Multi Stage Saturn V

[Daddyisabar]

I'll email NAR and ask for clarification on the 80 Newton maximum.

Sometimes it is better to bend the rules for more power to be safe, especially when dealing with a super complex rocket that is way outside the box. The Top Men will understand and they are more forgiving than myself. Maybe do your Level one flight first.

What is most important is that you have distance and an experienced fire/recovery crew on hand. A little snow on the ground or wet Springtime grass would be good if you launch from a Rocky Mountian High, Colorado.

Consider doing a poll thread when your plans are build ready. Ask the forum rocket scientists will it work? The answers being Yes, As Is, Yes, but only with My brilliant modifications, and No, grab the kids and run for the bunker!

 

[Daddyisabar]

My new computer rocks, it's got the clocks, but it was obsolete before I opened the box....

Your Rocsim is a disaster. You're waxin' your rocket, tryin' to make it go faster!

 

[boatgeek]

It's all about the Pentiums baby! They call him the king of the spread sheets. Got 'em printed out on his bed sheets....

If you ask the Pentium to do the math, you'll end up with 11.99999999 motors installed in that thing. You have to be really old to get that joke.

This is definitely not a dry grass day kind of rocket. Snow or recent rain are your friends.

 

[Daddyisabar]

If you ask the Pentium to do the math, you'll end up with 11.99999999 motors installed in that thing. You have to be really old to get that joke.

This is definitely not a dry grass day kind of rocket. Snow or recent rain are your friends.

I upgrade my system twice a day. I'm strictly plug and play. I ain't afraid of Y2K!

 

[techrat]

If you ask the Pentium to do the math, you'll end up with 11.99999999 motors installed in that thing. You have to be really old to get that joke.

I must be really old, because the Pentium 90 floating point error seems like yesterday.

 

[Daddyisabar]

Look kid, I've been to rocket launches from one side of this State to the other, seen lots of strange things. But never have I seen an all powerful spin stabilizing force on a Saturn V model rocket using tiny canted fins.

I've always been a huge advocate of large, traditional, straight fins on the bottom. Keep the fins and motors on the bottom of the rocket where they should be! I don't think anyone would question some oversized fins on a Saturn V first stage. I like big butts and I can not lie. Or some pop out fins or Sputnik like conduits on the second stage. It would still look good. Why, I would even settle for some venting steam fins on the upper stages, shaped like the steam coming out of the nose of the horse on the retro logo of our beloved Denver Broncos.

Unless you have a center line launch lug how can you properly spin you rocket off the pad? Monocopters and canted motor saucers rule!

I've built and flown the canted finned Estes Sidewinder and it is kinda a P.O.S.

Nothing beats having a good blaster at your side. Always shoot first!

 

[lakeroadster]

But never have I seen an all powerful spin stabilizing force on a Saturn V model rocket using tiny canted fins.

Thus, the method to my madness. Roads less traveled.​

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Actually, the fins on my version are to scale for the rocket... just canted. I've mentioned before that I truly hate scale model rockets with oversized fins. I understand why folks build them that way... but that doesn't mean I have to also partake in the blasphemy.​

I would even settle for some venting steam fins on the upper stages, shaped like the steam coming out of the nose of the horse on the retro logo of our beloved Denver Broncos.

#TheNFLSucks​

 

[Daddyisabar]

Thus, the method to my madness. Roads less traveled.​

​

Actually, the fins on my version are to scale for the rocket... just canted. I've mentioned before that I truly hate scale model rockets with oversized fins. I understand why folks build them that way... but that doesn't mean I have to also partake in the blasphemy.​

#TheNFLSucks​

The mere sight of an oversized fin and the first stone will be cast to smash the true scale blasphemy!

How about building a rack down from the second stage to hold the fin units. The first stage would eject and the lovely fins would stay on the second stage. The rack would look like conduits so maybe not so bad. It would get hibachied and likely break on landing, but it wouldn't look terrible and provide greatly needed stability (drag and "continued spin") for the second stage. A disposable fin rack for each flight.

