Saturn V mods

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Feb 2, 2009
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At Sandman's suggestion, I've decided to start a thread on my latest project. It's time to start the Estes Saturn V (it's only been sitting on my workbench since last fall)!

Of course, it's not going to be built stock. What fun would that be? After debating the value of clustering vs. a big motor, I'm going for the BIG MOTOR. Well, big for an Estes kit at least. The plan is to install a 29mm motor mount and fly it on F20 Econojets or E16 RMS reloads. I've already got the motor tube and plywood centering rings.

Here's what else I'm kicking around. Everyone's thoughts are much appreciated:

Cast resin fin shrouds & nose cone from Moldin' Oldies.

Foam filled 3rd stage and LM transitions (adds strength, and weight up front). Either that, or soak with CA. Also may get some sheet styrene to add detail to the LM transition.

Foam between centering rings - how? I'd like to do this, but with three rings it seems that either the front or aft end of the MMT will have to be left empty. Which end is more important?

Internal launch lugs - how complicated if I foam the body tube?

Modeling clay or epoxied fishing weights in the nose. How much? I plan to fly it with the 4 outer engine bells attached - the 5th will be replaced by the MMT. How far should I extend the MMT to keep from melting the engine bells?

What to use for adhesives and paint? I'm figuring 15 min. epoxy for major structures, and 3M spray & CA for wraps and stuff.
Maybe with the internal launch lugs you could coat the rod you'd be using with Vaseluine or something to prevent the foam from sticking to it...

Maybe you could use one of the long (10 inch?) lengths of launch lug material to pass through the bay where you will be adding foam. Get the LL positioned where you need it, glue & seal the ends, then add the foam last?

That eliminates the need to drill 'blind' through a block of foam and hope the other end of your drill bit emerges where you need it, the whole time risking ruining the assembly you sunk so many hours into.
Well, I wasn't planning to work it that way.
My thinking was to pre-drill the CR's, then epoxy the two forward rings in place with the lug run through. Once they're glued into the main tube, I'd pour the foam then mount the aft ring.
My biggest concern is preventing ejection gases from going places I don't want it. If this doesn't work then I'm going to mount the lugs on the outside but beef up the standoffs - maybe build up a wedge-shaped mount from basswood.

Do you guys think foaming the body tube is a good idea or is that overdoing it?
For an internal launch lug you can use a Totally Tubular T-2 or T-3 tube (1/4")

They come 34" long too!

I want to see this built!

That's a good idea sandman! That way, Chilly, you could insert your internal launch lug, glue it to each CR, then when you foam the fin can area, just insert a 1/4" launch rod into the internal lug to keep the foam from crushing it.

I'm just opening my Saturn V as well. I bought it about a year and a half ago, but sidelined building it because I didn't feel my skill level was up to a level where it would do the Saturn V justice. I haven't overbuilt many models just yet, but I'm sticking with the 24mm motor mount, with the aspirations of using an Aerotech F21 (and some reloads) somewhere down the road. I'll be watching this thread closely, and post a few pictures here and there, but considering I'm outranked in experience by most of the guys here on TRF, I'll be doing a lot of watching! =) With that being said, my rocket room is gonna be a mess for the coming month or so!
I had planned on doing the same thing, until I found that F21s can be hard to find and E15s may be discontinued. Sandman suggested a 29mm mount and using F20s, which made more sense as I thought about it. If I keep it light enough, it would also fly on an E16 RMS in small I still may not foam the body tube, just to keep weight down. I do use foam, it'll be between the middle and aft CR's only.

When the extra parts arrived from Magnum last week, the 1/4" launch lug was six pieces! I thought it would be one long piece. I may put them on a launch rod and tape them together, then soak the tape with CA. Think that'd work?
I was fortunate enough to stash a few F21s away for safekeeping. They were snatched up pretty quick! I also have the 24mm Aerotech RMS hardware, hence the decision, besides, . I like the taped-up launch lug idea. It'll make it a little thicker in the wall, and if you're going the internal lug route, mebbe it'll be a bit more heat-resistant. I started building my motor mount last night, although tonite I won't make any headway tonite since this is a Duke/North Carolina basketball game night. Anyways, happy building! :)
Boy do I miss ACC hoops. The Big 10 just ain't the same.
Two more cents on the Saturn V....

I chose to go the cluster route and so far it's been a success. My first test flight (to make sure it was balanced properly) was with 3 D-12's and it looked like it got somewhere around the predicted altitude of 400 ft. Next up will be E series motors which should send it to 1,500 -2,000 ft. - about the same as with a single F motor.

