Author Topic: Not CL But Very Cool! (Read 19097 times)

Les McDonald · « **on:** February 28, 2015, 09:02:13 AM »

When I worked at Orange Blossom Hobbies the Car Dept guys would build and launch, in the parking lot, something "rocket motor propelled" every Saturday after we closed. Thankfully nothing like this!

https://www.youtube.com/embed/pD_yQZ4iNjY?rel=0

Akihiro Danjo · « **Reply #1 on:** February 28, 2015, 11:57:34 AM »

Everything was beyond my imagination!

Bill Morell · « **Reply #2 on:** February 28, 2015, 12:25:47 PM »

That is really cool. However, here in America that would be construed as a "terrorist" act.

Randy Cuberly · « **Reply #3 on:** February 28, 2015, 01:27:59 PM »

I'm absolutely amazed that they could possibly make the thing that stable. I would have expected it to go careening off into the landscape!!!

Just plain fun I suppose with no apparent purpose except excitement!

Randy Cuberly

Jim Kraft · « **Reply #4 on:** February 28, 2015, 01:37:34 PM »

Was Gary Weaver in on it? Looks like something he would do. He comes up with some very entertaining things.

Dan McEntee · « **Reply #5 on:** February 28, 2015, 03:06:59 PM »

This video has been posted here before, but I just watched it again........TWICE! Just something really neat about it. I wonder what they used for rockets? Surplus RATO units? Ship to shore or ship to ship rescue line rockets? Ordinary fireworks? They did use long handled torches to light fuses, so maybe were common or even home made fireworks rockets? Wonder how they deployed the chute? What did it weigh? How high do you think it got, 500 to 700 feet? You can see the one guy trying to help it build up spinning speed before they got the heck out of the way. Really simple, but really cool!
Type at you later,
Dan McEntee

kenneth cook · « **Reply #6 on:** February 28, 2015, 04:06:16 PM »

That was absolutely cool, I do think that would get you arrested however.

wwwarbird · « **Reply #7 on:** February 28, 2015, 05:40:01 PM »

Quote from: Randy Cuberly on February 28, 2015, 01:27:59 PM

I would have expected it to go careening off into the landscape!!!

The first 20 or 30 of them probably did.

Norm Faith Jr. · « **Reply #8 on:** March 01, 2015, 01:10:29 AM »

Celebrating New Year's in Thailand. By all probability the rockets were powered with a form of "home brew" black powder. This "helicopter" is well engineered, balanced and trimmed. It appears to be made so well, that it is recoverable. I watched four guys one afternoon in Thailand, sitting on a bamboo mat with mortars and pestles grinding charcoal. Two of them were working the mortars and the other two were mixing the other ingredients, I was made to understand were salt-peter and sulfur. What was "striking" about this scene, was that all four of them were smoking Thai cigars. Needless to say...I kept my distance. BTW...Later that day, I got to shoot my brother-law's muzzle loader with some of that very powder. It worked quite well.
Norm

Les McDonald · « **Reply #9 on:** March 01, 2015, 11:41:07 AM »

"Back in the day" I was stationed at Udorn Air Base in Thailand and spent alot of time hanging out with Thai guys at the local Honda shop.
I went on some great motorcycle rides with them and I can envision those guys working on something like this giant pinwheel.
The Thai people were friendly, hard working, smart and enjoyed messing around with stuff just like we do.

Brett Buck · « **Reply #10 on:** March 01, 2015, 11:56:43 AM »

Quote from: Dan McEntee on February 28, 2015, 03:06:59 PM

This video has been posted here before, but I just watched it again........TWICE! Just something really neat about it. I wonder what they used for rockets? Surplus RATO units? Ship to shore or ship to ship rescue line rockets? Ordinary fireworks?

   I am amazed they got it to work, it's quite impressive both from an overall design standpoint but also from a propulsion standpoint. I don't think it's any standard fireworks rockets, because the burn time is *far* too long for conventional fireworks rockets, or most conventional munitions. Conventional fireworks rockets work only because the burn time is so short that they don't heat up and catch fire/self destruct/erode the nozzle before burn out. With a 60-ish second burn time you have to consider the heat soakback. There aren't any HPR or modroc engines with that kind of burn time. It's much more like a Jetex motor.

