Multi Stage Saturn V

[Daddyisabar]

28 degrees is just a bit nippy for a hardened mountain man. It's a dry cold. Only five more months until spring in the high country!

 

[lakeroadster]

Meh. You wear a coat, wear gloves when you can, you're out of the wind – hey, that's where the tools are, so ya do what ya gotta do.

28 degrees is just a bit nippy for a hardened mountain man. It's a dry cold. Only five more months until spring in the high country!

Gloves are the issue. Wearing them when using a drill press is out of the question. And all the tools in the barn are also 28 F. I'm not complaining.. just explaining.

 

[lakeroadster]

Stage One Motor Mount Build - Day 02

Installed the thrust rings and then sanded the o.d. of the upper ring for a slip fit into the BT-300.

I then fired up the cad station and made a template for the staging fuse header. Then sliced and diced some BT-50 for the header.

The C-50 coupler is just being used as a fixture, as well as the thrust rings that are inserted in the motor tubes.

I plan to glue the header joints, inside and out, and then apply a liberal coating of wood glue to the entire inside of the tubes to help protect it from the staging blasts.

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[lakeroadster]

Stage One Motor Mount Build - Day 03

This build reminds me of something Axle Rose once told us

.... take it slow and it'll work itself out fine
All we need is just a little patience
Said, sugar, make it slow and we'll come together fine
All we need is just a little patience
Patience, mm yeah...



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[Grog6]

OP, if you're working in the cold, and gloves are a problem, You'll want to make a hot box to cure epoxy in; It has to be big enough for what you're working on. Epoxy doesn't cure well in temps we find uncomfortable. I tried using lamps for heat, but settled on a heat tape from MSC, mounted to an old heatsink from a pc, the fan keeps the temp constant.
I wear two layers of nitrile gloves; the air layer between them helps a lot.
I also put a piece of heat tape on the bottom of my toolbox' drawers; the tools are toasty and dry, and won't make your hands hurt.

 

[jqavins]

Stage One Motor Mount Day 02

Stage One Motor Mount Day

Hats off, gentlemen: a genius.

 

[lakeroadster]

Musings..

As I begin my 3rd day of gluing a motor mount here in our warm mountain cabin, while it's 5 degrees Fahrenheit outside, I look at the mount and noticed it has kind of a Colonial Viper vibe going, and then thought: "What if I borrowed the BT-50 nose cone from my X-Wing and launched this 1st stage motor mount as a stand alone rocket"?
Ok.. focus on the task at hand... I wonder, is it possible to hallucinate from sniffing wood glue? and speaking of "mount", do they still make this glue from dead horses?

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[lakeroadster]

Stage One Motor Mount Build - Day 05

1st Stage is done, except for fins and fairings.

I think I'm going to use a series of screws to attach the two sections of the BT-300 body tubes together. This will allow me to access the upper section of the motor mount and the staging tube... just in case there is something that needs attention in the future.

 

[lakeroadster]

Stage Two Motor Mount Build - Day 01

This one is much less complicated, the staging header is just a 18mm body tube.

I deviated from the original design by adding a 24mm motor block to the outside of the center 18mm tube. This will allow me to glue the 5 tubes together, thus making them much stronger and less prone to damage.

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[lakeroadster]

Stage Two Motor Mount Build - Day 02

Finished the motor mount.

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And started making some 0.09" thick basswood plywood for the 1st and 2nd stage spool rings...

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[lakeroadster]

Spool Centering Rings

Used the fly cutter to extract the spool centering ring from the 0.09" basswood plywood. I had to stack clamp them, they started to curl after I cut them. An indicator that they are still not dry from the gluing process.

As an FYI:

• I like using 1/32 basswood because it allows for (3) plies and thus a good cross grain stack up is possible. I used this same configuration for the fins on my Ahpla and it made for a very strong 0.09" thick material.
• But since each ply is only 0.030" thick the fly cutter does tend to splinter the edges a bit. If you find the splintering to be an issue, cut the o.d. a bit oversized, and then sand it down to size.

 

[lakeroadster]

1st Stage Recovery / Staging Spool

This spool serves 3 functions:

1) The second stage fuses are routed up through the center,​

2) The gases from the 1st stage booster motors are routed vertically up through the center and then horizontally out through the tube / fuselage,​

3) The parachute is packed in the outside of the spool, the 1st stage ejection charges push the spool out of the 1st stage fuselage.​

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Initially I planned to use a BT-3 cardboard tube for the fuse conduit. Upon further review... there's a chance the quick burn staging fuses will torch the tube. I checked with Engineering, and we decided to initiate an ECO (Engineering Change Order) to use a piece of 3/8" aluminum tubing instead of the BT-3.

