The Shadow and Flame

[Neil]

Well, here it is. My first spring project. The "shadow and Flame".

The rocket will be 4" in diameter, 84" long, and it will weigh 8-12 pounds. It will recover on dual 56" chutes, which will bring it down about 16FPS.

The actual rocket costs next to nothing. All the parts are leftovers from my dad's L2 project. The biggest cost is the shockcord.

I have tried to post a thread on this thing 3 times so far, and every time I ran into a problem and the computer ate it, so this is my 4th time writing this...:kill:

It will fly on Is and Js, and possibly a K next year or the year after that. The tube will not be glassed, I think it is strong enough the way it is. The tube/fin joint will be glassed, though.

The MMT will be 54MM, so I dont get any ideas invlovling Baby Ms.

Ill attatch some pics of my progress in the next post. I dont want to loose the thread again!

I will proabably have this thing set up for electronics, with a PVC pipe in the nosecone to hold em. It will also be possible to use motor ejection if the motor i am using has it. I am going to buy a used Pratt ECS2B ground controll system thingy for backup to my RCC2X altimeter. I might buy a MAD apogee detector to use instead of the altimeter, I am not sure. Proabably the altimeter, though.

This rocket will be ready to go by LDRS at the latest, and it will definetly fly there.

Someone requested a "carl tulanko style photo album" for my big project, and I will try to deliver.

 

[Neil]

OK. It worked. heres some pics

Heres the faraway pic of the entire 12X48" sheet of plywood, with 4 fins, 3 CRs and a bulkhead on it. I will make my dad's CRs with the scraps. Priorities priorities

Actually I want to get used to making the parts before I make his. Honest!

 

[Neil]

OK. That wasnt the greatest pic in the world. these are better, though!

Heres some fins and some CRs for ya!

 

[Neil]

Whoops... I forgot one important bit that was in the first 3 tries at this post, but not in the fourth.

The Industrial Arts classroom has four jigsaws, a drill press, a drum sander, a belt sander, and lots of other great tools at my disposal. Thats where I am going to cut out all these parts.

heres the three CRs.

 

[Neil]

BTW, the marks on one of the centering rings is the motor retention system holes. I am going to put some screws, hex nuts and a few other parts in there to make a decent motor retention system. I cant afford another Slimline....

 

[Neil]

I have marked the tube for slotting, and I will proabably cut the slots tonight or tomorrow. First I have to find my new blades for my knife... Pics as soon as the slots are cut!

 

[Ryan S.]

sounds cool, where did you get the plywood and what kind is it?

 

[Neil]

another thing that was in my first three tries and not the fourth :kill:

I got it from a local RC airplane/rockets/model train store. they had a HUGE selection of plywood, for not-so-bad prices. I think its like $10 or something for a 12" by 24" sheet of 1/8" 5-ply aircraft birch plywood. we got two sheets of 12" by 48" by 1/4" 5 ply aicraft birch plywood for this rocket. Its good stuff! They usually are not too warped. Its the strongest stuff I have ever used (well duh, its the biggest rocket I have ever made, it better be tough! ). If you need some, give the word and Ill get some and tradja for an H128 or something for drag racin V2s

The kind im using for this one is a 12" wide by 48" long by 1/4" thick 5-ply aircraft grade plywood. its good stuff! It costs about $15-$18 if I remember correctly. Im not sure what the exact price is... Ill see if I can find the sticker on it later... That tells the price.

 

[Ryan S.]

I found some at the Home Depot....I wish I had used it for the bulkheads in my MI but o well, I think it will be fine.

I am not trading an H128 for wood!!!!

 

[Neil]

But this is good wood....

Well then, what DO you want for an H128 for a drag race?

Home Depot... You can get aircraft plywood at home depot? Evil grin....

 

[Neil]

Well, I slotted the tube yesterday. It came out pretty well, if I do say so myself

Theres still a considerable amount of paper hanging through the slots, but its not connected to the other side, so its fine. I will take care of it with an exacto knife later.

The tube is still suprisingly strong, even where I cut it. I expected it to be kind of flimsy, but its fine.

The slots look straight to me.... and all where they are supposed to be. I slipped with the knife once, so there is a little bit where I took too much of the tube out, but that will be easy to correct.

Heres some pics! This one is just a pic of the tube standing up.

