Soyuz build from Cosmodrome Vostok

Ahhhh, I see now. Nice idea. Yes, cutting the lower slot in the boosters is a challenge. I used a long e-xacto blade for this, #26 to be exact.

Spurkey said:

I can put up some pics when I get home if Boris doesn't mind me temporarily hijacking his thread.

Click to expand...

Please do post pictures of how you did this. Also pics of your completed Vostok. Has it flown?

Spurkey said:

Woo! My favorite thread is active again. Your experience with your Soyuz led me to modify my Vostok build in a similar manner....

Will you be surface-mounting your posts on the central core or will you cut a similar hole to go down to the motor mount?

Click to expand...

Thanks.

My current plan is to use slightly thickened West 206 epoxy, with small holes drilled where possible and surface roughened for re-bonding.

Leaning towards surface mounting to the core as the position of the rectangular pegs is too low to be completely through the wall.

Original bonding, which failed, was 5 minute epoxy with no holes and much smaller purely surface mounted posts at the bottom.

In my usual timely manner *cough* here're some pics. I put two dowels in for support but I think that's unnecessary, one would've been fine. You can also see evidence on the booster of my genetic predisposition to measuring things incorrectly. As my grandfather, rest his soul, was fond of saying "I cut this twice and it's still too short". The posts are at a right angle to the core tube thus requiring them to be at a right angle to the booster surface. This was tricky to drill even with a drill press because the tapered, rounded shape of the boosters made them very difficult to clamp securely. I used 'regular' HSS bits which wandered more than I liked, a brad point bit would've been a better choice.

Also visible are little divots in the booster fibreglass surface to try and give the epoxy something more to bite into, I don't know how effective they'll be since the Dremel bit I used still left a fairly smooth surface inside the divot.

delta22 said:

Also pics of your completed Vostok. Has it flown?

Click to expand...

Sadly it is still, still not completed. It's going to have its 3 (three!!) year construction-start anniversary in just over 2 months, I think it & I are gonna go out for a drink to commiserate if I'm still building by then. Part of the lengthy build is due to me going a bit overboard with correcting the scale of the Vostok section. I also wasted a ton of time trying to calculate if 3 chutes on the lower section were feasible from both a descent rate and a packing perspective. I'm pretty sure 3 30" Spherachutes would do it however I've realized I don't have the intestinal fortitude to try, not for the first flight.

You are doing some fine scale work there.

The chute recovery space is tight and the investment in labor is huge, I would suggest the chute setup the kit recommends and that I used. One chute for each recovery section.

Also recommend adding a Nomex sheet attached to the upper recovery harness and wrapping both chutes with it. By making sure the recovery "burrito" is packed in such a was to just fill the recovery storage tube, without being tight in it, have had 9 successful deployments (8x Thunderbird + 1x Soyuz).

Also suggest drilling the surface bonding "divots" to make them small holes. That is what I plan to do as part of my repairs. Gives the epoxy more to grab onto.

Catching up on posts:

> Numbered each booster and sanded to get best fit to core section.

> Formed 0.75" x 1.25" through-the-wall pine posts to anchor base of boosters to core.

> Epoxied these with five build-ups of West 206 into each booster.

Drilled a series of small holes along all contact areas between core and boosters, to give epoxy more to bond to.

Only area not drilled was the area of the core that has no inner wall = chute compartment.

Touched up the white paint on 3 of the boosters.

Also re-painted the orange on all 4 boosters and the core.

This should have been a quick task, but took much longer because of repeated orange peeling of the paint.

I sanded surfaces before painting, followed all instructions on the can, and did not paint while it was raining, but still had repeated problems with Krylon.

Carefully bonded each booster to the core using West 206 epoxy thickened with colloidal silica.

Bonded one booster each night for four nights, checking alignment repeatedly as the epoxy dried.

The white ring fixture shown was used to slightly pinch the center of the boosters so that their bonded area would better align with the core.

