Trident I missile build

What are you working on with 1/4 thick fins and weight isn't a problem? Must be fairly large.

Madison Alum said:

What are you working on with 1/4 thick fins and weight isn't a problem? Must be fairly large.

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Well you see ,I have an Loc plastic transition that goes from 4" to 3" ,so I figured I`d build this .......

Scaling will not be a problem ,as I have some .50 BMG rounds in the shop for measuremnts :wink:


Cheers

Paul t

sodmeister said:

Well you see ,I have an Loc plastic transition that goes from 4" to 3" ,so I figured I`d build this .......

Scaling will not be a problem ,as I have some .50 BMG rounds in the shop for measuremnts :wink:


Cheers

Paul t

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Paint the tip red and call it "Tracer"

That should be a nice looking rocket. Looking forward to seeing pictures.

Got a little done on the aerospike today. Still need to put some wraps on the center rod to get the telescoping look. Also, the length doesn't look quite right, so I may fool around with that a bit.
Also loaded the nose weight in to check the overall weight and CG vs predicted. Weight is looking OK but the CG is too far back, giving a margin of stability of about 0.94 with an I245 loaded. More weight needed. This thing is turning into a wallowing pig for sure.

Added the nose weight with a cross dowel and epoxy to hopefully hold it all together. Final weight, prior to painting is 2737 gms unloaded, with a margin of stability of 1.15 with an AT I245 in it. So it should fly OK.
I am getting ready to do some ground testing, as 1140 grams of the weight is in the nose and I want to be sure the chute comes out, other than when it hits the ground and splatters all over the place. I haven't done any dual deploy so I have none of the equipment for that, but I was planning on just loading up my 38mm reload casing with about 3gms of powder, and using a Quest igniter to light it off. Should this work alright, or should I go a different route?

Another question I had was in regards to the aerospike. It doesn't seem to have any effect in the Rocksim simulations. I know it is on the real missile for better aerodynamics, but I am not sure if it will have any adverse stability effects, similar to the boattail. Any info on this would be appreciated.

Have a safe holidays.

Your rocket does not go fast enough for the aerospike to have much effect. You would need to push it through the sound barrier.

Thanks. I knew it was on there to give it longer range, but wasn't sure about how exactly or under what conditions it had the effect and what other effects it might have.

Made a little more progress. Worked on the nose cone fit and also the boattail/nozzle set up. Couldn't find any good cardstock in town and we've been hit with a big enough storm to keep me at home, so I used a few layers of printer paper glued together. Didn't remember to reduce the diameter of on the input to Payloadbays transition program for the inside layers and never got past kindergarten in cutting with scissors skills but all in all, it came out OK. I figure they will have to be replaced or have some major repair work after each launch as a paper transition on the aft end of a 3-4 pound body isn't going to like the landing. The picture makes the nosecone look like it overhangs the bodytube some. enough that I went back and checked to convince myself that indeed, it was centered. Next step is to quit procrastinating and ground test the thing before I have to go back to work. Then if we get a not too cold day, shoot it with some primer.

You’ve got to love the euphemism they used with regards to the warhead bus “Equipment Section”; because everybody has “Equipment” consisting of a half dozen or so independently targeted nuclear warheads lying around in their garage or shop.

I know I do.

Well I hope you have better luck building this model than the DoD has had in attempting to retro-engineer “Fogbank”.

Finally got the ground test off today and it was a success. Hardest part was getting the ignitor set up in the casing, as the leads weren't long enough to extend out the end of the casing and I didn't have any wire laying around. So I ran the aft closure and the base of the engine retainer over the leads of my Quest launch controller, taped everything up so it wouldn't short out inside of the casing, added the BP (only used 1.4 gms, standard AT load), screwed everything together, set the rocket up in the back yard, chased my dog back into the house (she was bound and determined to be in charge of the hole thing, since it was her backyard), fired up the camera and voila! Nose cone shot out dragging the chute, nomex and shock cord with it.
Now, as another first for me, I will try to figure out how to post the exciting 3 second film of the event on here. But not tonight.

Well, here is the video. Not much to see, but a learning experience for me. Have been looking into a full body decal for this, as I don't think I can even come close to making it look like the real thing. Other than putting on a coat of primer and adding the decal, don't see anything more happening until next April.

https://youtu.be/N0t1jlEpUGg

Nice and a success ! Your build turned out very nice ,and it`s different...I like that ! Looks like you`re in the same boat as me ,lots of snow and too cold to paint, man i hate that.

