Estes 1/200 Scale RTF Saturn V

kuririn said:

Nice work. I was wondering if anyone has considered using the motor retainer to lock down the fin unit as in the stock kit? You would have to print up a new unit for that since the Estes 24mm retainer does not extend past the threads enough. That would combine the functions of the screw down plate and bayonet retainer into one.

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I thought of that but did not have time right now have other projects too, I spent 6 hours designing that thing, tinkercad is kind of a pain in the ass... also want to add the round things sticking out of the bottom of the stock plate so it will fit on the display stand...look for version 2 later...it will be a few weeks...

kuririn said:

I just stuck mine in.

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That's interesting. Based on the tiny nozzle, I don't see how that's even possible. I'll have to experiment.

I will say the motors seem really nice otherwise, and afadeev's 1:200 Saturn V flew great on the C14.

neil_w said:

I will say the motors seem really nice otherwise, and afadeev's 1:200 Saturn V flew great on the C14.

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Good news as I haven't gotten to fly mine yet. Too windy the past few weekends. And I'm getting "the itch".
BTW masking tape should also work for Cs and Ds, just leave an opening. AT used to supply tiny rubber bands with their composites that you would loop around the nozzle to hold in the igniter. Don't know if they still do that. The issue with the initial run of QJets was that masking tape was recommended to secure the igniter but the lower impulse As did not have enough impulse to blow out the igniters and they would take the igniter and clips up with the rocket. That's why AT came up with the heat shrink tube solution. Laters.

neil_w said:

That's interesting. Based on the tiny nozzle, I don't see how that's even possible. I'll have to experiment.

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Neil, you piqued my curiosity. The pic I had was a QJet D motor. I looked at the C motor and the inside bore of the nozzle is markedly smaller. So if the tube doesn't fit maybe masking tape? Or do a Z bend on the igniter and use a small rubber band like the bigger AT motors? Cheers.

neil_w said:

I flew my first Questjets on Saturday, and I could not for the life of me to get the red tubing in there like that, way too tight. It just would not go in. I managed to get the first one just in enough to hold, but for the second flight I gave up (it kept falling out at the pad) and borrowed a matchstick from afadeev.

Is there some mysterious trick to getting the red tubing all the way in there so it'll hold?

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Hmm..odd! I used both C and D motors the other day and had no problems with the initiator “holder” fitting into the nozzle. I did have a nozzle blow out and crash my MPC Enterprise (MESS filed, CATOd motor headed back to Quest) but no ignition problems at all.

kuririn said:

Neil, you piqued my curiosity. The pic I had was a QJet D motor. I looked at the C motor and the inside bore of the nozzle is markedly smaller.

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Scott_650 said:

Hmm..odd! I used both C and D motors the other day and had no problems with the initiator “holder” fitting into the nozzle.

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Hmm.........

Left: C12
Right: D16

We had 2 flights at a demo launch today one was rather slow of the pad but flew okay, the 2nd left the pad made a hard turn, looped back around and hit the ground. Nothing not a single thing was different about how the rocket was prepped and flown. It's obvious this rocket is marginally powered using the C6. What's disconcerting, approaching the anniversary next month, is that apparently Estes thinks all it well.

On the heat shrink to hold in Q-Jet initiators: The nozzle size seems to vary by impulse. It's very difficult to get the tubing in on a B4, snug on a C12 and pretty easy on a D16 in my experience. I'd expect the A3s to be harder still (or need smaller heat shrink tubing to hold the initiator in).

Of course A3s and B4s are not suitable for the 1/200 Saturn V really since there aren't any A3-1s or B4-2s in the Q-Jet line.

jahall4 said:

We had 2 flights at a demo launch today one was rather slow of the pad but flew okay, the 2nd left the pad made a hard turn, looped back around and hit the ground. Nothing not a single thing was different about how the rocket was prepped and flown. It's obvious this rocket is marginally powered using the C6. What's disconcerting, approaching the anniversary next month, is that apparently Estes thinks all it well.

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Max Lift Wt. for C6-3 according to Estes Engine Chart as listed on EstesRockets.com
113 grams.
Quote FROM the chart
“Do not fly a rocket/engine combination whose lift-off weight exceeds the recommended maximum lift-off weight.”
https://estesrockets.com/wp-content/uploads/Educator/Estes_Engine_Chart.pdf

Estimated weight of Estes Saturn V again from EstesRockets.com
“5 oz. (141.7 g).”

