Soyuz 1/25... why not ?

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Hi Daddy!!
I explain you my technique.
I prepare a sort of mold made with 3 or 4 cones done with light paper.
Same shape like the final one.
View attachment 490589
These cones are easy to make since the normal paper bends easily.

View attachment 490591

Then i put the cones one inside the others.

View attachment 490592
So the "mold" is done.

The final cone (thick paper) is pre-bended with the steam iron. Here below the tools used. (Not high tech... but they work. )

View attachment 490596

So the final cone is pre-bended and then inserted in the mold.

View attachment 490598

Then with the steam blowed in the cone inside, the paper gets the final shape.

View attachment 490600

Then, the cone is glued having as reference the printed lines. Since the cone is bended to the final shape, it keeps the position without particular effort.

Thank you so much for sharing how you did this with such great detail! Great technique!

This was a really amazing flight / build... Totally incredible. I love the look of that rocket but those cones looked to hard to build so I moved on to more cylindrical models...
 
Here the continuation of the boosters workView attachment 401573
After the bonding of the paper cone, the booster is filled with foam.
You see a column of engines cases , here the explanation. Klima engines have a quite strong ejection charge. The behaviour is quite explosive. Normal tubes cant resist for long. I had problems after 3 flights. Not having thicker 18mm tubes I used a series of cases bonded inside a BT-20 tube.
This tube is necessary to bring the gases from the engine to the side of the tube where is located the parachute without pressurizing the slots of the fins. ( You can see the drawing I posted some messages before)
Hi PieroAcme.. What kind of foam did you use to fill the paper cone? I want to try this out on the model that I am building. I was thinking of using the spray foam in a can that you can buy at the hardware store, but I read that this will not work. Do you know if this is true? Paul
 
Hi Graf, yes you have to be carefull in the foam selection. "normal" foam you buy at the hardware store are in most of the cases not ok. The main issue is the tendency to shrink after the expansion. You need to select a "no shrinking" foam. I tested several types. The best I found is this one. Fischer PU 1K 750 . Test done with bi component foam from known brands were not so good. The problem is that time from mixing to expansion is too short and the way to insert it is not easy, then, if you dont respect the mix% to gram level you'll get shrinking effect even worse that normal foams.
 
Some time has passed from last post... almost 19 months.
And now finally time to launch !
Soyuz2 had to wait for long time. But there coudn't have been better contitions for the launch. The launch has been held in Molinella Airfield (Bologna Italy) in occasion of MIR2021, the yearly event of international launches in Italy. Perfect weather condition. Blue sky, low wind and launch spectators.
This project is my biggest model ever built. 1,9m height 4,2Kg , 20engines at 1st stage+ Boosters, 7 engines in the second stages, 540Ns total impulse.
During the lock-down I did some tests for the ignition system and the result was ok. But when you are at the day of the launch you still feel a bit nervous.
The first day at the field was spent to prepare for launch the day after. The work to be made is like to prepare 6 different rockets. Motor assembly, parachute packing and loading, 2nd stage ingnition system setup, booster and 1st stage assembly on second stage, boosters and 1st stage ingnition system setup. Then the launch pad adjustments for the proper holding the rocket. All done step by step and doing double checks.

Here some pics taken during the preparation

View attachment 484713
This is the 2nd stage ignition system. It is a tape with some BP that connects the engine ignitors.
View attachment 484714
Here the one for 1st stage and clusters
View attachment 484715

Hey PieroAcme, I so love this build! Can you help me understand the ignition mechanism shown here? How many igniters is this?
 
Hey PieroAcme, I so love this build! Can you help me understand the ignition mechanism shown here? How many igniters is this?
Hallo Switch! Sorry for late reply , but I was in a business trip , I'm back now.
What I use is the Klima cluster ignition system that consist in "tapematch" and fast fuse.
This is very simple and effective system for BP engines cluster ignition.
It is also easy to make by yourself. I explain you how.
IMG_20220423_131742.jpg
What you see above is all what you need , BP, Scotch tape.. and spaghetti.
Why spaghetti ? This is not because I'm Italian and we like spaghetti. But some technical characteristics are usefull for our purpose.
They are straight and the diameter is quite precise and you find several sizes of them.
Spaghetti will be usefull for the fast fuse.

