Soyuz build from Cosmodrome Vostok

jazzviper1 said:

I had the same wrinkeling problem on Apogee Saturn 1B and on th bottom third of my Centuri Thunder Roc.

That aside this is one awesome build you have going. I am verey impressed and a little jelous of you skill.

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....had the eact same problem last year with my Sheris HR - Gemini Titan. Never had problems with the old Krylon.

Repainted orange areas after sanding rough spots. Paint went on smoothly this time.

Later removed masking tape strips located at core to booster bond points.

These were placed before all painting started. Their removal exposes clean bare fiberglass surfaces for strong bonding.

Used fiberglass drywall joint tape to create a grid effect for the grid fins.

Cut the tape in rectangles with the weave on a diagonal and stuck it to the fins. Then painted that rocket section with another buildup of white paint.

Brush painted escape tower motor nozzles with dark red acrylic.

Masked off shaft below nozzles, but was not able to mask paint lines due to the small size of the features.

Masked two upper core rocket sections and painted areas green.

Then loosely fitted upper rocket together to see how it looked.

Rocket painting is all done!

This is one of many pictures I am using to select paint color and locations:

https://rpmedia.ask.com/ts?u=/wikip..._TMA-3_launch.jpg/79px-Soyuz_TMA-3_launch.jpg

delta22 said:

Used fiberglass drywall joint tape to create a grid effect for the grid fins.

Cut the tape in rectangles with the weave on a diagonal and stuck it to the fins. Then painted that rocket section with another buildup of white paint.

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Genius....pure genius ! I will indeed have to steal that idea (but I`ll give you full credit + royalties )

I`m licking my chops everytime I look at your build ,then swivel my chair 180° and stare at my Vostok box sitting in the hobby room corner !

Lovely work !

Paul T

delta22 said:

Used fiberglass drywall joint tape to create a grid effect for the grid fins.

Cut the tape in rectangles with the weave on a diagonal and stuck it to the fins. Then painted that rocket section with another buildup of white paint.

Click to expand...

Now THAT is a great idea ... would have never thought of it! Thanks, and keep those build tips coming!

Amazing build, but im curious, why didnt you use a more 'flat paint'? I know alot of scale builders dont like the shine. I try and use low or semi gloss paint if flat isnt available.

just wondering!

Ben

ben_ullman said:

Amazing build, but im curious, why didnt you use a more 'flat paint'? I know alot of scale builders dont like the shine. I try and use low or semi gloss paint if flat isnt available.

just wondering!

Ben

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My guess is, probably because of the decals. Waterslide decals do not like flat paint.

It's better to apply them over glossy paint then a light spray of Testors Dullcoat or Future with talcum powder mixed in for a flat clear topcoat.

beautiful modeling! hope the flight goes well

sandman said:

My guess is, probably because of the decals. Waterslide decals do not like flat paint.

It's better to apply them over glossy paint then a light spray of Testors Dullcoat or Future with talcum powder mixed in for a flat clear topcoat.

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learn something new everyday, didnt even think about that.

thanks!

Ben

Boris,

That is a beautiful job. Only 1 more week and I can see this in person.

Great idea for the grid fins.

I'm looking forward to seeing the launch. I'll see if I can remember to bring my camera this time.

Looking forward to launching in 6 more days at the 4/30/11 CMASS Amesbury, MA launch.

Glad you gentlemen are enjoying the thread.

ben_ullman said:

Amazing build, but im curious, why didnt you use a more 'flat paint'? I know alot of scale builders dont like the shine. I try and use low or semi gloss paint if flat isnt available.

just wondering!

Ben

Click to expand...

Gloss paint is much easier to clean than flat paint is. Rocket grime never seems to come off flat paint.

Picked up some stainless steel tape from JC Whitney.

With repeated scoring it can be cut with an Exacto blade, but blades must be replaced frequently. Used 5 blades to cut 5 pieces.

Did a stainless wrap of the bottom 3/4" of the central core.

Also inside near bottom of each booster.

Used fingers to work tape down flat, then end of popcicle stick to firmly work edges flat and slightly into paint surface.

Had to be careful of sharp edges and burrs working with this. Also to avoid crimping tape by bending too much.

What motors do you plan to fly it on for its first flight?

To minimize damage to the escape tower when the recovering rocket contacts the ground, will allow the escape tower to separate from the nose cone during recovery.

Used a similar approach when I had the privilege of flying Carl Tulanko's upscale Tres at the FlisKits 8th anniversary celebration https://www.rocketryforum.com/showthread.php?p=137275 see posts 34-36.

Slightly opened up the hole in the NC so the escape tower freely drops in and out. Then tethered them together with an 18" Kevlar string.

Knotted each end of the Kevlar. Drilled a small hole in the base of the escape tower and used a piece of toothpick and slow epoxy to fasten Kevlar. Used a stick to drip 1-2g of epoxy directly to the bottom of the NC hole and set the other knotted end in there.

Air pressure should keep the light weight escape tower in place during upward flight, then during recovery it will drop out and hang below the rocket.

Final step - bonding the boosters to the core.