The core to booster bond is much stronger and stiffer than it was with the original build, which is the desired result.

Wow, I don't know that I've ever seen tape used to hold tape in place before.

Spectacular build! A flight will look amazing with all the smoke from the engines when they're ignited!

Will this be flying on Saturday?

cosmodrome said:

Wow, I don't know that I've ever seen tape used to hold tape in place before.

Click to expand...

Another example of (model) rocketry pushing the envelope in (masking tape) materials bonding technology.

Mike, how are you doing? Hope all is well.

Haven't seen you at a CMASS launch in quite some time. Hope to see you at the CMASS 4/27/13 launch.

delta22 said:

Another example of (model) rocketry pushing the envelope in (masking tape) materials bonding technology.

Mike, how are you doing? Hope all is well.

Haven't seen you at a CMASS launch in quite some time. Hope to see you at the CMASS 4/27/13 launch.

Click to expand...

I'm good. Planning on being at the launch

skybuster said:

Spectacular build! A flight will look amazing with all the smoke from the engines when they're ignited!

Click to expand...

Thanks, I like that you are using recycled electrons, shows a real commitment to protecting the environment

Pictures and video of the first, and only previous flight, are in posts 125 through 137 of this thread for a preview of what is to come...

berlinetta said:

Will this be flying on Saturday?

Click to expand...

Yessir, Soyuz repairs are completed and final flight prep is in process.

(This tribute to) the Russian space program will launch at the CMASS 4/27/13 launch in Amesbury, MA.

Long range weather predictions are looking pretty good.

delta22 said:

Thanks, I like that you are using recycled electrons, shows a real commitment to protecting the environment

Pictures and video of the first, and only previous flight, are in posts 125 through 137 of this thread for a preview of what is to come...

Click to expand...

Haha, thanks! Awesome photos, must have been a bear wiring up 17 engines

skybuster said:

Haha, thanks! Awesome photos, must have been a bear wiring up 17 engines

Click to expand...

Ya, Boris had a bear of a time wiring up 17 motors. His biggest problem was stopping at 17. Normally he doesn't finish til 30 or 40. :lol:

skybuster said:

Haha, thanks! Awesome photos, must have been a bear wiring up 17 engines

Click to expand...

If you would like to see how I power and wire cluster ignitions, please check out the Cluster Box and Rocketflite links on the website in my signature.

pic 1: After several more build-ups of epoxy, the base of the boosters are very firmly anchored to the core.

pic 2: Standing the rocket up fully assembled. Taking the picture from a low vantage point, the rocket looks a lot taller that its 60.5 inches.

pic 3: Installed the Featherweight Raven altimeter / flight computer in order to capture detailed flight data.

Recovery deployment is a single event at apogee, with the primary ejection charge triggered by the Raven. Motor backup ejection charge 1 to 2 seconds after predicted apogee.

After reviewing flight performance from the Soyuz' first flight and comparing to the preferred cluster for my English Electric Thunderbird, selected the cluster of motors for the Soyuz flight Saturday:

1x ProX F30 (24mm 3grain 73Ns)
8x Estes E9
8x Estes D12

433Ns total impulse = I impulse
198N average thrust, average burn duration 2.2 sec, with the E9 burns ending at 2.8 sec

This will provide a moderately slow, long-burning flight that should be fun to watch.
Sim predicts 8.4G acceleration off the pad, max velocity of 130mph, and peak altitude of 770ft.

This motor selection is an expanded set of the same motors used to good effect over many flights on the Thunderbird, providing the same flight profile for the heavier Soyuz.
Soyuz flight weight will be about 9.6lbs, including the 1lb nose weight added for this flight to improve stability and compensate for slight added motor weight.

First flight had a faster burning cluster and hit about 180mph max velocity. Saturday's flight will be about 50mph slower peak speed. This plus the added nose weight will hopefully prevent the rocket from coning as it did at the end of the first flight.