My spicy force visions are not aligning with your machines on upper stage stability. I know I should be canceled for not trusting the machines. Maybe I just need to go mindsim on IX, many machines on IX.

 

[lakeroadster]

The mere sight of an oversized fin and the first stone will be cast to smash the true scale blasphemy!

How about building a rack down from the second stage to hold the fin units. The first stage would eject and the lovely fins would stay on the second stage. The rack would look like conduits so maybe not so bad. It would get hibachied and likely break on landing, but it wouldn't look terrible and provide greatly needed stability (drag and "continued spin") for the second stage. A disposable fin rack for each flight.

My spicy force visions are not aligning with your machines on upper stage stability. I know I should be canceled for not trusting the machines. Maybe I just need to go mindsim on IX, many machines on IX.

Let's see, 7-Up'r stage motors, and the stages don't have fins? I am reminded of a phrase from an old time commercial: Never had it, Never will.

The mission is to scratch build a Saturn V rocket that has:

• the appearance of the real thing,
• the same number of stages as the real thing,
• the same number of motors in each stage as the real thing.

No "Mission Drift" by the designer, the builder, or the popcorn gallery shall be tolerated.

 

[BABAR]

Let's see, 7-Up'r stage motors, and the stages don't have fins? I am reminded of a phrase from an old time commercial: Never had it, Never will.

The mission is to scratch build a Saturn V rocket that has:

• the appearance of the real thing,
• the same number of stages as the real thing,
• the same number of motors in each stage as the real thing.

No "Mission Drift" by the designer, the builder, or the popcorn gallery shall be tolerated.

Hopefully you can get the other classic Saturn V line dialed in, “Failure is not an Option.”

 

[Daddyisabar]

Let's see, 7-Up'r stage motors, and the stages don't have fins? I am reminded of a phrase from an old time commercial: Never had it, Never will.

The mission is to scratch build a Saturn V rocket that has:

• the appearance of the real thing,
• the same number of stages as the real thing,
• the same number of motors in each stage as the real thing.

No "Mission Drift" by the designer, the builder, or the popcorn gallery shall be tolerated.

I will repent. Mixing up a highball 7 and 7 using some old 7 UP containing lithium citrate. That will surely help my old dude crankyness.

Caffeine really does me in, a surefire way to a headache if not regularly ingested. Caffeine: 7 Up, never had, never will. Lithium citrate...not so much.

A pilgrimage to the site of the old 7 Up bottling plant off of Santa Fe Drive is in order for this ole oddroc Blasphemer! I will put three old 7 Up bottles on the fingers of one hand, clang them to gather calling out "Warriors, come out and play!" Just like the classic sceen from the 1979 cult film The Warriors.

Stay brave and strong with no mission creep, just like NASA in the old days. Ignore the politicians and special interests. Like Frank Sinatra, Chairman of the Board, sang out so beautifully; "I did it my way!"

 

[lakeroadster]

Updated 12-29-2022: See Post 188

 

[lakeroadster]

Updated 12-29-2022: See Post 188

 

[lakeroadster]

And here's the simulation with the correct motors.

 

[boatgeek]

I love that this simulation has so much going on that it needs 9 lines of keys below.

 

[jqavins]

If you ask the Pentium to do the math, you'll end up with 11.99999999 motors installed in that thing. You have to be really old to get that joke.

This is definitely not a dry grass day kind of rocket. Snow or recent rain are your friends.

Who are you calling old? Oh, wait, I am.

 

[BABAR]

And here's the simulation with the correct motors.

View attachment 551793View attachment 551792

not an Open Rocket user (sorry @neil_w , when it works easily for rectangular cross sectional rockets maybe I will jump in), but I am guessing the slope of the blue lines relates to the descent speed of the various stages.

looks like three and four come in pretty hot compared to one and two. I guess that is due to streamer recovery.

suspect the sim is accurate, just seems weird that the upper stages are touching Terra (often far too) Firma 15 seconds from ignition, while stages one and two are a bit more leisurely. the upper stages are going to be obviously far lighter, and maybe will handle the impact speed better than the heavier booster sections. And likely design will keep the smaller stages impact landing zone closer to pad, IF the trajectory remains near vertical. So may be a good thing.

i had a cloned Edmonds’ CiCi2 that was pretty vertical for 3/4 of booster flight, then for some reason seemed to decide on last fraction of section to weathercock nearly 90 degrees at separation, recovered the booster, never laid eyes on the sustainer after the stack lifted off the rod.

and that was only two stages.