Have you decided on the finished pattern ? Have you thought of doing a basecoat then using trim MonoKote ?

Did you post a color scheme for this project ?

Paul T

Thanks,
I've been working with Mark at Stickershock to get a wrap made to match up with the missile in my avatar. You can see a much better view at https://www.usnavymuseum.org/centralhall.asp.
Still need to get a more telescoping look to the aerospike.
And yes we have snow here. I think we have more snow so far this year than we did all of last year. Though we do need to make up for a big lack of water from last summer. The plant where I work has been shut down over Christmas, so driving has not been a hassle yet.

I can see now the challenge of getting those colors right ,looks like chromes and copper.


Paul T

Hello friend ,just wondering how this project was comming along ?

Hope you didn`t forget !


Cheers

Paul t

I haven't forgotten yet. Have a wrap coming from Stickershock for the body. Still need to prime and paint the nosecone. Also, get the aerospike to look more realistic. May have to put it in my dremel chuck and try to shape it with a file. I've got plenty of rod to break trying to get something that looks good. Supposed to be in the 60s here tomorrow, but raining. Then back down into the 20s on Thursday. Although, I imagine that's a few degrees warmer than what you are experiencing. In the mean time, I have a North Coast SA-14 in the works and a Fliskits Long Overdue behind that.
Are you still looking at making the bullet? I see you have a few other projects in the works, as well.
John

Madison Alum said:

I haven't forgotten yet. Have a wrap coming from Stickershock for the body. Still need to prime and paint the nosecone. Also, get the aerospike to look more realistic. May have to put it in my dremel chuck and try to shape it with a file. I've got plenty of rod to break trying to get something that looks good. Supposed to be in the 60s here tomorrow, but raining. Then back down into the 20s on Thursday. Although, I imagine that's a few degrees warmer than what you are experiencing. In the mean time, I have a North Coast SA-14 in the works and a Fliskits Long Overdue behind that.
Are you still looking at making the bullet? I see you have a few other projects in the works, as well.
John

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Yessir ,the 50 cal. is going to be done, soon I hope !


Paul T

The wrap from Stickershock came Thursday. It looks really cool. Thanks, Mark for you effort in coming up with a realistic skin for this missile. Pictures will be coming once it gets back to decent painting weather. With the way winter has been going so far, that may be in a couple of weeks. Will have to wait and see.

Madison Alum said:

The wrap from Stickershock came Thursday. It looks really cool. Thanks, Mark for you effort in coming up with a realistic skin for this missile. Pictures will be coming once it gets back to decent painting weather. With the way winter has been going so far, that may be in a couple of weeks. Will have to wait and see.

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Could you post a picture of the wraps please ? I`ll be your bestest friend ever !!!! (it`s worth a shot )LOL


Paul T

Here is a shot of the decals. The copper for the motors and then some silver/gray sections with the hatches, rivets, etc which won't really show up well until applied. Lighting is not so good, but picture taking is not my strong suit.

Madison Alum said:

Here is a shot of the decals. The copper for the motors and then some silver/gray sections with the hatches, rivets, etc which won't really show up well until applied. Lighting is not so good, but picture taking is not my strong suit.

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WOW ,is that ever cool or what !

The copper wrap looks awesome ,I didn`t know he could that !

I can get a pretty good idea of the hatches and rivets etc. throught the cover paper ,it`s going to look great !!

I can hardly wait to see it finished.

This is a great build ,I love it ,nice and different and very nice work !

Cheers

Paul t

Finally got some primer on the Trident I. Left the aerospike off, as I am still trying to get it to look more telescoped and to get it centered in the nose. I figure another round of primer then sand and decal application. I taped over all of the fins as I was not sure if the paper cover on the lexan would bleed through.

Tried to get the brown nose cap painted on today. Turned out looking like crap, so i got most of the paint wiped off while it was still wet, sanded the rest off after ti dried and repainted it white. Try again later. I guess the initial launch will be pushed back to ROCI's june launch, assuming i'm not working.

Madison Alum said:

Tried to get the brown nose cap painted on today. Turned out looking like crap, so i got most of the paint wiped off while it was still wet, sanded the rest off after ti dried and repainted it white. Try again later. I guess the initial launch will be pushed back to ROCI's june launch, assuming i'm not working.

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What happen? Is it only the tip that needs to be brown ?

At any rate ,I think we`ve all been there, and it sucks.