The Aero Pack retainer and motor adapters made it easy to adapt the 38mm motor mount down to 29mm then to 24mm very cleanly.

cosmodrome said:

Ya, Boris had a bear of a time wiring up 17 motors. His biggest problem was stopping at 17. Normally he doesn't finish til 30 or 40. :lol:

Click to expand...

WOW!!! That's impressive! I'm guessing that many clustered is covered under HPR certification and the HPR code?

delta22 said:

After reviewing flight performance from the Soyuz' first flight and comparing to the preferred cluster for my English Electric Thunderbird, selected the cluster of motors for the Soyuz flight Saturday:

1x ProX F30 (24mm 3grain 73Ns)
8x Estes E9
8x Estes D12

433Ns total impulse = I impulse
198N average thrust, average burn duration 2.2 sec, with the E9 burns ending at 2.8 sec

This will provide a moderately slow, long-burning flight that should be fun to watch.
Sim predicts 8.4G acceleration off the pad, max velocity of 130mph, and peak altitude of 770ft.

This motor selection is an expanded set of the same motors used to good effect over many flights on the Thunderbird, providing the same flight profile for the heavier Soyuz.
Soyuz flight weight will be about 9.6lbs, including the 1lb nose weight added for this flight to improve stability and compensate for slight added motor weight.

First flight had a faster burning cluster and hit about 180mph max velocity. Saturday's flight will be about 50mph slower peak speed. This plus the added nose weight will hopefully prevent the rocket from coning as it did at the end of the first flight.

The Aero Pack retainer and motor adapters made it easy to adapt the 38mm motor mount down to 29mm then to 24mm very cleanly.

Click to expand...

Looks amazing! Can't wait to see how she flies!

(BTW: thanks for the clustering link

At about 1pm on a beautiful sunny day at the CMASS Amesbury 4/27/13 launch, the Soyuz lifted off on a column of fire and smoke for a very nice flight.

All 17 engines fired and both Top Flight Recovery 45 inch chutes deployed cleanly.

This second flight was nice and straight, without the coning seen on the first flight.

The boosters remained firmly attached to the core as intended, and all major sections of the rocket are in great shape.

Featherweight Raven altimeter reported the following maximum values:
acceleration: 7.0 Gs
velocity: 109 mph
altitude: 709 ft

Before and after pictures plus the Raven altimeter data.

The excellent Rocketflite CF igniters are mostly wired in series strings of 2 and then those are joined in parallel, reducing total current load.

Used this method of wiring Rocketflite igniters plus my cluster box with high output LiPo battery to fire this flight, and other 3 cluster flights today, firing all 44 motors loaded in the 4 flights. Please website in my signature for more details.

Got video from several cameras, will edit and post those tomorrow.

Congratulations on another spectacular mega-cluster flight. It was very impressive.

Bob

Interesting how off angle the flame is on the F30. I heard that can happen on moon burners, but that bad?

I was RSO when Boris brought this to the table. I could not believe how heavy this rocket was for it's size. It is impressive at liftoff. I can't wait to see it fly again. Also, Boris flew his UFO and it put on another impressive flight. Congratulations Boris and Thank you for all the excitement.

Got the video edited:

[video=youtube_share;6ZolFWCGCPQ]https://youtu.be/6ZolFWCGCPQ[/video]

Thanks for the kind words all.

I've fired a number of Pro-X 24mm 3grain F30 engines, as they have a regressive, 2.4 second burn that looks good in the middle of a cluster of BP engines. This was probably the most crooked flame I have seen from one, usually their white flames look pretty straight.

The Soyuz is 5ft tall and flew at just under 10lbs. The rocket splits in the middle for recovery, and each half weights 3lbs dry. The 17 engines added 2lbs, balanced by more than a pound of lead in the nose, and recovered on two 4ft Top Flight Recovery chutes.

Clustered rockets tend to end up heavy because of a high motor weight at the tail of the rocket, often requiring nose weight for stability, which then requires more motors.....:wink: