Whiplash build thread

[blackbrandt]

Here is the build thread for my super-modified Estes Optima. This rocket will have a 29mm motor mount in both the booster and sustainer. The booster will house a AT G138, and the top stage will house either an H410 or an H399. This rocket will use Dual Deployment by a Raven3 altimeter. Before I get comments about how I am not allowed to use Electronics for any recovery or airstart purpose, I am getting a L3 flier to fly this rocket for me. The Raven will also control the airstart.


I started with the motor mount for the sustainer:
I cut out 4 rings of 3/16 inch ply (birch):

(Not sure if you can see it, but in the background, you should be able to see some of my attempts...


I now drill out the center with a 1 1/4 inch drill bit.




Then, I scuff up the motor mount tube with some 60 grit to improve adhesion. On the rear-most centering ring, I glued on a boss for the screw for the rail button, and also drilled two holes for the motor retention plate. This is glued on to the back of the motor tube.

I now check the spacing between that ring and the next ring up, because I want the fin to be glued to 2 centering rings and the motor mount tube.
Once that spacing is good, I glue on the next 3 rings. The top ring hold an eyebolt.

Here is the motor mount, minus the fins and the bottom centering ring. This was one of the dry fits, and I had some trouble with the bottom centering ring. But it is all good now.

Here are the fins, all cut and beveled:

Fins were beveled with this rig:

Here is the rig in action.

I also got the booster fins cut and filled:

I will get progress and pics tonight. Definitely.

Thanks for following!

 

[UPscaler]

Sooo...what're you planning on flying this on?

H399 to H410? :tongue:


Braden

 

[blackbrandt]

Maybe...

 

[aditat2]

And I thought my workbench was a mess - but then a clean desk is the sign of a sick mind.:eyeroll:

 

[UPscaler]

Maybe...

I wouldn't recommend that...If you're shooting for altitude you really should have a good kicking motor on the bottom, and stage it to a long, slow burning sustainer motor. While high altitude is fun, I can assure you there is one thing that will ruin your whole day...and that is the lack of a tracker.

That the situation in a lot of cases, no always high altitude. Had it not been for Manny's tracker in my Nike, It would have been a looonnnnnngggg day in the 103 temp looking for that thing!


At any rate, good luck with the flight!


Braden

 

[blackbrandt]

And I thought my workbench was a mess - but then a clean desk is the sign of a sick mind.:eyeroll:

Oh, yeah? This is the pic of my workbench:

I wouldn't recommend that...If you're shooting for altitude you really should have a good kicking motor on the bottom, and stage it to a long, slow burning sustainer motor. While high altitude is fun, I can assure you there is one thing that will ruin your whole day...and that is the lack of a tracker.

That the situation in a lot of cases, no always high altitude. Had it not been for Manny's tracker in my Nike, It would have been a looonnnnnngggg day in the 103 temp looking for that thing!


At any rate, good luck with the flight!


Braden

I may be borrowing a tracker for the flight, I'll have to see. If I can get a tracker, I am thinking a H399 to an H54...



I got some more progress. I laid up the fin fillets (internal) with wood glue.


I then attached the bulkhead plate to the back of the nose cone after lopping off the back:





Also got some progress on the booster. This is a 29mm 3-grain casing. Yes, I know it is a stubby motor mount. Because it is a stubby booster.
The cord is a kevlar cord glued to the motor tube and the centering ring.



May get more tonight, I have to see after I get back from church if I can get this greek homework done... :dark:

 

[T-Rex]

I got some more progress. I laid up the fin fillets (internal) with wood glue.

Um, it looks to me like you painted the fins (one orange and one black) before you poured those massive fillets. It usually is better to paint after all the gluing is done. I apologize if I am not seeing it correctly.

Terry

 

[3stoogesrocketry]

No he painted before glueing the fins. Also matt do you have a pictures of your interstage coupler? I am interested how you built yours.

 

[blackbrandt]

It is just a coupler glued into the lower stage. Nothing fancy.

Also, the reason I painted the fins before gluing is so I can get a better paint job. I am horrible at masking, so I figured this would work.

 

[blackbrandt]

So just 'cause I am OCD like that, I decided to fill up the 1/4 inch of nose cone not occupied with the bulkplate with glue:



Makes it look pretty...


Lemme get a pic of the interstage coupler, might be a few minutes. It is just a coupler glued into the booster stage...



Thanks for following!

 

[Aksrockets]

Gee, I hope those "fillets" dry before you launch it...