You have to attach the tape to the spaghetti as below pic
IMG_20220423_131931.jpg

Then put some bp on the sticky side as below

IMG_20220423_132232.jpg

Then you roll the tape on the spaghetti.
Depending the type on engine you want to match you will have to select the right spaghetti diameter.
An Estes D will require a bigger spaghetti size than a C.

IMG_20220423_132342.jpg

Then simply cut it by breaking the spaghetti. Here below how it looks when it is inserted into the engine nozzle

IMG_20220423_132514.jpg

Every engine in the cluster needs the fast fuse plugged in
 
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The connection between them it is made with scotch tape with some BP in the middle.

IMG_20220423_132636.jpg

You will have to use an electric ignitor to light the tape. The flame will move along this one very fast and light each fast fuse.
It will important to consider the distances from the ignition point. This last one will have to be baricentric respect the engine positions.
 
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I'm sorry to re-awaken an old thread, but HOLY COW. This was an incredible build and an amazing flight. I especially enjoyed learning about how you ignited all the engines nearly simultaneously. I found your thread because I was researching ways to separate large powered side boosters (about 60cm long BT-80 tubes). If you launch this again, I really hope you post more launch videos! It would be especially cool to see the Korolev Cross from a camera mounted to the upper stage, wouldn't it?
 
Piero, that really is amazing. I'd have never guess that you could light 20 engines at once using such a system. The combustion must be incredibly fast, and uniform as well! It would be really interesting to have some high speed video of that ignition sequence. I suppose the center 4 motors ignite first, then as the tape burns to the outer engines, the mechanical connection from the center is severed, avoiding any tendency for the center motors' blast to pull the outboard igniters out?
 
I'm sorry to re-awaken an old thread, but HOLY COW. This was an incredible build and an amazing flight. I especially enjoyed learning about how you ignited all the engines nearly simultaneously. I found your thread because I was researching ways to separate large powered side boosters (about 60cm long BT-80 tubes). If you launch this again, I really hope you post more launch videos! It would be especially cool to see the Korolev Cross from a camera mounted to the upper stage, wouldn't it?
Thanks Nova ! Yes , your request is welcome, new videos will come including the onboard ;-)
 
Piero, that really is amazing. I'd have never guess that you could light 20 engines at once using such a system. The combustion must be incredibly fast, and uniform as well! It would be really interesting to have some high speed video of that ignition sequence. I suppose the center 4 motors ignite first, then as the tape burns to the outer engines, the mechanical connection from the center is severed, avoiding any tendency for the center motors' blast to pull the outboard igniters out?
Hi Tom, yes it is correct the center motor ignite first, the booster around 0,15 seconds after. This is made on purpose. The ignition of the center first helps the booster retaining system at lift off. The outboard igniters are secured by interference with the nozzles. These are very light and these will not fall off because of acceleration. About speed to light , yes, it is very fast. But not so uniform like the spider systems that I often use. The spider lights all engines at same time. But in this case was too big and I decided for this BP tape solution. The other point is that spider has also the tendency to give a bump to the rocket and this is must be avoided.
 
Hi Tom, yes it is correct the center motor ignite first, the booster around 0,15 seconds after. This is made on purpose. The ignition of the center first helps the booster retaining system at lift off. The outboard igniters are secured by interference with the nozzles. These are very light and these will not fall off because of acceleration. About speed to light , yes, it is very fast. But not so uniform like the spider systems that I often use. The spider lights all engines at same time. But in this case was too big and I decided for this BP tape solution. The other point is that spider has also the tendency to give a bump to the rocket and this is must be avoided.
Thank you. That you could make such a system work that consistently is amazing.
 
I know that I am super late to the party but, the Soyuz is my favorite rocket of all time (it makes the space shuttle look like a piece of junk in my opinion).
 
Beautiful video! The slow motion made it almost like an actual Soyuz launch! I'm still amazed that you can get all those motors lit, the boosters separated, and the laundry all hung out as it should be. Wonderful rocket!
 
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