I flared the upper end of the aluminum tube to make insertion of the fuses easier, and then used a short piece of BT-3 tubing, cut longitudinally, as a collar. The collar slips over the the aluminum tubing to allow using wood glue to attach the BT-3 to the internal BT-104 basswood ply centering ring.

My homemade centering rings are still warping like a Pringle when left unrestrained ... so as King Longshanks always liked to say.... "Rack Him"

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[Daddyisabar]

Just be careful not to awaken the little devil on your shoulder who will weight shame your mods. The dreaded bean counters don't like weight on the bottom when it comes to generating that lovely speed off the pad needed for nice staging and the mindsimed spin stabilization.

Crush the dreaded Longshanks! All it takes is putting on a kilt, painting the rest of the body with Woad and getting a motivational speech from Mel after goodly amount of single malt!

 

[lakeroadster]

Just be careful not to awaken the little devil on your shoulder who will weight shame your mods. The dreaded bean counters don't like weight on the bottom when it comes to generating that lovely speed off the pad needed for nice staging and the mindsimed spin stabilization.

Crush the dreaded Longshanks! All it takes is putting on a kilt, painting the rest of the body with Woad and getting a motivational speech from Mel after goodly amount of single malt!
View attachment 560181

What's with your face William? Why so blue?

Woad... Isatis tinctoria... Asp of Jerusalem... all things I learned on The Rocketry Forum today.

 

[Daddyisabar]

Gotta love Mel's movies. Historical accuracy not so good but boy can he paint his actors blue! Hopefully the launch will not be an Apocalypto.

 

[GlenP]

You could do some torch testing with the fuse and your staging tube, if not too expensive to burn your money. The quick burn fuse may get pretty hot, but it also burns out quickly. A thin coat of glue or epoxy may be sufficient to help the cardboard tube survive a few launches. Other options might be high-temp BBQ paint, or Aluminum dryer duct tape as a liner, cut a soda pop can and make your own thin walled tubing. Or, a sacrificial replaceable baking parchment paper liner. Not sure if any of those options will perform any better at any lighter weight or not, just other ideas to throw out there for consideration by the engineering group.

Great idea to make the end a flare/funnel to help thread the wick/fuse through!

 

[Daddyisabar]

TRF: Enter with a skull full of mindsiming mush, leave thinking like a true Rocket Scientist!

When fearing heat and needing strength I coat the inside of the paper tube with thin CA. It's SMOKIN'! COUGH, COUGH, CHOKE. CHOKE...SPIT! I'm crying in pain! Make the sacrifice for ultimate model rocket performance!

 

[lakeroadster]

You could do some torch testing with the fuse and your staging tube, if not too expensive to burn your money. The quick burn fuse may get pretty hot, but it also burns out quickly. A thin coat of glue or epoxy may be sufficient to help the cardboard tube survive a few launches. Other options might be high-temp BBQ paint, or Aluminum dryer duct tape as a liner, cut a soda pop can and make your own thin walled tubing. Not sure if any of those options will perform any better at any lighter weight or not, just other ideas to throw out there for consideration by the engineering group.

Great idea to make the end a flare/funnel to help thread the wick/fuse through!

I went with the wood glue coating to coat and seal exposed cardboard..

The spool tube (BT-104) slides over the header tube (BT-50H). I coated the BT-50H internally with wood glue.

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I have a bit of experience with the wood glue method:

The internals of my F-79 are coated with wood glue. The F-79 has dual d12's that eject forward and the gases impinge on the screwed in place nose cone shoulder, adjoining side pods have port holes shared with the main body, the pressure wave from the ejection pushes the chutes out the back of the rocket. After launch I removed the nose cone and the amount of motor debris was eye opening, but the charring to the actual rocket itself wasn't as bad as I had anticipated.​

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On my Mercury LES it has (3) D12's that eject, impinge on the bottom of a Red Bull can and the pressure wave travels down about 13" of BT-50H, which pushes the chutes out the bottom of the capsule. It was surprisingly clean internally after the flight. I had staggered delays... so it's kind of self cleaning. ​

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[GlenP]

I was just suggesting that those similar techniques you typically use for the staging and ejection charge ducts might work just as well for your fuse conduit, as an alternative to that small dia Aluminum tube. But, probably a toss up, if there is any chance of weight savings at all.

