Multi Stage Saturn V

[lakeroadster]

I reworked the Open Rocket simulation and added another stage for the Launch Escape System.

Even though I set the LES Ignition to be based on the 1st stage D12-0's, Open Rocket still thinks the LES is the last stage, which meant the plot was not correct. So I pulled the plot into Microsoft Paint and added the LES profile in red.

 

[Daddyisabar]

Soylent Glue is @Daddyisabar

It would end the glue debate forever! Pure white tacky, dries clear with just a few tiny bubbles. Strong, heat resistant, flexible and will bond any roughed up surface!

Use any leftovers for fight club soap. AP scented with pumice.

 

[lakeroadster]

It would end the glue debate forever! Pure white tacky, dries clear with just a few tiny bubbles. Strong, heat resistant, flexible and will bond any roughed up surface!

Use any leftovers for fight club soap. AP scented with pumice.

You're on the top of the **** list now. You're talking about "Fight Club"

 

[Daddyisabar]

You're on the top of the **** list now. You're talking about "Fight Club"

Oopsie! You can't render out the naughty side.

 

[lakeroadster]

Oopsie! You can't render out the naughty side.

Not only can I render it out... I can grind it up into 1" cubes, cook it, press it, and feed it to the chickens...

 

[Daddyisabar]

If this has already been covered I apologize for not having picked it up.

Approximate Motor burn times (thrust duration) of C11 is .8 seconds. D12 is 1.6 seconds. So first stage will be approx .8 seconds on just one D on the low side of it's thrust curve. Plus the time it takes for the fuse to ignite the second stage and the motors to come up to thrust. (.1 to .2 seconds?) OK???

Staging experts confident???

Pop a 30 oz. Saturn V Rocket off the pad (4:1ish thrust ratio at start?) and keep going straight up through staging after D12 burns out .8 seconds later and second stage thrust kicks in .2 seconds later? Just saying.

Given the slight differences in ignition and burn times of BP motors is the "sin" sufficiently spread out?? Slightly different thrust patterns to result in wobble? No fear.

Fear is the mind killer Daddy! Too many questions. No need for more power. The rocket is only 30.9 oz. at liftoff. It will be fine. The computer says so. Quit looking at the charts in the back of the Estes catalog and mindsiming. Chill out, trust the simulation and take a stress pill!

 

[Daddyisabar]

Not only can I render it out... I can grind it up into 1" cubes, cook it, press it, and feed it to the chickens...

But I might have Mad Cow disease. Very susceptible after way too much silly mindsiming and building their kits. Save the chickens!

 

[lakeroadster]

If this has already been covered I apologize for not having picked it up.

Approximate Motor burn times (thrust duration) of C11 is .8 seconds. D12 is 1.6 seconds. So first stage will be approx .8 seconds on just one D on the low side of it's thrust curve. Plus the time it takes for the fuse to ignite the second stage and the motors to come up to thrust. (.1 to .2 seconds?) OK???

Staging experts confident???

Pop a 30 oz. Saturn V Rocket off the pad (4:1ish thrust ratio at start?) and keep going straight up through staging after D12 burns out .8 seconds later and second stage thrust kicks in .2 seconds later? Just saying.

Given the slight differences in ignition and burn times of BP motors is the "sin" sufficiently spread out?? Slightly different thrust patterns to result in wobble? No fear.

Fear is the mind killer Daddy! Too many questions. No need for more power. The rocket is only 30.9 oz. at liftoff. It will be fine. The computer says so. Quit looking at the charts in the back of the Estes catalog and mindsiming. Chill out, trust the simulation and take a stress pill!

Yeah, it was discussed previously, but hashing and rehashing is OK in Amsterdam, so what the heck we can do that here too.

Revised: The 1st Stage D12-0's light the fuse... The 1st stage C11-3's deploy the 1st stage chutes around 2 seconds later

 

[Daddyisabar]

Yeah, it was discussed previously, but hashing and rehashing is OK in Amsterdam, so what the heck we can do that here too.

I think the staging will be just fine. Once the C11-0 expires... the fuse lights and there will be a delay for the fuse (0.067 to 0.267 sec) and then there's the slight delay for the fuse flames to ignite the BP motors. But with (5) B 2nd stage motors firing all at nearly the same time, that will separate the stages. If the D12's are still burning in the 1st stage at stage separation, I don't see that as an issue. Theoretically, the 1st stage is stable all by it's self. Sure it's less aerodynamic than a pig... but it sim's as stable.

View attachment 565300

Ok. The fuse is off a C11 0. Better, just saw C11 3 on the sim.

 

[lakeroadster]

Ok. The fuse is off a C11 0. Better, just saw C11 3 on the sim.

Nope... I screwed that up. You are correct.

The C11-3's stop thrusting while the D12-0's are still burning. The D12-0 then stops thrusting and ignites the fuse. Around 2 seconds later the C11-3 ejection charge deploys the 1st Stage spool and deploys the chute on the 1st stage

 

[Daddyisabar]

Good, like Santa, checking it once, checking it twice. Gonna find out who's naughty and nice.

I like lighting the fuse early! Get second stage moving asap. C11 0 rock off the pad but lack staying boost power. Put a little BP on top for assurance. A D12 still burning on the end of the curve isn't much thrust.

 

[lakeroadster]

Bench Test: Visco Quick Burn Fuse Used For Motor Staging (Post 1 of 4)

I'm happy to report that it looks like the fuse is going to work for igniting the 2nd stage B6-4 motor cluster.

That being said... now that I've seen up close and personal the sparks / flame front that is generated by the fuse, I will not being using it to ignite the LES motor. Taping the fuse to the outside of the rocket, up to the LES, is just not prudent, IMO.

​

 

[lakeroadster]

Bench Test: Visco Quick Burn Fuse Used For Motor Staging (Post 2 of 4)

 

[lakeroadster]

Bench Test: Visco Quick Burn Fuse Used For Motor Staging (Post 3 of 4)

 

[lakeroadster]

Bench Test: Visco Quick Burn Fuse Used For Motor Staging (Post 4 of 4)

​

 

[BABAR]

Bench Test: Visco Quick Burn Fuse Used For Motor Staging (Post 1 of 4)

I'm happy to report that it looks like the fuse is going to work for igniting the 2nd stage B6-4 motor cluster.

That being said... now that I've seen up close and personal the sparks / flame front that is generated by the fuse, I will not being using it to ignite the LES motor. Taping the fuse to the outside of the rocket, up to the LES, is just not prudent, IMO.

View attachment 565510

View attachment 565511
​

if 39 inches of fuse burns in 0.802 seconds, then isn‘t the burn rate 48.628 inches per second?

or 4.05 feet per second?

 

[BABAR]

Outside the box thinking (lot of that already in this puppy).

If I have the design right, the fourth stage is rear eject, so comes down nose first.

Build the launch tower out of wood, use long toothpicks or wooden skewers so the legs extend about an inch longer than the attachment points.

Drill holes in the nose when the attachment points are going to go. Holes need to be a leeeeettle big, so it slides in and out easily.

You will need a thin strong cord (Kevlar thread is nice), that rolls up inside the tower and has an attachment point to the tip of the rocket. You could also put it somewhere else, and have a dangling cord at launch, if the cosmesis doesn't bother you too much. The cord should roll up completely inside the tower for display purposes.

On display, gravity holds the launch tower in place. At launch, the acceleration of the rocket holds it in place (drag separation during the multiple staging events MAY be a problem, I dunno.)

Having it removable also will make transporting and storing the rocket a lot easier, one less fiddly bit to brake off.

At deployment, the Fourth Stage is dangling by the parachute. You have a bit of weight in the tip of the launch tower. The tower slips out of the nose, and dangles from the cord. It's still gonna hit the ground, but it is only hitting the ground with it's own weight, which is pretty minimal, rather than being the tip of a relatively heavy entire fourth stage. So it will have the same impact velocity, but far less intertia.

Alternatively there is this, which I think is how the tower was ACTUALLY jettisoned, where you kind of have a built in saucer recovery. I would still harness it to the fourth stage, as finding this thing as a piece by itself (a FIFTH thing to track) is gonna be a PITB. The toothpick or skewers still could be useful here, may only need two or three instead of four to match the legs, to keep it aligned for flight and display purposes. Would make hiding the attachment cord a lot easier.

 

[Long_Gone]

Getting another bag of popcorn, episode 3 is on right now.......This is going to be good!

 

[Daddyisabar]

Getting another bag of popcorn, episode 3 is on right now.......This is going to be good!

Who needs to go to the expensive theater to see Cocaine Bear when you have TRF !

 

[lakeroadster]

Outside the box thinking (lot of that already in this puppy).

If I have the design right, the fourth stage is rear eject, so comes down nose first.

Build the launch tower out of wood, use long toothpicks or wooden skewers so the legs extend about an inch longer than the attachment points.

Drill holes in the nose when the attachment points are going to go. Holes need to be a leeeeettle big, so it slides in and out easily.

You will need a thin strong cord (Kevlar thread is nice), that rolls up inside the tower and has an attachment point to the tip of the rocket. You could also put it somewhere else, and have a dangling cord at launch, if the cosmesis doesn't bother you too much. The cord should roll up completely inside the tower for display purposes.

On display, gravity holds the launch tower in place. At launch, the acceleration of the rocket holds it in place (drag separation during the multiple staging events MAY be a problem, I dunno.)

Having it removable also will make transporting and storing the rocket a lot easier, one less fiddly bit to brake off.

At deployment, the Fourth Stage is dangling by the parachute. You have a bit of weight in the tip of the launch tower. The tower slips out of the nose, and dangles from the cord. It's still gonna hit the ground, but it is only hitting the ground with it's own weight, which is pretty minimal, rather than being the tip of a relatively heavy entire fourth stage. So it will have the same impact velocity, but far less intertia.

Alternatively there is this, which I think is how the tower was ACTUALLY jettisoned, where you kind of have a built in saucer recovery. I would still harness it to the fourth stage, as finding this thing as a piece by itself (a FIFTH thing to track) is gonna be a PITB. The toothpick or skewers still could be useful here, may only need two or three instead of four to match the legs, to keep it aligned for flight and display purposes. Would make hiding the attachment cord a lot easier.

View attachment 565579

I'm thinking that running the shock chord outside the Command / Service / Lunar Modules - 4th Stage and attaching it near the CG might be the smart move, maybe even a bridle attachment configuration. ​

​

As to attaching the tower... a 1/4" Internal Alignment Dowel will be used... as shown in post #336.​

​

Same construction, but will no longer have the motor or thrust deflector​

​

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if 39 inches of fuse burns in 0.802 seconds, then isn‘t the burn rate 46.99 inches per second?

or 4.05 feet per second?

You are correct. Thanks. ​

feet per second..... vs...... seconds per foot.​

​

I revised post #402​

 

[lakeroadster]

Another wood lathe project... of the micro scale variety.

 

[lakeroadster]

Launch Escape System - Motor and Alignment Dowel Lathe Turning

Turned from a 3/4" Pine dowel

 

[BABAR]

I'm thinking that running the shock chord outside the Command / Service / Lunar Modules - 4th Stage and attaching it near the CG might be the smart move, maybe even a bridle attachment configuration. ​

​

As to attaching the tower... a 1/4" Internal Alignment Dowel will be used... as shown in post #336.​

​

Same construction, but will no longer have the motor or thrust deflector​

​

View attachment 565613​

You are correct. Thanks. ​

feet per second..... vs...... seconds per foot.​

​

I revised post #402​

Okay, so I believe I a correct in that the plan is for this to release from the fourth stage at apogee, being pulled out by its own mass when the stage inverts and dangle nose down under chute.