Alex

 

[blackbrandt]

Already dry. Actually had to bring it inside where it is 80 degrees instead of my workshop where it is 50...

 

[MasonH]

Thats what EPOXY is for.

 

[blackbrandt]

Why get epoxy if I have an abundance of strong wood glue? Besides, it is already dry!
Matt

 

[WillMarchant]

Why get epoxy if I have an abundance of strong wood glue? Besides, it is already dry!
Matt

Wood glue is an excellent choice for bonding wood and paper. I think it is a bad choice for bonding plastic nose cones to wood bulkheads.

 

[bill2654]

Does your mentor know your building it this way? WOOD glue? Are you kidding? Havent you learnd anything from some of this forums other build threads?

 

[Aksrockets]

Wood glue is stronger then epoxy for wood-paper joints. Paper to paint on the other hand...

Alex

 

[eggplant]

Wood glue is stronger then epoxy for wood-paper joints. Paper to paint on the other hand...

Alex

Or plastic to wood...

 

[3stoogesrocketry]

Can you please post a picture or two ? Id really like to see how the build is going.

 

[CarVac]

Wood glue is stronger then epoxy for wood-paper joints. Paper to paint on the other hand...

Alex

It's not better than Aeropoxy ES6209, which wicks into wood and paper in the way that cyanoacrylate does, making it incredibly strong.

 

[bill2654]

Any glue on paint is not good.

 

[blackbrandt]

OK all, sorry for any confusion this may have caused.

I glued the bulkplate into the nose cone with epoxy, and then filled up that void with wood glue. Sorry it it sounded different.

I roughed up the bottom edge and lower part of the fin with some 60 grit.

Bummer, file is too large to attach...
Lemme fix that...

 

[grouch]

I am going to attempt to provide a little constructive criticism here. You say you have a L3 to help you fly this thing, if I were you I would ask for his guidance with help building your project. Matt, you are in way over your head and you don't see it and that is dangerous. If you were close to me, I would help you with the build or at least show you a few construction techniques that will help you build more rockets in the future. You should really start with a decent mid-high power kit. There is no shame in building a kit, they teach you several techniques while limiting the areas you can fail. Trust me, you won't build it mistake free. Each time you will learn something that will help you later with more complex projects. Rocketry is a marathon not a sprit, there is no hurry to get to the level where you can successfully build the project you have planned but in my humble opinion you are not there yet. The kicker is, if you start slow and stay with it you will be there before you know it.

Electronics take a bit of careful planning and a lot of prep to fly. They are not a kick the tires and light the fire affair. I know you are borrowing an altimeter, are you prepared to replace it if your rocket fails? Are you prepared to repair or replace the rocket if it does drill a hole to China? Personally I was nervous as all get out on my first mid power flight. I was completely petrified on my L1 flight and I was pacing around like a prisoner on death row as my L2 ship sat on the pads. Each time there was something that could have gone wrong. Each time I did my level best to eliminate all possible points of failure. Each time I realized that there could have been a point of weakness I overlooked or did not consider. Each time I was successful due to that fear of failure. You seem to be lacking this fear. Believe it or not, I want to see you stay with the hobby. It is by far the most enjoyable hobby I have and I want you to know that feeling but it only comes with success. I am afraid you will fall short of your goals and put it up forever. Remember, a candle that burns twice as bright burns only half as long.

 

[rocketgeek101]

Could you post a pic of the whole thing dry fitted together?

 

[blackbrandt]

Sure...





Sorry it is upside down. The little white tube at the end is the booster stage.





Here is the motor retention system.












Here is how I get the booster fins all to the same shape. I used my beveling jig, and ran the fins across for about 5 minutes.
They look pretty!












And this is why I should be called captain overkill:

If you expand the photo, you can see the yellow 28 inch chute up in the top of the photo.
45 feet of kevlar cord.
Is this overkill? Right next to the hose spicket is the e-bay.





Oh, the book and bowl are my greek book and fruit bowl that my mom made me study and eat...

Thanks for following!

 

[3stoogesrocketry]

Wow , ok.




P.s. Duck and cover

 

[blackbrandt]

Why do you say that?

 

[Rocketbuilder]

At least it it gets stuck in a tree you'll get most of it back. That is a lot of Kevlar!

 

[blackbrandt]

That is actually the point, rocketbuilder...

 

[Quaranta]

That is actually the point, rocketbuilder...

What parts do you expect will still be connected to the shockcord after boost ends? :rofl: :wink: