Full scale HPR V2 project

https://makezine.com/2015/03/09/biggest-amateur-rocket-ever-built/

https://www.worldrecordrocket.com/index.php/construction

:y::eyepop:
Wow, that's amazing!

I must admit that I don't actually care much for this rocket. The thing isn't proportional at all with regards to size, mass and thrust. It's 617 pounds as compared to the REAL V-2 which was 27,000+ pounds. Also, these guys are using a single CTI O25000 which has a thrust duration of 1.2 seconds. That's their burn time. That's it. I haven't tried to sim anything this big but my gut says it'll be lucky to hit 4000 feet and my money would be on closer to 3000. But, more importantly, I don't think it's be very exciting to watch unless it has a catastrophic failure (we all love to watch those).

No, I don't expect it to be as massive as the real thing or have the same thrust, but it should at least be a bit more proportional. Burl Finkelstein, for instance, built a 16+ foot tall, 2/5ths scale V2 that weighed, when the motors were loaded, just over 600 pounds. It also had about 50% more total impulse (thrust over time) than this behemoth. Another example: Steve Eve's 36 foot tall Saturn V was about 1300 pounds, as I recall, and had 181,000 total Newtons of impulse versus 30,000 for this rocket.

These guys are going all-out to break the size record, which is a great goal and I'll be happy for them if they get it....but this almost seems like cheating. To me, even if this thing flies and recovers as planned, it's more of a caricature of a rocket than an actual rocket. It reminds me of that old Estes mylar inflatable rocket called "The Dude" that was 7 feet long, 4 or 5 inches or so in diameter, and powered by a tiny D12-3. Sorry for all the negativity on what I'm sure is a massive amount of work and money, but I just can't get 100% behind it.

Hmmm... Maybe I should build a 50 foot tall inflatable rocket powered by a K700 so I can have the record all to myself. I can see it now: "Featured Flight at LDRS: Glenn Harper's Mega-Dude Extreme!" :wink:

I also think the motor selection will produce a less impressive flight than what could be achieved, but I am really impressed with the construction. If they're having fun building it and have a successful flight, I'll be cheering right with them.

I disagree, big low and slow is just as good to me...I appreciate large and light airframes instead of using hardware store materials....and have been experimenting with foam construction on 7.5" diameter rockets lately...Why is it cheating to smartly design a light airframe and use an appropriate motor?



Frank

I think low and slow is great. You can get photos easily.

Old news. I also question motor choice.

I believe they are predicting 700 ft altitude.

There are many paths to rocketry Zen. As long as it is safe and it makes them happy, great. It has to be safe, the minimum distance for an O has to be more than the worse case potential arc of that thing. I am amazed they could make a flight worthy airframe that size at that weight. Impressive engineering in my book.

burkefj said:

I disagree, big low and slow is just as good to me...I appreciate large and light airframes instead of using hardware store materials....and have been experimenting with foam construction on 7.5" diameter rockets lately...Why is it cheating to smartly design a light airframe and use an appropriate motor?

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It's not cheating to smartly design something to be light and strong. That wasn't the point. The point is that this rocket is completely built from the ground up to just barely work. It's a gimmick - a well designed gimmick that took a lot of very smart and dedicated people to make, to be sure - but it's still a gimmick. The performance envelope is minuscule and there's only one commercial motor in the world that can even get it off the ground and clear it's own launch mechanism with enough velocity to be stable (we hope).

Why wouldn't they make it so it could hold 2 or even 3 O5000s which would get it to an altitude that gives at least a tiny margin for error? Because the structure isn't strong enough. In a prior life I was a student of game theory and, in gaming, there was a phrase that came up a lot called "min-maxing" or, in other words, mathematically squeezing the most benefit out of something for the least cost. In my opinion (and, truly, it's just an opinion - there are different ones just as valid as mine) this rocket is a min-max effort. It's the tallest but with the absolute minimum mass. It will fly, but only at a minimal altitude. It's as one-dimensional as it gets - it's tall but in every way else it under-performs. Again, the term "under-perform" is my own and just an opinion, but am I alone to want a record holding rocket to not just perform, but perform WELL and with some pinache'?

But I can't shake it. New questions pop into my head every time I read about this rocket. Just now I had these thoughts: 1) if it deploys it's chutes at the predicted 700 foot apogee, how far would the rocket fall before they fully inflate? Is 700 feet enough for something this big? Seems this is a very close margin to me. 2) The surface area-to-mass ratio: How strong a breeze do you think this thing would be stable enough to fly in? With so much surface area and so little mass, I'd be terrified to launch it in anything other than perfectly still wind conditions.