if the only thing holding it in is gravity and acceleration on boast, I am wondering (and high power guys like @Steve Shannon or @JimJarvis50 might know.) whether transient decelerations during staging may cause drag separation of the tower prematurely. If this is NOT a possibility, ignore the following.

to keep the tower in place until the fourth stage ejection charge fires, drill a very small (1/8” would work) from the base of the attachment dowel/post, THROUGH the center of the nose to the forward end of the motor tube.

put a midline longitudinal hole in the center of your dowel/post heinie, and GLUE a needle in there so it sticks straight out maybe 1/4” to 1/2”. This is your micro “screw eye”. Emphasize it is NOT the shock cord attachment, it is not that strong, but it SHOULD be strong enough to prevent drag separation as the attachment point for a cotton thread. It should fit in the 1/8” hole easily.

during prep, run a piece of cotton thread through the eye of the needle, run both end down the 1/8” hole to the motor chamber, and run it out through the the motor tube.

when you are ready to put motor in stage 4, insert the tower in the fourth stage, pull the strings taut, and load the motor (the strings should fit between the motor and the tube.) Likely simple the friction alone will be sufficient to hold it in place, but as a belt and suspenders guy, you could do a couple wraps around the motor and tie a knot. Again, I’d think of thread the same way the high power guys think of those break away bolt thingies that keep the nose cone on until the ejection charge fires. Strong enough to maintain integrity during the boost part of the flight but NOT strong enough to function as a recovery system.

i leave up to you the true shock cord attachment for the tower itself.

at ejection, I am pretty confident that the ejection charge will burn the string and release the tower, which assuming a loose fit (graphite would help but is horrendously messy) the tower will slide out under its own weight (or drag separate, which is FINE at this phase of flight.)

I do NOT think the 1/8” hole will significantly decompress the motor tube, so again assuming a loose fit for your rear deployment system, I don’t think this will compromise it.

not sure if this is not the most complex non-electronic rocket ever (especially since @JAL3 never completed the Rube Goldberg Lander, mores the pity!), but definitely one that would benefit from a preflight and launch checklist. I have encountered fecal turbine interaction on much simpler rockets where a checklist would have saved the day.

 

[lakeroadster]

Okay, so I believe I a correct in that the plan is for this to release from the fourth stage at apogee, being pulled out by its own mass when the stage inverts and dangle nose down under chute.

if the only thing holding it in is gravity and acceleration on boast, I am wondering (and high power guys like @Steve Shannon or @JimJarvis50 might know.) whether transient decelerations during staging may cause drag separation of the tower prematurely. If this is NOT a possibility, ignore the following.

to keep the tower in place until the fourth stage ejection charge fires, drill a very small (1/8” would work) from the base of the attachment dowel/post, THROUGH the center of the nose to the forward end of the motor tube.

put a midline longitudinal hole in the center of your dowel/post heinie, and GLUE a needle in there so it sticks straight out maybe 1/4” to 1/2”. This is your micro “screw eye”. Emphasize it is NOT the shock cord attachment, it is not that strong, but it SHOULD be strong enough to prevent drag separation as the attachment point for a cotton thread. It should fit in the 1/8” hole easily.

during prep, run a piece of cotton thread through the eye of the needle, run both end down the 1/8” hole to the motor chamber, and run it out through the the motor tube.

when you are ready to put motor in stage 4, insert the tower in the fourth stage, pull the strings taut, and load the motor (the strings should fit between the motor and the tube.) Likely simple the friction alone will be sufficient to hold it in place, but as a belt and suspenders guy, you could do a couple wraps around the motor and tie a knot. Again, I’d think of thread the same way the high power guys think of those break away bolt thingies that keep the nose cone on until the ejection charge fires. Strong enough to maintain integrity during the boost part of the flight but NOT strong enough to function as a recovery system.

i leave up to you the true shock cord attachment for the tower itself.

at ejection, I am pretty confident that the ejection charge will burn the string and release the tower, which assuming a loose fit (graphite would help but is horrendously messy) the tower will slide out under its own weight (or drag separate, which is FINE at this phase of flight.)