Obviously mine isn't stock either. At the bottom end I filled the fins with balsa, soaked them with CA and then put the two sides together. I also covered the insides of the fairings with epoxy for a little extra strength. After three landings - no dents.

For recovery I'm using one large 28" chute, with the top section attached in the same bridle config as the stock model. But I enlarged the chute bay to accommodate the larger chute and shock cords. To pop the chute, I put a tube (lined with aluminum foil) from the top of the MM to the bottom of the parachute bay which is used to collect the ejection charge in a smaller area than the main BT. At the top of the tube is a balsa funnel into which goes a plug that has a 1/8" bulkplate on top. When the ejection charge goes off, the gas expands, pushes the plug and bulkplate up and pops the nose section and chute. No need for wadding - nothing gets burned or melted.

I left the top sections alone (no foam, etc) cuz it lands softly and is not damaged after the heavier bottom section has landed.

I love this rocket - this is my third Estes model and I'll probably make another. I don't have any pic's of this one but attached is a pic of my scratch built 5.5" version I made a few years ago.

Good luck with your project,
Nice looking Saturn V, Leland. I've also thought about building another Saturn V (if this one turns out well) with the 4 x 18mm cluster like there was back in the heyday, which was before my day. I've got a nie 36" chute BTW, I'll be using it on the Saturn V one completed. I've got some 400# kevlar I want to use for the shock cord. Hopefully that will be durable enough over the test of time.

Chilly, I was born in Iowa. I loved the Hawkeyes. I moved to down here and practically forgot all about the Big 10. Hopefully ESPN or Fox will broadcast the ACC Tournament for ya! :D

Back to rocketry, I'll try to post a MM picture tonite. Happy Building!
Okay, sorry I wasn't able to post a photo last nite. I haven't done much work today either. True to my screen name I was replacing a radiator today. Anyways, I wanted some stronger centering rings for the inevitable composite engines going in this Saturn V. I epoxyed the thrust ring in, but I didn't want to wait on custom centering rings. I just covered the surfaces of the stock rings with wood glue. I don't know (and didn't ask) if anyone has done this before. Just an experiment I thought I'd try. It seems to have made a "seat-of-your-pants" difference, but I think the CR's will hold up to the kick of an F21. If anyone has tried this with good or bad results, please let me know, but I may go on ahead with this one like it is. :D Here's a photo of the centering rings.
Don't know about wood glue for reinforcement but a friend of mine covered some Estes cr's with Elmers Probond Polyurethene glue and they were rock solid. Worked perfectly.
The next time I'm out at Lowe's or Rocket Depot, I'll pickup a bottle or Elmer's Probond. I've seen it before, unfortunately, how do you say, Elmer's sort of has a stigma in my own mind. I always think of Non-Tox School glue. Looks like Elmer's makes stuff for the big boys too. Back to the wood glue, (it's Titebond, btw) it makes some difference, just not as much as I was hoping it would. You live, you learn......... I'll make another! ;) Old school 4 x 18mm cluster.
I have had a Sat V for about a year now, and have decided that I MUST build it come springtime, after I clear away the its-too-cold-to-paint backlog. I will be following this thread with interest. I have already decided on the Moldion Oldies fins and an ESTES 'E' length mount for F21s. Aerotech will be shipping 750 of them in a week or so, stock up!!
Originally posted by TheRadiator
If anyone has tried this with good or bad results, please let me know, but I may go on ahead with this one like it is. :D Here's a photo of the centering rings.

I usually use epoxy when I'm building for composite 24mm's, but I think you should be fine. The rings are fairly strong to begin with, so anything will help. Just make sure the bond of the motor mount to the body tube is strong - once again, I use epoxy for this part.

Yes indeed, I will be using epoxy for the fore and aft ring. I used wood glue for the middle ring for sake of making it easy to insert the assembly into the main body tube. I've got a little 30 minute epoxy for the fore and aft rings. No worries there now! I'll try to get photos of the mount in the main BT in the next day or so. Unfortunately, my build speed is pretty slow with all the other things going on right now. Anyways, I need more epoxy as well, so I'll put that on my Lowe's/Rocket Depot list.
Alright fellas, need more input...

I've got the MMT cut to length and dry fit with the centering rings, a spare Aerotech engine hook, and phenolic thrust ring. There's also a medium eye bolt mounted in the forward ring for the chute (30" main). I've also assembled the engine bells.

Nothing has been epoxied in place yet, nor have I drilled for an internal lug. I may not do that - with a 29mm tube plus engine bells, things are getting crowded in there.