 

[BABAR]

Okay, fine print.

“in the event that the chute deploys at 3rd-to-4th stage separation……”

so three options for stage 3?

1. Chute deploys immediately at staging (while at or near MaxV? That will be……interesting. Been dere, done dat, immediately converted a chute to a surprisingly effective streamer.)
2. Chute deploys at apogee (ideal, but I only see one motor which is zero delay and lights last stage, so what prompts it to come out at just the right time?)
3. Chute doesn’t deploy and stage tumble recovers (don’t think it’s gonna be stable, so shouldn’t come in ballistic, and tumble recovery is actually the most COMMONLY used booster recovery technique so may be fine. Is this the assumption of the simulation displayed here?)

 

[neil_w]

not an Open Rocket user (sorry @neil_w , when it works easily for rectangular cross sectional rockets maybe I will jump in)

No skin off my nose.

Seems silly to me to shun a good free tool, but your choice of course.

 

[lakeroadster]

..... looks like three and four come in pretty hot compared to one and two. I guess that is due to streamer recovery.

suspect the sim is accurate, just seems weird that the upper stages are touching Terra (often far too) Firma 15 seconds from ignition, while stages one and two are a bit more leisurely. the upper stages are going to be obviously far lighter, and maybe will handle the impact speed better than the heavier booster sections. And likely design will keep the smaller stages impact landing zone closer to pad, IF the trajectory remains near vertical. So may be a good thing.

Thanks for adding your thoughts.​

Look at the design of stages 3 and 4 you'll notice they are both very durable, as I like to say hell-for-stout. I plan to attach the streamer to the capsule at the base of the tower, so the motor end of stage 4 ground hits first and not the tower.​

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1st and 2nd stage parachutes are designed for ground hit speeds of less than 15 fps.​

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3rd and 4th stage streamers are really only for aid in tracking, in the air and on the ground. Due to space limitations for the streamers, both of these stages will indeed as you state be coming in pretty hot.​

I only see one motor which is zero delay and lights last stage, so what prompts it to come out at just the right time?

Look again. There is a 1/4A3-3 in the 4th stage.​

3. Chute doesn’t deploy and stage tumble recovers (don’t think it’s gonna be stable, so shouldn’t come in ballistic, and tumble recovery is actually the most COMMONLY used booster recovery technique so may be fine. Is this the assumption of the simulation displayed here?)

The simulation shown assumes the 4th stage chute streamer deploys near 4th stage apogee, and not at stage separation.​

​

If I set the simulation to deploy the streamer at stage separation the 4th stage apogee is below the 1st / 2nd stage apogee.​

 

[lakeroadster]

I'm pretty sure the "No more than 80N average thrust" rule is per motor. At absolute worst, it would be per stage. That should let you replace the A8 with a C11 or possibly a D12 and still be under all the limits.

Thanks. I ran the Open Rocket simulation in the configuration shown in the spreadsheet, the rocket is still above 30 mph off the rod, so the A8 keeps the rocket from leading into a deep dive conversation in regard to compliance interpretations.

But I'm leaving the motor tube a 24mm...

That's fair. Once you get your L1, you can load up to 125g propellant and 1500g pad weight and still be Class 1 all legit.

Isn't the 30 mph off the rod (or most beautiful rail) a rule of thumb based on the assumption you are a launching a decent, safe, approved, traditional 3-4FNC rocket? Not some cluster staged, sport scale, spin finned abomination. So says my sweet sassy molassey inner RSO...an angel on my shoulder.

Then the little oddroc scum devil appears on my other shoulder and says to power it up on the first flight. Nothing worse than and under powered oddroc crashing do to lack of thrust. Go away little scum devil, I am a good boy!

I'll email NAR and ask for clarification on the 80 Newton maximum.