 

[Neil]

And heres one looking down the tube. As you can see, theres still a lot of paper in ther... Not the end of the world, however. Ill take care of it later with an exacto knife.

 

[Neil]

I just went to the hardware store and bought a U bolt and a quick link. I decided to get the stainless steel quick link instead of the zinc one, because it has a higher strenth rating. The one I got can hold about 1125 pounds, but the zinc one can only hold 660 pounds. It cost a dollar or two more, but hey. Did I make the right choice?

The U bolt is 5/16" stainless steel. I dont know what it is rated at, but it looks pretty tough Is 5/16 a good size?

 

[thomasrau]

Neil,

Stainless was the right choice and those sizes are more than enough for your needs. You were right to spend the couple of extra buck and get the better quality hardware, having the links fail at deployment would ruin your day, especially if the debris hit someone.

 

[Neil]

Thats good to know... More than enough is good, if you ask me. Better too much than too little. Besides, it doesent add that much weight anyway

Yes, it would ruin my day, and proabably whover got hit by its day.:kill:

 

[Neil]

Well, tomorrow all the parts will be cut out, or in the process of being cut out. I have the plywood in the IA classroom, and I will proabably get a chance to work on it either tomorrow or Friday. Ill post pics as soon as I take em

 

[havoc821]

You paid $10 for 1 sheet of 1/8"x12"x24" 5 ply craft plywood!?! You got ripped big time. I got the same stuff from the local Michael's store and it was only ~$4-5 and then I bought it with a 40% off coupon and got it for like $2! Anyways your rocket sound neat, but I would not mount electronics in a PVC pipe tube at all and especially not in the nosecone. First off, PVC is plastic; plastic can get all staticy; static means zapped electronics. You don't want to risk a $100 altimeter do you? Didn't think so. Second off, mounting an altimeter in the nosecone means that you will have the vent holes (static ports) very close to the nosecone. Bad idea. All of the turbulent air coming over the nosecone right next to a vent hole is a bad idea because it will screw up you readings on your altimeter and that means early/late/no ejection. You will need at least 4"-6" below the nosecone/transitions/ or anything that causes a change in the flow of air to drill the vent holes. Well, that's what I have been taught. I could be wrong but I don't think I am. Anways, keep us posted with pictures!

 

[Neil]

:kill: OK.... I got a bone to pick with Ray and robins...:kill: Ill have to go to Michaels next time... Unless the stuff at Michales is infirior in quality, im not buyin no plywood from ray and robins no more.... :kill:

Yeah, the PVC pipe in the nosecone idea went bye-bye. at least for the altimeter, if I use one. I went to a carpet store and got a lot of tubing that will be the perfect size to fit inside the 4" tubing I am using for the rocket. the tubing (which I got for free ) isnt good enough for an actual rocket, but its the perfect size for a coupler or electronics bay or whatnot. I might buy a LOC electronics bay, but it wouldent fit right in the tube.

If I actually were to put something in the nosecone it would be a MAD, and that doesent require vent holes at all. PVC pipe is tough stuff. I think it would hold a piece of electronics pretty well.... I might want to test it out with something else first though. I wont be using it with my altimeter, though. Just a MAD or something that doesent require vent holes.

And I will proabably be getting a ground-based deployment system. A used Pratt ECS2B I think... I just press the button and it pops. So a PVC pipe, being very strong, and inexpensive, might be a good thing to hold a reciever, and also the transmitter thingy. My dad's buisness uses these long range transmitters to track turtles, and he is going to snag one for our rockets... I think it will be similar to the Waltson system, but im not sure. Either way, it just needs to be strong. PVC pipe is VERY strong, especially in the size I was thinking of using it... For this use (holding a transmitter and a reviecer), I think it will do fine. Im open to other ideas, though.

 

[daveyfire]

Putting ANY electronics in a piece of plastic pipe is a bad idea because of static charges. If you take a piece of fuzzy cloth and rub it all over the PVC, you'll feel static. Static is stored energy. When you put your altimeter into this stored energy thingy, the energy zaps out and destroys the ICs on the altimeter. That's bad I recommend you put the altimeter on a plywood or G10 "sled" inside of a piece of airframe tubing, either a coupler or some tubing to fit in the nose cone.

 

[Ryan S.]

