Estes Cosmos Mariner

[Donaldsrockets]

Sorry to hear this but I can't really say I'm too surprised given the very bad reputation this kit has.

I think this kit actually beats the Dude balloon rocket for being the biggest piece of junk that Estes has ever released.

Too bad though, the finished model looked great.

 

[DAllen]

Wow...blew out the nose? That's not what I expected. I wonder if that might be more of an issue with the motor rather than the CM. Then again, if the gases are confined too much because of the effort it takes to push out the engine pod with all that weight on it maybe that makes sense.

Pictures and/or video possibly?

-Dave

 

[Donaldsrockets]

Wow...blew out the nose? That's not what I expected. I wonder if that might be more of an issue with the motor rather than the CM. Then again, if the gases are confined too much because of the effort it takes to push out the engine pod with all that weight on it maybe that makes sense.

Pictures and/or video possibly?

-Dave

Yes that makes perfect sense. While I never actually had the nose blow out like John did, the ejection pod would always eject with a very loud and distinctive BOOM!!!

I also stripped a few Estes chutes on the pod from the force too. One time it kinked the pod tube on impact but I fixed that with a few wraps of duct tape.

Part of that problem could also be from the "firecracker" ejection charges that a lot of the newer Estes motors seem to have, especially the 13mm.

For apps like this I wish the ejection BP was separate from the motors. That way, you could add the amount you need for any particular rocket.

 

[JAL3]

I ill get pics and vids up but will not be able to get to it until tomorrow night at least.

The pod popped on the ground. It stripped the chute. It blew out the nose. It flew about 70 yards back to the flight line and almost beaned Stu who was prepping his Vega. We were talking about the "flight" when we heard the pop and saw the missile come sailing back towards us.

BTW, the guy who won the parachute duration contest chose a Dude as his prize!!!!!!!????

 

[CharlaineC]

dagnabbit so sorry for the loss with all the work you put in to her and she didn't even leave the groung. poo

 

[georgegassaway]

The pod popped on the ground.

Uh-oh, then it sounds like the flight went terribly bad for the model to be on the ground when the ejection went off.

Well, if it was on the ground when the ejection fired, then I have one theory on why the bulkhead at the front end of the tube would blow out. The pod has a lot of mass, and the glider has a lot of mass. When the ejection goes off in mid-air, the pod not only gets kicked backwards, but the glider also gets kicked FORWARDS. But if it was already on the ground, the glider was not going to slide forward too easily.

Indeed you have not given much info yet, so possibly it did “stick the landing”? Perhaps with the nose into the ground, and the aft end angled “up” a bit. Indeed, for the pod to travel as far thru the air as you describe, that sounds like a “mortar” firing off at a shallow angle, not a model laying parallel to the ground.

Anyway, if the glider was “stuck” and unable to get kicked forward at ejection, then the pressure of the ejection charge kicking the pod out the back may have built up a lot more than when the glider can get kicked forward. And that higher than normal pressure may have been enough to blow out the front end of the tube (or bulkhead - I have never built one), even though the pod had achieved enough backward momentum to travel as far as you described.

Or, if that was not it, another cause could be if the pod was not a reasonable slide-fit, or if when it started to eject backwards the chute around the pod might have jammed.

The nose section being blown out reminds me of what happened to my first R/C X-1 model in 1984 or so, on its one and only flight. I won’t go into all the details, except to say the engine was supposed to eject and yank about 4 ounces of noseweight out with it. Effectively the ejection charge overpressured the engine compartment, causing the front end of it to blow out, which in turn caused the entire rolled balsa rear fuselage to blow apart.

- George Gassaway

 

[thunderdog]

hi,
You know mine went in under power 10 weeks or longer ago emailed estes got a answer and never a replacement kit i got 6 emails from them oh next week, in a day or two but NEVER a relacement starting to get upset any one have a phone# for estes that someone answeres?:bangbang:

 

[JAL3]

Uh-oh, then it sounds like the flight went terribly bad for the model to be on the ground when the ejection went off.

Well, if it was on the ground when the ejection fired, then I have one theory on why the bulkhead at the front end of the tube would blow out. The pod has a lot of mass, and the glider has a lot of mass. When the ejection goes off in mid-air, the pod not only gets kicked backwards, but the glider also gets kicked FORWARDS. But if it was already on the ground, the glider was not going to slide forward too easily.