@boatgeek and @Daddyisabar​

​

I received a reply back from NAR and as @Daddyisabar speculated the 80 Newton Max Thrust specification by NAR for a non HP rocket is indeed a "per motor" specification.​

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So for clusters as long as none of the motors do not exceed 80 Newtons those specific motors are acceptable.​

​

The driving NAR requirement for this Multi Stage / Multi Clustered Motor design therefore is:​

A Maximum Total Propellant Weight of 125 grams, and,​

A Maximum Rocket Weight of 1,500 grams (53 ounces).​

I've changed the design to have (3) C11-3's and (2) D12-0's for the 1st stage. That extra C11 gives the rocket more kick off the rail.

I also noticed I didn't have the correct rod length in the simulation? I corrected that and the simulated speed off the rod is now 45 mph. And that B Guud'r.
Thanks to both you fella's for sticking with me on this design. You're tutelage is sincerely appreciated.

 

[BABAR]

Okay, I didn’t read the fine print well enough, I was thinking your were talking the THIRD stage wouldn’t deploy immediately. I think STREAMERS are okay to deploy from boosters at separation, simply BECAUSE they aren’t as effective as chutes. As I have said from experience, deploying chutes for boosters AT separation velocity is……not optimal. Some elastic in the shock cord won’t hurt either, as long as you have good wadding protecting the elastic from the ejection charges.

Also whereas I usually FOLD streamers up to the last few folds before ROLLING them for single stage rockets where I WANT the streamer to completely deploy immediately, this may be a case where a bit of rolling for that THIRD stage may allow the stage to decelerate before full streamer deployment, which may be good.

I LIKE the change to three C11-3 and 2 D12-0s on first stage. It DOES give you redundancy.

2 zero delay motors, probability is very high that BOTH are gonna work, but if only one works, it will still light off the second stage. It also simplifies your manifold, as you only need to duct the two D12-0s to the next stage, instead of original three.

how are you gonna handle the ejection charge from the midline C11?.

Your D12-0 dual manifold is directly in front of it, so not gonna be easy to attach a chute (not that you need one.)
options I can think of (in other words, strongly suspect there are more and possibly better ones than listed here.)

1. Assuming field rules allow, by far easiest solution is eject it, in which case I would go with C11-0, if you are gonna dump it, dump it early, drop the mass, and take the extra bit of acceleration as a bonus.

2. duct it out the back.

3. Plug it. This will however prevent you from flying it at a NAR (and maybe Tripoli… @Steve Shannon ??) event. It also maaaaaay void your NAR insurance, as even though it may be the safest option by far, it is a violation of safety code

“2. MotorsI will use only certified, commercially made model rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer.”



i will trust your Open Rocket Sim that dropping to C11-3s helps you get off the pad better, seems like D12-3s would work better but does give you high first to second staging altitude, which I agree is not best, at least for first flight.

https://www.rocketreviews.com/compare-estes-d12-to-estes-c11.html
have you run any sims on what happens if one or more of cluster motors doesn’t light? If neither D12 lights, upper stages won’t light and you will have a three stage ballistic return. Not good, especially For the rocket, but assuming a heads up launch, big rocket coming down from low altitude should be easy to see and avoid. More worrisome is if insufficient motors light, i.e., enough thrust to get off the rod but not enough to be Stable, in which case you have a good chance of a significantly non-vertical staging event, resulting in a rapidly spinning three or four stage cruise missile and/or landshark.

@aerostadt here in post 7 says using putty to hold in igniters greatly improved his cluster success
https://www.rocketryforum.com/threa...-ignition-for-2-estes-ds.169194/#post-2198887

 

[BABAR]

Rethinking ducting, especially with only two zero delay motors on stage one and using fuses.

put TWO fuses in each stage 2 motor, and have STRAIGHT motor Mount tubes off each zero delay stage 1 booster motor, have one set of fuses to each tube. No angling or combining of tubes required, essentially no manifold.

i am ignorant On fuses, can you attach them with putty to the second stage motors (you DO have a G-Force problem holding ANY igniter in place, I am sure the high power guys have all sorts of techniques for that.). But do fuses need air to burn (I.e., if you hold them in with wadding, putty, or even plastic plugs, do they work and will they stay in place?)

