJECT.Its SUMMER right now. Dont worry. My$200000000 worth.

-Chris

P.S. goodluck with whatever you do and try not to kill yourself doing it.
thats what everyone said about my BB guns... I still have both eyes.

I dont really want to make it shorter... I dont know how good I am at cutting phenolic tubes (do they cut well on a table saw?), so I think I will just use two standard-lenth tubes. I also like it the lenth it is... I dont like short rockets... They dont look right to me.

Neil

Well-Known Member
Originally posted by havoc821

I'm just trying to help, so sorry if I "bashed" to hard
well, if you cant defend your ideas, they cant be very good ideas now, can they?

Neil

Well-Known Member
Ill give it a few weeks...

But I really cant stand not building anything over the winter... There are no winter launches, so I can only build... It sucks... But I cant really go all winter without building anything...

Plus, I have the money to buy the tubes right now, so should I go for it any buy the tubing, or wait a bit longer to see if I come to my senses?

Ryan S.

Well-Known Member
just wait man, the tubes will be there, put the money in the bank, it will make more money for you. Then you can refine your building techniques.

Look at it this way. When people build motors, for example, they build small test motors, burn them, and see what the results are. Then they make then Ms and the Ns. They dont go straight to the Ms and the Ns because it is simpler cheaper and less time consuming to use small motors.

Now just think of that in terms of your rocket

Neil

Well-Known Member
Well, look at it this way... I have flown rockets on Hs four or five times, all successfull. I have rockets that can fly on Is, and I plan to do that very soon. I have rockets that can fly on Js, but I cant fly them untill next year for various reasons (my dad isnt certed yet, and after he does cert, there are no more launches to fly at), so if I just go up one impulse class at a time, itll be this time next year before I can build this thing... If it makes you feel better, ill make some more 4" diameter rockets (I dont have a problem with THAT! ) for practice on glassing etc, but I still wont be able to fly them till next year.

I guess ill just make a downscale version about 4" in diameter to keep me busy for a while... Then well see if I come to my senses.

daveyfire

Piled Higher and Deeper
Originally posted by Neil
If it makes you feel better, ill make some more 4" diameter rockets (I dont have a problem with THAT! ) for practice on glassing etc, but I still wont be able to fly them till next year.
Yes. I flew lots of Hs and Is before I flew a J, and lots of Js and Ks before I flew an L. Get LOTS of practice at each power level before moving up... since the power doubles every time, forces double and all sorts of stuff starts to go wrong. Gain competence at every level... even a "pseudo-cert" process may be a wise course of action. I'm not bashing your skills, but just because you've flown an H doesn't mean you can successfully fly an L powered rocket, and if it can fit an L motor, it's an L powered rocket!

Wow, this sounds incredibly familiar...

Neil

Well-Known Member
They only make two 54MM Ls that I know of... Or, at least, two 54MM Ls in the Rsim database... L1500 and L3000 is all I can find in there... I havent reall looked at the L motors much, though. K power is more what I am looking at for this rocket...

Is it OK if I make the smaller version of the Thunder Bird only 10" shorter than my origional plan? just 4" diameter, with a single 54MM motor mount... About 20" longer than the S&F... I dont want to make another rocket that looks just like the S&F, so itll be a little longer...

Aw, what the heck... Ill make one slightly longer and one slightly shorter.... Ive got all winter to do this, so I may as well a lot of them... If I cant start on anything bigger untill next year, Ive gotta do SOMETHING to keep myself busy, even if I dont fly them all for another year and a half... Now if only we would get that lathe... I could start making nose cones...

Maybe ill make a Fat Boy upscale as well... Much can be made with 10 mailing tubes....

Ryan S.

Well-Known Member
I hate to keep harping on you, but I would build something really nice, take alot of time on it, and fly it alot. remember, quality not quantity. Build a nice bird, get a nice finish, make the inside look nice, wire the electronics well. Make a rocket that is prestine and flies well. A workhorse bird.

Neil

Well-Known Member
My point is, I cant make several like that in a 4-6 month period... Ive got all winter, I can make as many rockets as I like... Finish one, start the next, finish that one... I bet I could make 4 or 5 "workhorse" rockets over the winter, if we ever get some good insulation in my workshop... Plus this fall, I can make one or two...

You underestimate the power of boredom. When boredom is combined with mailing tubes and plywood....

Boredom+paper tubing+plywood+jigsaw+lathe+foam+6 months=rockets. Lots, and lots of rockets. In many sizes. 1.5", 2", 3", 4"....

Class dismissed.

daveyfire

Piled Higher and Deeper
Originally posted by Neil
My point is, I cant make several like that in a 4-6 month period... Ive got all winter, I can make as many rockets as I like... Finish one, start the next, finish that one...
I dare ya.

Seriously, Neil, take it one rocket at a time. A rocket isn't finished until it's got everything installed... and I mean everything. When it's on the pad, altimeter beeping, igniter installed, and you walk away, THEN the rocket is finished. Lots of little issues crop up when you get it ready for flight, and these issues multiply with the size and complexity of your vehicle. Try one. Then build another using what you learned. Your experience will become much more valuable this way.

Ryan S.

Well-Known Member
yeah man, you dont need all those rockets. It took me an hour and a half to prep my terrier and that was a simple prep job, as they get bigger there are more things to prep and you will only get maybe 2 flights in a day

Smokin' Rockets

Well-Known Member
Originally posted by Neil

Is it OK if I make the smaller version of the Thunder Bird only 10" shorter than my origional plan? just 4" diameter, with a single 54MM motor mount... About 20" longer than the S&F... I dont want to make another rocket that looks just like the S&F, so itll be a little longer...

Why not try some electronic deployment? Try a two stage or clustering with air starts? There's alot you can do with a 4" tube.

......Bill