This is true, and you can get the same strength out of a peice of FG tubing or just use carboard. IT isnt really a load bearing part

 

[Neil]

You know, I hadent thought of that.... Thanks for bringing it up....

I guess ill just use the tubing I got at that flooring store if I want to hold electronics....


Thanks for letting me know before I zapped my altimeter...

 

[Ryan S.]

why dont you put your altimeter in a tube coupler.

If you buy the loc electronics bay, then it would work as a tube coupler as well as an electronics bay

 

[Neil]

Whats the ID of the LOC tubing (4" size)? Mine is larger than the LOC tubing, 4" ID exactly, so it would require some tape or something to build it up to fit.

The Shadow and Flame doesent really have a payload bay... Though when I use altimeter based ejection, there will be a bulkhead assembly blocking off the motor tube, so then the whole thing will be a payload bay/parachute bay. I will proabably have enough room for an electronics bay, whether I decide to buy one or make one. I might modify the design to have a payload bay, or just have another tube that can be a payload bay if I want one. Say, 18" long or something. Just enough to hold electronics or whatnot. It will add weight, but if I want to add the payload bay, it will proabably be for a bigger motor, proabably with no motor ejection charge. Does the K550W have an ejection charge?

as I said earlier, I am getting a Pratt ECS2B, so I really just need space to put the reciever or whatever. Would a cardboard tube in the nosecone work? I dont think it needs vent holes, and if its cardboard it shouldent zap it... where do you think I should put the reciever?

And if I get a MAD, where should I put that? and in what? Just another cardboard tube with a sled, or something else?

As you can see, I dont have that much experience with altimeters/apogee detectors. I will be "practicing" dual deployment with my stretched Mustang this spring. I wont actually be using it for dual deployment, but I will have ematches or whatever in there, with no BP. I will proabably just use motor ejection. I dont need to risk my rocket (or altimeter) playing with dual deployment. if something went wrong and the ematch didnt fire, it wouldent hurt anything, as long as I had the motor based ejection. I might try a BP charge at apogee and an ematch with no BP at 300' or something, but I havent decided yet. I just want to get a feel for the altimeter before I put it in something for real.

 

[rocketkid88]

If you decide to use a ground based system that’s your choice, but if your rocket is going to be out of sight when it hits apogee how in the world are you going to know? also what about clouds? the sun? drifting smoke?
for redundancy ground based is maybe good.... but
other than that i think having an extra 18" payload bay for the electronics (what ever you use) is a good idea, for motor based ejection you can leave it out and for the 'bigger' plugged motors you can use either dual or single apogee deployment.
keep us updated... and pics?

 

[Neil]

Unless you want pics of u bolts.... THere hasnt been any progress since I cut the slots. I might cut the fins out tomorrow, but we are building balsa wood bridges in IA tomorrow, so its iffy. Though while the glue is drying next class (I will have the pieces for my bridge cut and ready to glue by then), I will have "free choice", meaning I can use flightsim or the woodworking workshop.... You can guess which.


You can usually tell when the thing hits apoggee... And dont most of the bigger motors (plugged ones) have smoke charges for tracking?

If its going to fly above the clouds, I really dont think its the best idea to fly at all. If the altimeter failed, and there was no deployment, you would have a missile streaking out of the clouds at you when you think its coming down on its chute. I dont think thats very safe.... Better to wait untill the next day, or at least untill the clouds clear.

I guess I will make a payload bay for the electronics... I could proabably start making it now. Ill have to make another bulkhead when I am cutting out the parts....

 

[Ryan S.]

first of all RocketKid is right, if your going to use a Radio controlled ejection it should be for redundancy only not your only means of deployment. He is also right that you are going to have a tough time seeing apogee unless your rocket is huge and has a nice smoke charge, it is/has neither.

secondly, what is the point of putting an altimeter with dual deployment in a rocket if you arent gonna use it. Wire up the ejection charges and use motor deployment as backup. Have a drogless deployment at apogee then have the main at like 500 ft, this way you can see if you screwed up or not, it isnt that hard not to and if it crashes.....your in trouble.

Dude, no big motors have ejection charges, if you put a K550 in this rocket you will definanlty lose it. You need at least dual deploment if you want to even think about getting it bacck.