Last fall ,nearing the painting season ,I tried to rush my TLP MIM HAWK 23 and the tan paint for the body (Rustoleum 2x) ran and sagged while drying.I did not notice until the next morning......I was pretty pissed

I guess the paint has had long enough to cure and harden, so I need to get outside one day and sand the whole thing down and repaint.

Yessir ,happens to everybody :wink:

Take care

Paul T

Didn't get a good seal on the mask and the paint ran under it. Just the tip of the nosecone is brown. The tip comes off to attach a lifting fixture when loading/unloading the missle. With it off, you get to look in at the warheads, at least the tips of them.

Madison Alum said:

Thanks. I knew it was on there to give it longer range, but wasn't sure about how exactly or under what conditions it had the effect and what other effects it might have.

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Has to do with supersonic shock waves and aerodynamics...

When the missile is subsonic, the flattened, rounded nosecone shape is actually the most efficient, even for breaking out of the water. Just like with model rockets, the rounded "Big Bertha" nose cone shape is actually very efficient from an aerodynamics standpoint. In addition, the larger, rounded, bulbous nosecone has more space inside it than a sleeker, pointier nosecone would have for the same length. More room for more RV's...

As the missile accelerates past the sound barrier, the rounded flattened nosecone becomes VERY inefficient-- at those supersonic speeds, the long, slender cone shape is more efficient. Thing is, we can trick the airflow into behaving as if the nosecone were long and slender-- which is the most efficient shape for supersonic flight. By extending an aerospike, which "trips" the airflow and sets up a conical shock wave from the tip of the aerospike back toward the outer diameter of the nosecone. This shock wave has supersonic airflow ahead of it, and the airflow behind it is subsonic-- the shock wave marks the transition from supersonic to subsonic airflow. Basically, the area under the aerospike to the surface of the nosecone inside the shock wave is stagnant airflow... to the supersonic airflow surrounding the missile, it flows along the shock wave from the aerospike and past the rocket body along the various shock waves set up by the missile's body as it passes through the atmosphere, thus reducing aerodynamic drag, increasing range...

This is the same basic reason that high speed jets use various intake designs, from moveable cones or half-cones on various jets like the Mig-21 to the F-105 Starfighter, to moveable fence air intakes like those on the F-4 Phantom, to "drooping ramps" like those on the F-15... These modify the shock waves to "trip" the supersonic airflow to subsonic, so that only subsonic air reaches the compressor face, as the compressors in the jet engine aren't designed to handle supersonic airflow...

Later! OL JR

This shock wave has supersonic airflow ahead of it, and the airflow behind it is subsonic-- the shock wave marks the transition from supersonic to subsonic airflow

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Not necessarily. The situation can be more complicated than this. Only a normal shock will have subsonic flow behind the shock wave. Conical shocks or 2-D oblique shocks still have supersonic flow behind the shock, but the Mach number is lower. Conical shocks or oblique shocks are weak shocks compared to normal shocks especially at high Mach numbers. Intakes on supersonic jet engines are a good example, because the strategy is to minimize the loss in total pressure. An oblique shock on a jet engine intake can be a good compromise on lowering the loss of total (or stagnation) pressure. Many games can be played on supersonic jet intakes in order to keep total pressure losses to a minimum.

It is right that the blunt trident nose cone is good for fluid (water) flow and subsonic flow and not good for supersonic flow. The Trident nose cone is so blunt that if it did not have the aerospike a strong detached shock would form in front of the main body, because the supersonic flow would not be able to negotiate such a quick turn. Such detached shocks are normal at the front and tend to bend around the body. The loss in total pressure is very large at the front and the corresponding rise in static pressure is very substantial. The idea of this aerospike is to get a conical shock formed ahead of the main body and reduce the loss in total pressure. At the same time the lower Mach number behind the conical shock (even though still supersonic) has more room to flow around the blunt body and manage the static pressure rise.

If you want to continue the discussion of intakes, (this is really a digression) an interesting example are scram-jet vehicles. In essence a oblique shock is started at the leading edge and the body contour on the underside actually decelerates the supersonic flow to the scram-jet intake. In doing so the total pressure losses are kept to a minimum along with assuring a high static pressure rise to the scram-jet intake and at the same time creating lift on the body contour.

After much procrastination, I started applying the wraps and decals from Stickershock. Got the big copper colored wraps on. Had to put a few slits in the top where the body necks down at the top of the second stage. Next is applying the interstage and transition decals.

Your efforts have paid off. Very good looking rocket!