I read an article recently that seems to be a good parallel where this 6'11", 500 pound guy wanted to play in the NFL. He currently plays defense for a minor league football team but he's so big and heavy and out of shape, that all he does is create a small wall that the opposing team can't run through and he blocks the vision of one or two offensive linemen so they can't see what the linebackers are doing on every down. Yeah, an NFL team could bring him and and let him play for them and he would get the record for being the "largest man ever to play in the NFL", but he wouldn't be playing well and he'd still be just a gimmick.

cwbullet said:

I think low and slow is great. You can get photos easily.

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I think low and slow is good, too. I fly a Minie-Magg on H motors all the time and even an occasional G125. But even with a G125, it's going to get much more than 15 times it's own length in altitude and I know that it CAN fly well on a much bigger motor.

Cl(VII) said:

There are many paths to rocketry Zen. As long as it is safe and it makes them happy, great. It has to be safe, the minimum distance for an O has to be more than the worse case potential arc of that thing. I am amazed they could make a flight worthy airframe that size at that weight. Impressive engineering in my book.

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With regards to rocketry Zen, I agree with you there. As to this rocket being flight worthy, that remains to be seen. *If* it flies well and succeeds, then we can agree on this point, too.

Scaling up a loc V-2 to 65" diameter an 600 pound override and O25000 gives me around 850 feet....low and slow.........at that size....As for thrust to weight that's about 8:1....

I am duly impressed by these "Men in the Arena" and looking forward to seeing it fly.

Apogee at 700 feet isn't going to look like much when the nearest people can be to witness the launch is 1500 feet. But, it still should be quite impressive.

I've been following the V-2 project with considerable interest because a group of us were planning a large-scale project that would have required the rocket to be relatively light-weight. We never settled on a good method of constructing the rocket and moved on to other projects. But, seeing how the V-2 was built might help us if we decide to restart the effort. The team building it has done an incredible job. It looks great and ... it's really big!

-- Roger

Although it is pretty cool, i still think it pales in comparison to the current record holder Steve Eves and his Saturn V, at 1:10 scale it was 38ft tall and weighed over 1600lbs and took 1 "P" and 8 "N" motors to a little over 4400ft.

Hope they've thought through 'chute deployment as well as (it appears) the construction. They have to know that 700 ft. is leaving little margin for error. Looking forward to the video.

This is a truly incredible project. That's a massive undertaking. That said, and knowing full well I have absolutely 0 experience with large projects, I feel like 700 feet is pretty low for the rocket to separate, deploy a chute, unfurl the chute, open the chute, and have it slow the rocket down. I'll be eager to see how this turns out one way or another!

Nate

Look up BASE jumping deployment altitudes and techniques for deployment. I found it to be very educational.

Good Luck,

Duane

Well it flew today. According to the club it was a success. Just waiting for the video.

:wave::clap::headbang:

I'm glad it was a success! I wonder what'll happen to that big sucker now. It might be a tad large to store in your garage.

A couple pics up here.

Not fantastic pics, but a glimpse. The V2 was definately not a threat to the waiver.

that's excellent!

one heck of a neat flight. Greta job guys.

dgreger said:

Although it is pretty cool, i still think it pales in comparison to the current record holder Steve Eves and his Saturn V, at 1:10 scale it was 38ft tall and weighed over 1600lbs and took 1 "P" and 8 "N" motors to a little over 4400ft.
View attachment 257504

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I have to agree. Steve's rocket was so powerful and so impressive on liftoff. And it was a work of art, too.

It is an impressive build. I want to see it go ROOOOOOOAAAAAAARRRR up to a few thousand feet, though.

[video=youtube_share;xzcxEXHdHx0]https://youtu.be/xzcxEXHdHx0[/video]

i would propose a powerfull hybrid cluster for the next flight...

There is another, shorter and somewhat grainy video of this launch on the NAR Facebook page. It looks to me like the fin can/booster section took a bit of a hard landing. Other than that it was pretty darned spectacular! (Kinda hard to beat that perfect set down of Steve Eaves masterpiece.)

I think this V2 needs the 6x O-6300 hybrid cluster that was used during the epic Top Gear Robin Reliant Space Shuttle Challenge on BBC a couple of years ago...

[video]https://youtu.be/pJdrlWR-yFM[/video]

Congratulations to everyone involved in the project! Wunderbar!

Very cool, but I would have liked to see a better paint job on that.

My top men high power friends tell me to "Go BIG or go home." Now I really get what they are talking about.