Here is an idea; dont put so much crap in this rocket that way you arent approaching so many unknowns. Clearly you dont know what you are doing but you can learn if you go slowly then you dont need to risk your rocket or anything else for that matter

 

[rocketkid88]

well, i think mabye your going a little bit hard there Ryan... but that *is* what i was trying to say in not so harsh terms!
Neil, i think that you are going fine, but like Ryan said take a big breath and tackle this one step at a time. first off (and this is my advice only, mind you) don't bother with the altimiter bay at all for now. Build the rocket with a particular motor in mind that you know has motor based ejection. something that will fly it, but not out of site. After you have done this succesfully, you can start thinking about bigger mottors and altimiters. most likely if you build the alt bay now, by the time you want to use it you will wish you had done it different!!
hey, its not like your in a big race or anything. just have fun and stay on the earth!! (you can go to Marz latter... )
ah well, good luck!

 

[Neil]

Your missing the point, ryan... I dont know a lot about dual deployment, thats true, so I just want to test it out one step at a time. First of all, I just want to see if I can even wire the thing up right and get it to pop an Ematch. I dont want, or need, to put dual deployment on my Mustang for a flight on an F20. I just want to ease into the whole dual deployment thing, before I decide to use it in my Shadow and Flame. I also dont have all that much money, so I dont want to waste it on ejection canisters for rockets that really dont need dual deployment. On the other hand, Modern High Power Rocketry has instructions on how to make a BP canister out of a coathanger, so I guess I could experiment with that... THeres not a launch for a month untill the next launch, so I have plenty of time to decide if I want BP or not.

Actually, "big motors" all the way up to the J570 have ejection charges. I just wanted to know because on Rsim it has delay options on the K550W, which confused me.

What would you guys think of having a MAD as primary drouge ejection, then the radio controll thing?

Whats the deal with AMW motors? Do they have smoke charges, or not? Is there a smoke charge on the AT K550? Im not going to be flying this on either of those motors untill next year, so I dont think I really need to worry about it all that much. all the motors I want to fly it on now have ejection charges, so I can use that to deploy the chute with the radio controller as backup.

Besides, this rocket is at least a month or two away from flying, and I havent decided exactly how I am going to deploy this thing. Either way, the rocket will only go 1777' with an I366 (one of the motors I want to fly it on this year), and that is within visual range. I have flown smaller rockets that high and seen apogee. And the I366 has an ejection charge, also, if I remember correctly.

Oh, and no need to be so harsh ryan.... The point of the Mustang and its BP-less Ematches is to GET me used to this whole altimeter thing. I dont see how slower I can go than that.... I mean, if I have 3 or 4 flights with the Mustang, have some bare ematches, some BP charges or whatever, I will proabably learn a lot about how to operate the thing, and it will get me ready to put it in "the big one".

Read back a few posts, and you will see quite clearly that you suggested that I do what I had just said I was going to do. In almost the same words, I might add.

 

[Ryan S.]

you dont need ejection canisters, just pour some BP in a plastic bag stick the ematch in there and tape it shut.

You wont know if the ematch popped rigght unless the rocket opens up. I am not trying to be harsh, I just think that you should use the BP, even if it doesnt work your rocket wont be damaged.

I would just use your altimeter and the PRATT.

I would be glad to help you at the next CMASS launch......

 

[daveyfire]

Originally posted by Neil
I dont want to waste it on ejection canisters for rockets that really dont need dual deployment...

Actually, "big motors" all the way up to the J570 have ejection charges. I just wanted to know because on Rsim it has delay options on the K550W

In the whole scheme of things, ejection charge canisters are CHEAP. If you can't afford to buy ejection canisters, you shouldn't be flying HPR, because there are SO MANY other little things that will bite you in the butt on the flying field. Testing is definitely needed, and so I wouldn't pinch pennies on the recovery system. Besides, a good rocketeer makes ejection charges out of pipette canisters and PVC fittings and plastic baggies and things like that

"Big motors" all the way up through 54mm have ejection charges. This includes the K550W and the K1100T, but not the K700W or the K1275R. However, the K550W and the K700W run at similar Kns and have a similar burn time, so I would imagine using a delay well on the K700W with a K550W delay and ejection charge would work well.

Smoke charges on 54mm motors are included, but they aren't that big, and trust me, when your rocket gets up 6000 feet, all the smoke that's dumping out of the nozzle quickly becomes too little smoke. I love full-diameter smoke, it's so pretty, but it also takes up room that could be used for propellant... quid pro quo...