Now, here's the problem. Exactly how far should the aft ring be from the end of the body tube if it's also going to be where I mount the engine bells? Don't I have to cut away some of the aft body tube once the corrugated wraps are glued in place? It's a little hard to visualize it ahead of time.

If I can't get my brain around this problem I may just leave the motor mount in dry-fit with no epoxy until the wraps are done and everything's cut away. Make sense?
Sorry fellas, got sidetracked with my simultaneous project. But I've epoxyed the motor mount into the main body tube. So far so good, but I haven't even gotten to the fun stuff yet! Here's a photo of the business end as of now. Oh yeah, this project is gonna take awhile! ;)
Thanks for the link! However, I have been checking that FAQ before I start a new step! I planned on using E30's and D12's most of the time. Which is why I decided to stay with a 24mm motor mount.
I want to get a Saturn V, and put a 29mm motor mount in it :). Stick a G40 in it. Then after somebody does their Saturn V on a D12.... I will put it on the pad.... :D
I still have a Saturn V NIB from one of the Hobby Lobby sales, but I'm keeping it for my collection. I did want to build one , however HL doesn't stock em anymore.

What swung me on putting in the 29mm mount was picking up a 40/120 RMS casing. I can put it up on F20s or G35s and still fly it on E16s in small fields if it's kept light enough (we'll see about that - I tend to build heavy).

If we ever get a break on the weather, this Saturn will premier at the Tripoli Mid-Ohio launch in late March or early April.

I've taken a couple of good construction pics but they're on old fashioned 35mm film. Soon as I get it on photo disc they'll be posted. Should've treated myself to a digital camera for my birthday instead of all that rocket stuff...:p
Chilly - I am just starting my Estes Saturn V and I want to do as you are doing with the engine mount. Move it back and use the 4 outside engine bells. Where did you wind up mounting the MMT?
Have you figured out how much weight you will be adding to the nose for stability?
I am thinking I need to bring the MMT down to where it extends out the bottom the same length as the engine bells and add 2-3ozs of nose weight (just a guess right now).

Also, has anyone done a cluster on this model where you have a 24mm in the center and maybe 3 - 18mm around the outside of the 24mm? In a scenario like this, would you extend the 18mm MMTs up into the chute bay for added ejection or would you use plugged motors in the 18mm MMTs?

If the 18mm MMTs WERE extended into the chute bay AND I decided to just launch with a single motor in the 24mm MMT, how would you plug the 18mm mmts so the ejection gasses wouldn't blow back down through them?
I haven't quite figured out where to position the MMT. The middle and forward cr's are epoxied in place and the aft ring will be last. Right now it's all dry-fit in the body tube for support while the wraps are glued in place. Once they're done and the fin shrouds are attached, I'll just glue in the MMT wherever it makes the most sense. But I figure the aft ring should be recessed about 3/8" from the rear end.

The engine bells are glued to the kit card stock and will be reinforced with a kit centering ring, hollowed out for 29mm. Then I'll just CA the whole thing to the aft ring - reason being is if something happens to the bells it'll be a lot easier to remove them than if they're glued to a plywood cr.

You'll want to make sure the motor tube is cut longer than the supplied 24mm tube. Mine is cut to 20 3/4". I was worried about the "scale" appearance at first but it ends up looking really cool nestled between those 4 bells. I don't get too hung up on that sort of thing, although it is a lot of fun to strive for accuracy.
Also figure on having it extend a little bit past the engine bells, otherwise you'll probably melt them in flight.

Just a guess, but I figure on about 5 oz. of nose weight for now. I want it to be a little more on the over-stable side than the stock kit. I'm also building the 3rd stage heavy with basswood gussets under the reduction wraps. They add strength and weight in the right places.

Anyone have a good CP location on the Saturn V? Or a Rocksim file for that matter? The file I have won't load but I'm just running the demo version.
Thanks for the info Chilly - that's about where I'm at - put the wraps on last night and just shoved the centering rings into the BT to keep it round for the wraps.

I just can't decide how I want to power this thing but I am leaning toward the 24mm single mount with the intent of using E15s. If I go this way I can use the engine bells for a more scale look on the pad.

Yet the temptation to do a cluster on this model is strong.

decisions, decisions....
I wouldn't recommend. Aerotech may not bring back the E15's, and the F21's are usually harder to find than F20's. And as I mentioned earlier, a 29mm mount will allow you to use an E16 if you have an RMS.
I wouldn't recommend it. Aerotech may not bring back the E15's, and the F21's are usually harder to find than F20's. And as I mentioned earlier, a 29mm mount will allow you to use an E16 if you have an RMS.