Sheri's Hot Rockets Saturn V

My next big project - and for me this is really big - is to build Sheri's Hot Rocket's 1/48 scale Saturn V.

Although Sheri flew hers on two G motors, I think I'll aim for a little bigger motor. The rocket, built per the instructions, weighs almost 10 pounds. Mine will probably weigh a pound or two more. So my plan is to put in a 54 or 38mm motor mount. For a first flight, an I200 motor looks like a reasonable choice. It's initial and average thrust are similar to the 2 G motors Sheri used, but the thrust duration is longer. I haven't run it through RockSim yet, but I'd guess it would fly 800 to 1000 feet on the I motor.

Since it's an almost $400 rocket kit and I'll be adding at least $200 worth of parachutes, paint, and other things (including my time!), I'm going to install an altimeter to eject the 'chutes at apogee and use the motor's ejection as a back up. It seems a wise investment.

I think I'll also add four 24mm (or 29mm) motor mounts around the center one. That way I could also ignite four D motors for effect. I'm not sure if they'd really add much but I like the idea of having five motors.

Sheri used three 60" 'chutes. I'm afraid of the two 'chutes for the bottom getting tangled, so I'll probably just use one larger 'chute for it.

I haven't actually received the kit yet, so I'm not sure everything I've suggested is doable or reasonable. But I'd appreciate any comments or suggestions.

-- Roger

Originally posted by jadebox
I think I'll also add four 24mm (or 29mm) motor mounts around the center one. That way I could also ignite four D motors for effect. I'm not sure if they'd really add much but I like the idea of having five motors.

-- Roger

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Put in 4 E9's ... they smoke pretty good... check out my scratch built NoName X4 with 4 of them...

www.plasmicinjection.com/vids/nonamex4.wmv

Good luck with your build and I'll try to hold back my envy

better yet, put a couple Apogee Long burn motors in the outboards... good luck on the build.

I'm currently working on a Apogee Saturn V which I've designed to be flown on H and *maybe* I motors. I've replaced all the internal components except the couplers. Those card stock centering rings are horrible..... Otherwise it is mostly built per instructions. Right now I'm finishing prepping it for paint (not nearly as easy as it sounds).

Sounds like a great project. As far as I know, everything should work, but I've never seen a Sheri kit. Post pics.....

I see that Sheri offers a 54mm MMT option... Imagine that thing on a K185... 8 second burn!!!

R

The cardstock rings might be stronger than you think.. Don't they have spars included in the kit for added strength?

I'm going to be starting my Sirius Saturn V pretty soon. It will have a 54mm motor mount and will use electronics. I am building it for Aerotechs K185, because it's just gonna look cool! It should weigh about 7 lbs. dry. I'll be checking this thread for suggestions.

Hey Roger,
Good Luck with your kit, it shipped out this morning, you should have it by the weekend!!!!
Sheri

Originally posted by SpartaChris
The cardstock rings might be stronger than you think.. Don't they have spars included in the kit for added strength?

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They do have spars....

The problem is that the card stock starts peeling apart. Also, the strength of the glue joint between the spars and the centering ring is limited by the strength of the glue holding the layers of paper in the card stock together, since even penetrating glue fails to soak in past the first layer or two. I'm sure they work fine for G engines, but definitely not for high power engines.

I ended up not using any, (even when they weren't load bearing) since they drove me nuts. Neither CA, wood glue, or epoxy managed to resist the combination of peeling and flexing. The rest of the kit is great, I just hate the card stock components.

Anyway, I've already built it with plywood centering rings an bulkheads.

Roger,
My SATV kit has 1/4" ply centering rings, you shouldnt have any of those issues.
Sheri

Originally posted by Nathaniel
I ended up not using any, (even when they weren't load bearing) since they drove me nuts. Neither CA, wood glue, or epoxy managed to resist the combination of peeling and flexing. The rest of the kit is great, I just hate the card stock components.

Anyway, I've already built it with plywood centering rings an bulkheads.

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Just watch your CP/CG relationship. You've made changes that will add a gob of weight to the rear. I cringe to think of how much weight it's going to take to offset that.

FWIW, my experience with the Apogee rings didn't match yours -- the paper layers stayed together quite nicely. I wonder if maybe the die was dull when yours were cut, and maybe it just crushed the paper, instead of cutting through properly?

-Kevin

Originally posted by bigone5500
Put in 4 E9's ... they smoke pretty good... check out my scratch built NoName X4 with 4 of them...

Good luck with your build and I'll try to hold back my envy

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Thanks.

I said D's, but would probably need to use E9-6s to ensure that the ejection charges don't go off until after the altimeter has deployed the 'chutes at apogee.

-- Roger

Originally posted by sheri
Hey Roger,
Good Luck with your kit, it shipped out this morning, you should have it by the weekend!!!!
Sheri

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Thanks again. I feel like a kid waiting for Christmas.

I'm very excited about building this kit. I'll, of course, post photographs as I build it. I have one other project to get out of the way (my upscale Omega) before I can really dig my teeth into the Saturn V. But I'll start gathering the parts I need for the modifications soon and doing some work with RockSim.

-- Roger

Originally posted by TeenRocketNerd
better yet, put a couple Apogee Long burn motors in the outboards... good luck on the build.

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I'll run all this through RockSim when I get the files (Sheri includes them with the kit).

But my "back-of-envelope" calculations (i.e. guesses) are that E9-6s will work. The I200 has about a 1.75 second burn. I doubt the optimum delay will be longer than six seconds. So the E9's should still be burning their delay elements when the altimeter deploys the parachute.

In the (unfortunatey quite likely) event that the E9s ignite before the main motor, the timing might be close, though. I could rig up some way to ignite them after the main motor, but that would add a lot of complexity.

My goal is to actually fly this thing, not leave it as a display model like my Estes Saturn V I built about ten years ago and have no intention of flying.

-- Roger

If you are planning on using electronics, why not install a timer as well? Then you can airstart the E9's easy enough about .5 seconds after ignition of the I. It is slightly more complex, yes, but easily do-able.

Originally posted by SpartaChris
If you are planning on using electronics, why not install a timer as well? Then you can airstart the E9's easy enough about .5 seconds after ignition of the I. It is slightly more complex, yes, but easily do-able.

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I'm tackling a lot of new things with this project. I've built an ebay for dual-deployment of my Level 1 rocket. But I've never used it yet. And I've never air-started any motors.

But ... I'm planning to use motor ejection as a backup to the altimeter. I'm not planning to use dual-deployment. And if air-starting of the outboard motors fails, it wouldn't have any practical effect on the flight. So I may try it. There's certainly plenty of room in an eight-inch body tube to do something like that.

(Please don't mention that if I every got really daring in the future, I could airstart some larger motors.)

-- Roger

OK, I won't mention that if you manned up and went with 29mm outboards, you could airstart some G's and H's.

Yeah, no harm in trying it out. I think 29mm motors will be easier to airstart than 24mm, but it's all possible.

COOL! I am all for Saturn V's I am working on a small 1/96th (doing plans and scaling now) with a 29mm central and 4 24mm And if it all goes right a 2nd stage. (maybe 3rd if it balances right ) One thing to keep in mind is if those outboards don't light you have that extra weight in the rear. You can compensate that by adding extra noseweight or get a LEUP and use dipped E-matches. Just thought I would share some knowledge

thanx, Ben

Dipped E-matches? For E9's?

Originally posted by cjl
Dipped E-matches? For E9's?

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I was referring if he went with 29mm outbaords.

thanx, Ben

Originally posted by cjl
Dipped E-matches? For E9's?

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Got any recommendations for airstarting BP? I'm flirting with the idea of a pair of 9V NiCd's through a PerfectFlite timer and just using the stock Estes igniters. (of course, I'm trying to airstart 6 at a time, though) Should have enough zap.