Indeed you have not given much info yet, so possibly it did “stick the landing”? Perhaps with the nose into the ground, and the aft end angled “up” a bit. Indeed, for the pod to travel as far thru the air as you describe, that sounds like a “mortar” firing off at a shallow angle, not a model laying parallel to the ground.

Anyway, if the glider was “stuck” and unable to get kicked forward at ejection, then the pressure of the ejection charge kicking the pod out the back may have built up a lot more than when the glider can get kicked forward. And that higher than normal pressure may have been enough to blow out the front end of the tube (or bulkhead - I have never built one), even though the pod had achieved enough backward momentum to travel as far as you described.

Or, if that was not it, another cause could be if the pod was not a reasonable slide-fit, or if when it started to eject backwards the chute around the pod might have jammed.

The nose section being blown out reminds me of what happened to my first R/C X-1 model in 1984 or so, on its one and only flight. I won’t go into all the details, except to say the engine was supposed to eject and yank about 4 ounces of noseweight out with it. Effectively the ejection charge overpressured the engine compartment, causing the front end of it to blow out, which in turn caused the entire rolled balsa rear fuselage to blow apart.

- George Gassaway

Its 845 PM and I just got home after leaving at 630 this morning. I am going to try to get around to this tonight but no promises.

George is pretty close in his analysis. The main difference I would note would be to liken it to a piece of siege artillery like a flank howitzer rather than a mortar. It was a pretty flat trajectory.

 

[JAL3]

After so long building, my Cosmos Mariner finally got a chance to fly and prove its detractors wrong. I loaded it with a D12-3 and inserted the engine pod. It was very loose and I added a few wraps of cellophane tape to hold it in and it just barely kept it from falling out the back end. It was put on the rod and I have to admit, it didn't look too bad.

 

[JAL3]

It looked even better at ignition. My normally pessimistic self made the mistake of feeling a twinge of optimism.

 

[JAL3]

Soon after leaving the rod, it arced over and proceeded horizontally for a while, slowly losing altitude. It hit the ground a little over 70 yards away.

 

[JAL3]

I was discussing the poor performance of the rocket with some of the guys at the launch when we all heard the ejection charge go off. It had already been on the ground for a few seconds. Then someone called, "Look out!" and I saw a tube flying back towards us with a very flat trajectory. It missed me by about 10 feet and tried to impale Stu Young's Upscale Vega. It missed.

 

[JAL3]

The rocket was found on its side, tail slightly up and with no damage to the wings or fins. The forward end, though, was a mess. The charge had blown out the front and stripped the weights off.

I gave the carcass away to a youngster who thought it was neat.

 

[JAL3]

I have some video that shows a little more including how the rocket was found but it will take me a while to get it edited.

 

[DAllen]

Wow. Just. Wow.

I think you have discovered a new way for this rocket to fail.

Did it spin on the way up? It's supposed to do that as it leaves the rod. Maybe you had to put too much nose weight in the glider to get it to glide correctly. That's the thing I hated about the CM; the D12 was just BARELY powerful enough to get it off the ground but putting a larger motor in it just seemed like asking for disaster.

-Dave

 

[JAL3]

Wow. Just. Wow.

I think you have discovered a new way for this rocket to fail.

Did it spin on the way up? It's supposed to do that as it leaves the rod. Maybe you had to put too much nose weight in the glider to get it to glide correctly. That's the thing I hated about the CM; the D12 was just BARELY powerful enough to get it off the ground but putting a larger motor in it just seemed like asking for disaster.

-Dave

Spin is a pretty active verb. I would say it gently rolled about the longitudinal axis...maybe once for the whole flight. I can check the video when I get to it.

 

[georgegassaway]

Seeing the pics, well, it seems like a lot of damage to the nose was from impacting the ground. All that dirt jammed into the cracks and breaks that opened up. To which the front bulkhead blowing out was adding insult to injury. Also, it is possible that the crash may have damaged the tube, bulkhead, or damaged the glue joint holding the bulkhead to the front of the tube.

If you were going to trash it, then OK, best to give it away. But after all this, I wish you’d kept it to try to do a fix to see if it would fly. I do not mean spend lots of time to make it look really pretty again type of fix, I mean “Git R’ Done” type of fix, cosmetics be “darned”, to see if the boost issue could be solved and get it into a glide (then if successful, make it pretty later).