 

[lakeroadster]

how are you gonna handle the ejection charge from the midline C11?.

The 1st stage will be detached from the 2nd stage, and tumbling, when the C11 ejection charge fires. The ejection charge will blow right through the staging tube... no worries.​

have you run any sims on what happens if one or more of cluster motors doesn’t light?

If one of the 5 24mm motors doesn't light, it still clears the rod at over 30 mph. Perhaps I'm just over confident, but I've launched my F-79 twice (it's a dual motor D12) and my Mercury Abort LES (it's a triple cluster D-12) using e-matches with no misfires. I've used the e-matches also for single motor launches and thus far have never had a failure with an e-match.​

​

Rethinking ducting, especially with only two zero delay motors on stage one and using fuses.

put TWO fuses in each stage 2 motor, and have STRAIGHT motor Mount tubes off each zero delay stage 1 booster motor, have one set of fuses to each tube. No angling or combining of tubes required, essentially no manifold.

The single central staging tube works well with packing the parachute.​

i am ignorant On fuses, can you attach them with putty to the second stage motors (you DO have a G-Force problem holding ANY igniter in place, I am sure the high power guys have all sorts of techniques for that.). But do fuses need air to burn (I.e., if you hold them in with wadding, putty, or even plastic plugs, do they work and will they stay in place?)

I'm going to follow @heada 's advice.

​

In the motor, I expose 1/4" of the match inside and put that into the motor nozzle. That is secured with an Estes plug if there is room and if not, a wad of wadding and masking tape over the nozzle. For the booster ejection end, similarly expose 1/4" of the match and bundle all of them together with the exposed ends into the ejection area. That is then secured with masking tape.​

I'm planning to do a bench test using a BP motor and fuses running through a staging tube to a 24 mm BP motor. I'm really wanting to see what's left of the fuse. @heada also discussed this below:​

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Yes, 5 individual sections of fuse. At the booster end they were bundled together so that the booster motor ignited them all. Tied together with cotton kite string.​

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The fuse gives off almost no sparks/flames when burning inside the paper shell but it burns so fast you almost can't tell. To protect the fuse from one of the non-booster motors and to protect everything else from the fuse, I wrapped them in aluminum tape.​

​

Starting from the C6-0, 5 sections of fuse with 1/4" of the insides exposed. All tied together into a bundle with thin cotton kite string and then a wrap of aluminum tape. The end of the bundle is not secured to the booster motor so that each stage can be prepared separately but the bundle fits down into the booster MMT freely. Up about 2 inches, the bundle split apart inti their individual fuses. Again wrapped in aluminim tape and leading up to the 5 motors in the next stage. Fuse ends were expised 1/4" and inserted into the nozzle and secured with the soft plastic nozzle plug and then taped over with aluminum tape.​

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When I did a test burn of the fuse in my backyard, I waved my mapp gas torch over the end and in what I can only explain as nearly magic, the 1ft section disappeared before I could prepare myself. If you've ever used green fuse on fireworks, this is absolutely nothing like that at all. It is much more like a pile of 4Fg BP that you toss a match into. Its there and then not. No sparks or flame, just fuse and then paper bits. Even assuming the 0.4 sec per foot, the 5inch sections burn in 0.17sec If its the fast version the 5inches burn in 0.04sec. 40msec!​

 

[Steve Shannon]

3. Plug it. This will however prevent you from flying it at a NAR (and maybe Tripoli… @Steve Shannon ??) event. It also maaaaaay void your NAR insurance, as even though it may be the safest option by far, it is a violation of safety code

A Tripoli member at a Tripoli launch could probably plug it. I cannot speak for a NAR member.

 

[BABAR]

I am still lost at stage 1 as of post 163. There you have all 5 motors first stage motors manifolded/ducted to a central tube.

what is pushing the chute(s) out of stage 1 after staging if all motors are ducted to the central staging tube?