Yeah, now that ematches are getting to be almost as expensive as a larger BP motor, it's questionable, unless you're soldering and dipping your own...

-Ken

Honestly, if you can keep them from shorting, the estes igniters should work fine. That's what I would try first.

Originally posted by new2hpr
Got any recommendations for airstarting BP? I'm flirting with the idea of a pair of 9V NiCd's through a PerfectFlite timer and just using the stock Estes igniters. (of course, I'm trying to airstart 6 at a time, though) Should have enough zap.

Yeah, now that ematches are getting to be almost as expensive as a larger BP motor, it's questionable, unless you're soldering and dipping your own...

-Ken

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I did a test the other night and a normal E-math tapped in the nozzle (use wadding with tape overtop of it) will ignit a D12 and C6 (the 2 motors I tried) so I would suspect a E9 would be no different.

thanx, Ben

Yes, but E-matches are expensive and getting harder to obtain.

Originally posted by ben
COOL! I am all for Saturn V's I am working on a small 1/96th (doing plans and scaling now) with a 29mm central and 4 24mm And if it all goes right a 2nd stage. (maybe 3rd if it balances right )

Click to expand...

That sounds like quite a project. It sounds like the motors might be larger than the rocket.

I have the 1/70 scale Estes Saturn V which I built about 12 years ago. It's what really got me back into rocketry after a twenty-year break. I haven't flown it. I did, however, buy another kit which I plan to someday build and fly.

One thing to keep in mind is if those outboards don't light you have that extra weight in the rear. You can compensate that by adding extra noseweight or get a LEUP and use dipped E-matches. Just thought I would share some knowledge

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Actually, you have the extra weight even if the outboard motors do light. They just get lighter after a few seconds.

In my case, the rocket will weigh about 10 to 12 pounds. So the weight of a few motors won't make much difference. And I'll have the original RockSim file so I can compare the CG of my version to the CG of the original and make sure it doesn't move back.

I did a little research today (beats working) and was reading about the PerfectFlite miniTimer3. It should be able to handle firing four Estes igniters. I'll have to use something other than a nine-volt battery, but there should be plenty of room in the rocket.

-- Roger

It's a good day when you come home from the office and find a box like this on the porch:



More photos at: 1/48th Scale Saturn V

-- Roger

To hell with getting a photo with you next to the box, rip it open \
jk. got to get some photos to remember that by , just dont forget construction photos

now sheri is giving out girls!! I SOO need to get me one

Looks good!

thanx, Ben

Originally posted by jadebox
It's a good day when you come home from the office and find a box like this on the porch:

More photos at: 1/48th Scale Saturn V

-- Roger

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Great Roger, I am glad you got it safely!!!!

Nice Photos!!! I like the wife's necklace!!!

Originally posted by Chrisn
To hell with getting a photo with you next to the box, rip it open \
jk. got to get some photos to remember that by , just dont forget construction photos

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The in-the-box pictures are at:

https://www.payloadbay.com/gallery/v/projects/saturn-v/

I've started reading the instructions. The 8.5 x 11" manual is about a half-inch thick. This definitly isn't a Skill Level 1 project.

I've already decided to read the instructions several times before I start building it. The first step looked daunting until I read ahead and saw how the part is used later.

The first thing I'm going to do is play with RockSim and maybe start working on making some new centering rings. I didn't specify which power option, but I'm planning to cut new rings anyway. They're big enough that I think I can do an okay job without having to find someone with a laser cutter.

Of course, I'll post more pictures when there's something interesting to see.

-- Roger

Originally posted by sheri
Great Roger, I am glad you got it safely!!!!

Nice Photos!!! I like the wife's necklace!!!

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The kit's actually my wife's, so she can do with it as she wishes. But I asked her if I could build it and she agreed. I think I'll keep her.

-- Roger