Taped around bonding points on the core and sanded them to roughen and expose fresh fiberglass surface. Then removed tape.

Taped around bond points on the boosters and sanded bond points there too. Removed tape on each booster after applying a bead of 5 minute Locktite epoxy.

Made a fixture from popcicle sticks, tie wraps, paper towel, tape and body tube to slightly squeeze sides of booster so as to bulge it near bond area and optimize fit to core during gluing.

Before painting had precisely cut tiny notches with a triangle file at the bottom of the core and boosters to facilitate alignment during bonding.

Completed rocket!

I am both pleased with the result and glad construction is done. Showed rocket to the family and my daughter said it looks like it should take a mouse into space.

Top section weighs 49.65 oz with altimeter sled. Bottom section is 47.25 oz. Recovery and motors not included. 6 lbs as shown, 8.5 lbs flight ready.

Rocket is 60.5 inches tall with a CG at 34.5" from very top of rocket, or 4.5" behind the recovery separation point.

This week will prep recovery, motors and igniters.

n3tjm said:

What motors do you plan to fly it on for its first flight?

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Planned motors for the Soyuz' first flight:
1x ProX 29mm 3grain G125 Red
16x Estes D11-P

total impulse: 477 Ns
average thrust: 301 N
= I-301

More detail in posts 29 and 34.

WOW!!

Great looking rocket, the detail is amazing!

Very nice, Boris!

-Kevin

Exellent build Boris ,very good looking piece of kit (very inspirational to say the least)

Although I prefer a matte finish on scale rockets ,I also usually go gloss ,for ease of decals/transfers and as you mentioned..CLEANING !! Something about flat white rockets and muddy fields ,where as a nice gloss kit just wipes down with water and a rag.

Take care


Paul T

I look forward to seeing it this Saturday at Amesbury.

D@mn, Boris, now I know I'm a hack, and will never ever be able to build anything as nice as your stuff.

Unbelievable work! Very impressive!

You've put me to shame once again!

G.D.

Now that is stunning, fantastic work! The boosters came out really smooth, did you fill the fiberglass weave with anything prior to primer-n-paint? I used 1.5oz glass on mine and the weave is fairly pronounced, I don't want to oversand them for fear of sanding into the cloth. Maybe I didn't wet out the fabric enough...?

Hopefully someone will get video(s) of your launch, this has definitely been one of my favorite threads to follow and I can't wait to see how it flies.

Thanks for the kind words all.

Spurkey,

Looking closely at my boosters with the naked eye, a slight weave pattern is visible. I filled a few small areas with Spot Bondo where there was actual pitting, but did not take the steps necessary to remove any signs of texture.

Part of what reduces the visibility of the texture is the multiple build ups of paint. For the white base coat, I did two light coats of primer and then over three days 2-4 coats each day of Krylon Gloss White. That covers a lot of tiny surface imperfections.

Spot Bondo is good for small areas but gets messy for more than that. Wiping on more epoxy can fill surface texture, but adds weight.

A technique that has worked well for me on other projects is to brush on coats of latex primer. Two+ days later, sand it until you just start to see the underlying surface. Then spray prime and spray paint.

The latex goes on very thick compared to spray paint and fills a lot of small blemishes. It also weights and costs less than epoxy. I have done this twice on other projects and been very happy with the result. One was my L2 project, a modified Sirius Rocketry Saturn V, details on bpasa.com and TRF.

I will have a Boostervision (video) Gearcam taped to the rocket on the side facing away from spectator view, and also shoot DSLR stills and HD video from the ground. Flight details, pictures and video will be posted.

Nice, very nice Boris! Eagerly awaiting the flight photos and video.

Final prep.

Loaded motors, 16x D11-P and 1x G125 as previously noted.

Packed chutes. Using a Top Flight Recovery 45" chute for lower section and 36" for upper. Both chutes measure out to about 3" larger than rated sizes, so recovery rates should be reasonably slow. Chute space is tight, 2.5" diameter x 21" long. Setup is very similar to: https://www.rocketryforum.com/showpost.php?p=92113&postcount=46

Prepped igniters, Rocketflite ML mostly wired in series pairs of two to reduce current load. Will be fired by cluster box: https://www.rocketryforum.com/showpost.php?p=111556&postcount=18

For ejection charges using 1g BP fired by Rocketflite MF ematches.

Had to tack corners of stainless steel tape down with CA as they were starting to separate. Two days ago filleted booster to core bonds at bottom of rocket.

Beautiful work!
I look forward to the flight pics and video.

Congratulations! That is one awesome build!

I believe you mentioned early on that this started out as a kit, and as such has been proven to be flight stable. But I am curious how stable it is. My gut feeling tells me that this model is on the very edge of stability.

My knowledge of fluid dynamics is armchair at best, but the complex shape of the booster pods leaves me to believe that the fins will be operating in some rather turbulent air, reducing the effectiveness of the smallish fins to begin with. I believe this would make simulation using anything less than CFD tools not terribly accurite.

If anyone has any comments on this I would sure love to hear them. And needless to say, like everyone else here, I am on the edge of my seat for launch videos!