 

[lakeroadster]

Alignment Fixture for the Fuse Conduit

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[lakeroadster]

Started gluing on the 1st stage recovery spool rings.

I'm using the actual staging tube (BT-50H) as a rounding fixture while gluing the rings onto the spool tube (BT-104). The spool has to be a sliding fit, so I'm trying to be careful to keep the BT-104 as round as possible. Once the glue has started to solidify, I'll remove the toothpicks to ensure they aren't making the tube obround.

BT-50H Outside Diameter = 0.990 inches​

BT-104 Inside Diameter = 1.000 inches​

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Snug as a bug in a rug... ​

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And here are the finished spools slipped onto their respective motor mounts.

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[aerostadt]

It will be interesting to see how this turns out using an older ignition system.

 

[lakeroadster]

It will be interesting to see how this turns out using an older ignition system.

It's been done before, ref. @heada post #45

I used only a single booster motor so that all staging is based on that motor. The others were standard delay motors. I also wrapped the paper fuse (not quick match!!, that's regulated) with aluminum tape so that if the booster motor didn't fire for any reason, the delay motors didn't light the paper fuse

1st stage: 4x C6-5 & 1x C6-0. C6-5 had parachutes in their tubes and the C6-0 had the paper fuse taped into the ejection well.
2nd stage: 4x C6-5 & 1x C6-0. Same configuration as 1st stage
3rd stage: 1x C6-7 gap staged from central motor of second stage.

I used 1/16" plexiglass fins on 2nd and 3rd stage. From a distance, you could hardly see them. Very interested if this finless version will work. I have 3 of the 1/100 Estes kits and would be willing to build 1 of those as a 3 stage with finless 2nd and 3rd stages.

 

[Daddyisabar]

That's gonna be a mega complex whoosh popper!

 

[lakeroadster]

Pretty decent temp's here today, pushing 50 F, so I chucked some redwood into the lathe and made the Interstage Transition and the Command / Service Module / LEM Adapter.

I still need to drill the hole in the transition for the internal launch lug.

Pretty pleased with the results, just needs some CWF.

Notes to self:

1. Don't stir the cryo tanks...
2. Using a higher RPM makes redwood much easier to turn
3. I made these parts using the same piece of redwood. Screwed a 4 x 4 piece of redwood to the faceplate. Turned the Interstage Transition 1st, parted it off, then made the Command / Service Module / LEM Adapter.

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[bad_idea]

Always remember to order your cryo tanks shaken, not stirred.

 

[lakeroadster]

Always remember to order your cryo tanks shaken, not stirred.

0-0-7 ​

NaN-NaN-NaN-NaN, NaN-NaN-NaN-NaN​

Hey hey hey, goodbye​

Drilled the hole for the internal launch lug. I anticipated that it would be problematic... drilling so close to the edge of the shoulder... but... it was a piece of cake. Forstener bits are da bomb!

I used a spent 18mm motor casing as a dowel to hold the transition into the vise.

 

[GlenP]

I don't remember if you already have drawn a detail like this in your plans, but in a similar fashion that you have made a little internal funnel to route the fuse into the conduit, you could add a little internal transition/funnel at the bottom end of that internal lug hole to help you thread the fully assembled rocket onto the launch rod.

 

[lakeroadster]

I don't remember if you already have drawn a detail like this in your plans, but in a similar fashion that you have made a little internal funnel to route the fuse into the conduit, you could add a little internal transition/funnel at the bottom end of that internal lug hole to help you thread the fully assembled rocket onto the launch rod.

Timely comment.

The 2nd stage internal BT-3 launch lug actually inserts into this transition, to avoid any hick-ups inserting the 5/16" launch rod at the launch site.

Just like an alignment dowel.

 

[lakeroadster]

Cut the 2nd & 3rd Stage Body Tubes & then started gluing in the 2nd stage internals.

Mocked up all the stages and thought to myself.... "There's that profile we've all grown to love"

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Here's the 3rd stage as it will be flown. The Interstage Transition provides much needed base drag for stability.

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3rd Stage as planned for recovery...... and 4th stage as planned for recovery

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And gluing in the 2nd stage internals.

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