“Recommended Engines.........C6-3” https://estesrockets.com/product/002160-saturn-v-1200th-scale-ready-to-fly/

??????????????

BABAR said:

Max Lift Wt. for C6-3 according to Estes Engine Chart as listed on EstesRockets.com
113 grams.
Quote FROM the chart
“Do not fly a rocket/engine combination whose lift-off weight exceeds the recommended maximum lift-off weight.”
https://estesrockets.com/wp-content/uploads/Educator/Estes_Engine_Chart.pdf

Estimated weight of Estes Saturn V again from EstesRockets.com
“5 oz. (141.7 g).”

“Recommended Engines.........C6-3” https://estesrockets.com/product/002160-saturn-v-1200th-scale-ready-to-fly/

??????????????

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Yep, not surprised in the least. Thanks for the links. I had already told Estes that this rocket won't be allowed to fly using the C6-3 if I'm serving as RSO. Now there is no room for argument. Turns out the rocket weighs even more, the Est. 141g is closer to a "dry" weight. "Wet" it weighs in excess of 160 w/o wadding and igniniter.
View attachment 385704

Has Estes ever recalled a rocket?

BABAR said:

Has Estes ever recalled a rocket?

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No idea but given the reason they released it, for the anniversary I doubt they will do anything about it. They probably have many 1000s sitting out there with their vendors who will be harmed financially with only a month to go. I expect there will be some close calls with the starter sets and flyers being only 15 ft away.

BABAR said:

Has Estes ever recalled a rocket?

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I believe they recalled an early X-15 model. IIRC it was notoriously unstable and someone got injured.

kuririn said:

I believe they recalled an early X-15 model. IIRC it was notoriously unstable and someone got injured.

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Yep, remember reading about that now.

Correction: The original Quest X-15 was notoriously unstable. The Estes/Cox X-15 had a problem with the retainer ring and it would come off, resulting in a non deployment of the recovery package. Someone's arm was injured requiring surgery.

Instead of turing flyers away we are going to maintain a small stash of motors that would essentially adhere to Estes's own guidelines. Of course Estes doesn't have an 18mm motor that works dependably so well have to turn to a another Manf. I have seen Quest mentioned here.

What specific motor(s) is everyone determining works best in a unmodified Sat' V?

BABAR said:

Has Estes ever recalled a rocket?

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I don't see any need to recall 1/200 SatV.
However, I would not advise flying it on C6-3 motors, as they are way too marginal for this rocket.

jahall4 said:

Instead of turing flyers away we are going to maintain a small stash of motors that would essentially adhere to Estes's own guidelines. Of course Estes doesn't have an 18mm motor that works dependably so well have to turn to a another Manf. I have seen Quest mentioned here.

What specific motor(s) is everyone determining works best in a unmodified Sat' V?

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Quest (C12 and D16) and Aertoech (D13 and D24) motors are the only ones I will be using for this model from here on out.

YMMV,
a

afadeev said:

I don't see any need to recall 1/200 SatV.
However, I would not advise flying it on C6-3 motors, as they are way too marginal for this rocket.



Quest (C12 and D16) and Aertoech (D13 and D24) motors are the only ones I will be using for this model from here on out.

YMMV,
a

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Good point. Is it “the right thing to do” for Estes to step up and acknowledge the problem and take action to relabel all current stock and notify all who bought the rockets on web site of , how shall we put it, “better” choices for flying other than the C6-3?

If I was a kid new to rocketry and got this beautiful rocket and it did skywriting and crashed and broke a fin on first flight, I would be really bummed.

afadeev said:

I don't see any need to recall 1/200 SatV.

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But remember the box says use a C6-3 and starter kit comes with C6-3. How can you sell someone motors for a rocket then say use something else that you don't even sell.

jahall4 said:

Instead of turing flyers away we are going to maintain a small stash of motors that would essentially adhere to Estes's own guidelines. Of course Estes doesn't have an 18mm motor that works dependably so well have to turn to a another Manf. I have seen Quest mentioned here.

What specific motor(s) is everyone determining works best in a unmodified Sat' V?

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From posts about flights and my own experience if you are going to have motors available for flyers, I would get a bulk pack of quest C12-4. Just make sure they work at twisting the motor so it pops all the way in and they can lock down the fin unit properly.

BABAR said:

If I was a kid new to rocketry and got this beautiful rocket and it did skywriting and crashed and broke a fin on first flight, I would be really bummed.

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Interestingly I don't think it will happen on the first flight.