Although, this kit does tend to fall into the category of “Fernando” kits. As in the Billy Crystal character he did on SNL (“You look Mahvelous”). To do a twist on his other motto: “It’s better to LOOK good than to FLY good”.

Or to summon another motto, this time from the movie Wargames: “The only winning move is not to play”. So maybe the second-best winning move was to give it away as you did.

- George

 

[Fred22]

Sorry John I had hoped for better for you
Cheers
fred

 

[JAL3]

I finally have the video. It does appear that the CM did some barrel rolls on its way to oblivion.

The vid is here: https://www.flickr.com/photos/23694991@N03/3957262511/

 

[AKPilot]

So, with John taking probably the most precautions of anyone I know in getting one of these to fly, and in me having one still in the package unbuilt, what's the lesson learned here in getting one to fly succesfully?

Outside of the obvious of not doing it.

 

[DAllen]

That looks very familiar to me. That's exactly what mine did except not so close to the ground. Mine ejected the pod and the glider did a hard half turn dive and smashed up the nose sort of like yours. The more I look at this video I am wondering if this is a serious case of rod whip. AK...I am wondering if there is some way to get this on a rail. I just don't think the D12 gives enough punch off the pad for a 3' long 3/16" rod. You really need about 6' of much bigger rod or rail. Maybe 1/4" lugs?

I know I've been sort of teasing you a bit John throughout this thread but I was hoping you'd get at least one more flight out of it than that.

:bangpan:

Estes was willing to recall the X-15 but not the CM?

:confused2:


-Dave

 

[hcmbanjo]

Quote from Jal3
"It does appear that the CM did some barrel rolls on its way to oblivion."

Hmmmm . . .
"Did some barrel rolls on its way to oblivion."

That's a Country song just waiting to be written!

I shouldn't make light of this. Sorry to see such a tough landing after a great build thread. We've all been there, maybe too many times.

 

[El Cheapo]

That stinks, John...but in my best overall wearin', Texas-Minister accent, "this is the Cosmos Mariner. It's got a bad reputation, so, HEADS UP!!!!!!" That was just funny :roll:

 

[aerospike]

To all of you worrying about being killed by a Cosmos Mariner, send me your unbuilt kits and I'll relieve you of your hazard.

 

[JAL3]

So, with John taking probably the most precautions of anyone I know in getting one of these to fly, and in me having one still in the package unbuilt, what's the lesson learned here in getting one to fly succesfully?

Outside of the obvious of not doing it.

I suggest an airmail stamp

 

[JAL3]

That looks very familiar to me. That's exactly what mine did except not so close to the ground. Mine ejected the pod and the glider did a hard half turn dive and smashed up the nose sort of like yours. The more I look at this video I am wondering if this is a serious case of rod whip. AK...I am wondering if there is some way to get this on a rail. I just don't think the D12 gives enough punch off the pad for a 3' long 3/16" rod. You really need about 6' of much bigger rod or rail. Maybe 1/4" lugs?

I know I've been sort of teasing you a bit John throughout this thread but I was hoping you'd get at least one more flight out of it than that.

:bangpan:

Estes was willing to recall the X-15 but not the CM?

:confused2:


-Dave

I thought about the 6' rod we don't have...and decided to just light the candle.

I was hoping to get more out of it but I'm glad to have finally gotten it out of my system.

 

[JAL3]

Quote from Jal3
"It does appear that the CM did some barrel rolls on its way to oblivion."

Hmmmm . . .
"Did some barrel rolls on its way to oblivion."

That's a Country song just waiting to be written!

I shouldn't make light of this. Sorry to see such a tough landing after a great build thread. We've all been there, maybe too many times.

Doubtless I'll be there again at some point.

I can't say I enjoyed the build or the flight...but I am glad to have done both.

 

[JAL3]

That stinks, John...but in my best overall wearin', Texas-Minister accent, "this is the Cosmos Mariner. It's got a bad reputation, so, HEADS UP!!!!!!" That was just funny :roll:

You should hear it when I'm really dressed up.

I never used to wear overalls. I had some surgery back in 2005 that cut me all around the waste and now belts irritate the scars so I wear suspenders or overalls. I feel like Junior Samples.

 

[El Cheapo]

Exactly who I was thinking of. That's even funnier.

 

[Fred22]

John you deserved a better fate. What other gliders have you built or flown?
Cheers
fred