I had assumed you had two (or three) zero-delay first stage motors ducted to the fuse, and reserved the three (or two) positive-delay motors for the chute(s), easy enough (if a bit tight) for the outboard positive-delay motors to just each pack a chute in STRAIGHT motor mounts above the motors. The centerline motor I don’t see as useful for a chute either centrally ducted with the zero-delays or not.

 

[BABAR]

I appreciate your patience with me on this thread. I also do not understand the purpose of the vent holes in the manifold.

 

[jqavins]

i will trust your Open Rocket Sim that dropping to C11-3s helps you get off the pad better, seems like D12-3s would work better but does give you high first to second staging altitude, which I agree is not best, at least for first flight.

https://www.rocketreviews.com/compare-estes-d12-to-estes-c11.html

I had exactly the same thought on the D12 vs. C11 for rod exit speed (and even had the same graph, but from ThrustCurve, ready to paste in.). Mongo not understand.

If one of the 5 24mm motors doesn't light, it still clears the rod at over 30 mph. Perhaps I'm just over confident, but I've launched my F-79 twice (it's a dual motor D12) and my Mercury Abort LES (it's a triple cluster D-12) using e-matches with no misfires. I've used the e-matches also for single motor launches and thus far have never had a failure with an e-match.​

I love this paragraph. Your experience shows that the chance of ignition failure is very low, and you've also verified that things are OK if one motor does fail to light. I salute your caution in the face of very good odds.​

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I'm planning to do a bench test using a BP motor and fuses running through a staging tube to a 24 mm BP motor. I'm really wanting to see what's left of the fuse. @heada also discussed this below:​

Good old green visco fuse (cannon fuse), which is too slow for this application, is coated and should be waterproof. And I'm 99% sure it doesn't need air to burn. So it should burn under water. I say all that to lead to this: I'd bet heavily that the fuse you're using also doesn't need air, and while you're ground testing, I'd be very curious to see how it does under water (if you would be so kind as to indulge me).

 

[lakeroadster]

Mongo only pawn in the game of life​

​

I'm using (3) C11-3's (and (2) D12-0's) because the total motor propellant weight can't exceed 125 grams. The current configuration is 118 grams. And, the 1st stage simply doesn't need any more thrust because:​

​

The mission for this rocket is to:​

• have the same number of motors and number of stages as the real Saturn V,
• have a safe, stable, yet relatively slow initial launch,
• have staging occur at a relatively low altitude so it can be seen by spectators, and
• recover all four of the stages.

Good old green visco fuse (cannon fuse), which is too slow for this application, is coated and should be waterproof. And I'm 99% sure it doesn't need air to burn. So it should burn under water. I say all that to lead to this: I'd bet heavily that the fuse you're using also doesn't need air, and while you're ground testing, I'd be very curious to see how it does under water (if you would be so kind as to indulge me).

Do a separate test, while video taping, with the fuse hanging into a clear glass of water, and light the fuse with an e-match...​

​

Would that work for ya?​

This fuse burns so quick I'm not sure it'll be very spectacular... but I'll be more than happy to "burn one" for ya, Joe. ​

 

[GlenP]

Here's the updated drawing set,...

Really nice CAD drawings. Do you ever make 3D printable models for any of your parts, or just make everything with traditional methods and materials for your rockets? I used to do some CAD stuff at work, but never got CAD software for my home Mac computer. It would be neat to try making some 3D printed parts, our library here has a 3D printer available now.

One idea to consider, is for testing out portions of the cluster ignition and staging one stage component at a time, although this is more costly in the number of motors and materials along the way. This kind of follows the concept of the old Apollo days where you test a rocket with a dummy equivalent payload similar in weight/c.g. - i.e. a boilerplate model. For example, test the first booster cluster stage with a sustainer that is just an empty weighted portion to mimic the remaining stages but maybe with one motor and chute. Then, do a two stage cluster with a smaller boilerplate simplified third stage sustainer. The series of mock-up boilerplates is just a suggestion for a flight testing approach to validate the design concepts one at a time so that you can incrementally build on each flight-tested proven design. Just an idea, I think your designs, drawings, and sims are pretty well thought out.