Our working theory is that that the heat from the ejection charge from the first flight starts to deform the forward centering ring which doubles as a forward motor tube. The deformation is obvious after a couple of flights if you remove the aft centering ring that doubles as an aft motor tube and retainer. This deformation results in the next motor being ever so slightly misaligned. While we all have seen rockets, even HP ones, built with slightly misaligned motor tubes or failed nozzles fly just fine, this rocket's launch velocity, from being under powered, means the fins, even though they are large, can't overcome the off center thrust vector. Essentially the safety margin is just too small. Higher thrust motors and/or longer rods should mitigate this problem.

If someone earlier in this thread has noted the deformation my apologies for not affording credit where due

jahall4 said:

The deformation is obvious after a couple of flights if you remove the aft centering ring that doubles as an aft motor tube and retainer.

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Pictures, please.

kuririn said:

Pictures, please.

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Well see, right now I'm adverse to getting sued Currently all this is in the realm of observation, theory, and opinion. I have made some calls and done what I think is required of me to avoid any potential personal liability for recommending the kit to a room full of children and their parents.

jahall4 said:

Our working theory is that that the heat from the ejection charge from the first flight starts to deform the forward centering ring which doubles as a forward motor tube. The deformation is obvious after a couple of flights if you remove the aft centering ring that doubles as an aft motor tube and retainer.

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I agree - pictures, please. I have three flights on my 1/200 S-V (as readers of this thread already know), one on a C6-3, one on a C12-4 and one on a D12-4. The forward ring on mine after those three flights is pictured in a post further up in this thread. It's not deformed.

I still think the key is making sure the motor is ALL THE WAY IN that upper ring to begin with. Then it's straight and the fins are retained tightly. And no ejection charge gases would be coming into contact with the part of that ring that supports the upper end of the motor—the only heat would be coming through the motor case itself.

I can only speak from my own experience. At a local scout function I flew two Saturn V's a total of seven flights on C6-3's, all flew straight and true with no recovery issues.

BEC said:

And no ejection charge gases would be coming into contact with the part of that ring that supports the upper end of the motor—the only heat would be coming through the motor case itself.

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Sure it would from the forward side of the ring as the heated air fills the stuffer tube. No way to avoid it. IMO the use of plastic in this way at that location is part of the problem.

I don’t think there is a problem....other than liftoff mass is a bit much for C6 on a three-foot rod and people being unwilling to exert enough force on a motor (twisting does help) to get it all the way in

Here are four more pictures of the insides of my model with the three flights on it. The first shows the upper ring from the motor side. No “distortion”. The second shows the upper ring from inside the model, with a C6-3 installed. You can see the ID of the motor’s case is less than that of the plastic part. The next two show a Q-Jet installed - one straight down and one at as much of an angle as I could get to show that the top of the ejection charge container in a Q-Jet is above the bottom of the inside of the model altogether. This, I suppose, could be why there has been a little less “cooking” of the plastic than had I flown three flights on a C6.

The Estes plastic screw-on motor retainers and the red size adapters (13-18mm, 18-24mm and 24-29mm) also survive multiple uses without damage. The 13-18mm one in particular has to deal with ejection charges for an inch of its overall length. It does so just fine.

I have had one plastic motor mount issue with a different model (an RTF called Sizzler) when I put an Aerotech D10 in it. That one needed some rework post-flight to be usable again. There the issue was the hot phenolic case heat-soaking into parts of the motor mount. This is why I’d love to see the inside of one of these Saturn Vs where someone has flown it with a D10 or the 18mm RMS case to see how it fared. But the Sizzler used a different plastic I am fairly certain.

BEC said:

I don’t think there is a problem....and people being unwilling to exert enough force on a motor (twisting does help) to get it all the way in...

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There is a problem if the motor can be pushed home and the retention cap installed with no play remaining between the fin can, which is exactly what we observed. Further it's unreasonable to expect anyone much less the lay consumer to inspect the forward end of the motor as it engages the forward centering ring using a flashlight as you are doing in your pictures. Bottom line is that any possibility of installing the motor at a slight angle and it not being retained at the fore end (if that is going to be the Estes argument for why it does not fly straight) could have been made impossible in the design of this rocket if they had simply used a typical motor tube and thrust ring like they do in so many of their other rockets.

BTW... it's not that anyone would be "unwilling" it is that there would be no expectation of having to "exert force" just to get the motor to slide into its tube. Obvious exception being friction fit mounts.