I do NOT think the 1/8” hole will significantly decompress the motor tube, so again assuming a loose fit for your rear deployment system, I don’t think this will compromise it.

not sure if this is not the most complex non-electronic rocket ever (especially since @JAL3 never completed the Rube Goldberg Lander, mores the pity!), but definitely one that would benefit from a preflight and launch checklist. I have encountered fecal turbine interaction on much simpler rockets where a checklist would have saved the day.

Well, the best-laid plans of rockets and men... thanks for taking the time to share your ideas @BABAR, sorry I changed horses mid-stream on ya.

Agreed on the benefits of a checklist.

I ended up gluing the tower ( via the alignment pin) into the hole in the Command Module. The 1/4" dowel is surprisingly stout, especially since I glued the 1/8" half dowels around the perimeter. Also made a boost protective cover out of some cardstock.

Guud Enuff.

 

[jqavins]

if 39 inches of fuse burns in 0.802 seconds, then isn‘t the burn rate 46.99 inches per second?

or 4.05 feet per second?

24 frames at 30 fps is actually 0.800 s even; 39 in ÷ 0.8 s = 48.75 in/s or 4.063 ft/s. But those third decimal place differences are utterly trivial.

 

[BABAR]

Well, the best-laid plans of rockets and men... thanks for taking the time to share your ideas @BABAR, sorry I changed horses mid-stream on ya.

Agreed on the benefits of a checklist.

I ended up gluing the tower ( via the alignment pin) into the hole in the Command Module. The 1/4" dowel is surprisingly stout, especially since I glued the 1/8" half dowels around the perimeter. Also made a boost protective cover out of some cardstock.

Guud Enuff.

View attachment 565717

Any chance you can attach the shock cord externally along the side of the stage let it fall horizontally? A bridle would be ideal. Cosmetically challenging……..

of course, as is if the ground is soft there is a good chance you will stick the landing!

 

[lakeroadster]

Any chance you can attach the shock cord externally along the side of the stage let it fall horizontally? A bridle would be ideal. Cosmetically challenging……..

of course, as is if the ground is soft there is a good chance you will stick the landing!

Yep...

And as to the ground here... well... there's a reason it's called "The Rocky Mountains"

I'm thinking that running the shock chord outside the Command / Service / Lunar Modules - 4th Stage and attaching it near the CG might be the smart move, maybe even a bridle attachment configuration. ​

 

[lakeroadster]

24 frames at 30 fps is actually 0.800 s even; 39 in ÷ 0.8 s = 48.75 in/s or 4.063 ft/s. But those third decimal place differences are utterly trivial.

I ran a program called "stopwatch" on my laptop... and video taped it. Then looked at it frame by frame to come up with the actual time.

 

[BABAR]

I'm thinking that running the shock chord outside the Command / Service / Lunar Modules - 4th Stage and attaching it near the CG might be the smart move, maybe even a bridle attachment configuration.


my bad, I thought you were just talking about the launch tower.

upper bridle attachment could be a loop around the base of the blast shield, hooked up just before insert fourth stage into three, hides behind the rocket for the PreLaunch Pad Beauty Shot photo and completely removed and tucked inside for display purposes.

 

[lakeroadster]

I'm thinking that running the shock chord outside the Command / Service / Lunar Modules - 4th Stage and attaching it near the CG might be the smart move, maybe even a bridle attachment configuration.


my bad, I thought you were just talking about the launch tower.

upper bridle attachment could be a loop around the base of the blast shield, hooked up just before insert fourth stage into three, hides behind the rocket for the PreLaunch Pad Beauty Shot photo and completely removed and tucked inside for display purposes.

I think a small eyelet through the side of the Service Module, at about the same location where the Service Module Reaction Control System (SM RCS) would be located, item 12 in the photo below.

That's above the CG of the 4th stage.

​