   I can envision how to do it with very low burn rate AP propellant (where's Gary Weaver when you need him...) like Aerotech "Blackjack" but the engines would be custom and not trivial. You might be able to use some of the very low thrust RC Boost-glider motors in series staging but I don't see that in the video and it would be a nightmare for reliability. I can imagine that someone can manage with BP propellant in custom motors but I certainly don't know how to do it. An alternative might be something like Sidewinder/Shillelagh missile engines. It's also impressive that they managed to arrange for a viable recovery system. Even with modern techniques, this is the Achilles Heel of HPR models.

   But, I have to say, I am not sure how they did it successfully, and I don't know how I would go about it, either.

   Brett

Ward Van Duzer · « **Reply #11 on:** March 01, 2015, 02:15:16 PM »

Estes, EAT YOUR HEART OUT !

Ward-O

Norm Faith Jr. · « **Reply #12 on:** March 01, 2015, 06:16:10 PM »

Brett really tweaked my curiosity. I'm going to get a hold of my nephew up in the North East of Thailand and see if he can track down the people who built it. I let you all know if I find out something.
Norm

Norm Faith Jr. · « **Reply #13 on:** March 01, 2015, 06:46:37 PM »

Got this almost right away...If you can open the video, it will show you how a smaller scale version is constructed. As Les said "it's not control line," but it is modelling of a sort. I promise more to come.
Norm
http://sploid.gizmodo.com/these-are-the-coolest-amateur-rockets-ive-ever-seen-1594656055

Jason Greer · « **Reply #14 on:** March 01, 2015, 06:55:08 PM »

Here is another small scale version with some nice onboard camera footage. Seems these are also known as a Girandola.

Brett Buck · « **Reply #15 on:** March 01, 2015, 07:05:55 PM »

Quote from: Jason Greer on March 01, 2015, 06:55:08 PM

Here is another small scale version with some nice onboard camera footage. Seems these are also known as a Girandola.

I could see how to make that one with typical fireworks techniques (particular since we have a movie of it). I guess the part that stumps me on the big one is getting that kind of burn time with effective thrust using fireworks techniques.

Brett

Norm Faith Jr. · « **Reply #16 on:** March 01, 2015, 07:06:12 PM »

Here is one more, I'm being told that they can get up to 4 minute burns. The make their own nozzles...They are called "Bun Bang Fai."

Steve Fitton · « **Reply #17 on:** March 01, 2015, 09:26:18 PM »

Seeing that last video makes me wonder if they have figured out some propellants other than black powder such as a sugar motor or some other similar chemistry. The flame and the plume might be black powder but to me they look a bit more like some crude type of composite formulation.

Brett Buck · « **Reply #18 on:** March 01, 2015, 10:23:01 PM »

Quote from: Steve Fitton on March 01, 2015, 09:26:18 PM

Seeing that last video makes me wonder if they have figured out some propellants other than black powder such as a sugar motor or some other similar chemistry. The flame and the plume might be black powder but to me they look a bit more like some crude type of composite formulation.

I am not sure why you think it is crude. People in Thailand have more-or-less the same resources you and I do and might have less regulation to deal with. The exhaust looks a lot like Aerotech Blackjack to me, but it's far more burn time than any commercial HPR motor.

I guess they probably made their own motors using some sort of slow-burn AP, but they are darn big and burn a very long time.

Brett

Brett Buck · « **Reply #19 on:** March 01, 2015, 10:27:02 PM »

Quote from: Norm Faith Jr. on March 01, 2015, 07:06:12 PM

Here is one more, I'm being told that they can get up to 4 minute burns. The make their own nozzles...They are called "Bun Bang Fai."

That one is even more impressive, I am surprised it doesn't fly apart.

Whatever they are doing, and however they are doing it, it's magnificent!

Brett

Mike Griffin · « **Reply #20 on:** March 02, 2015, 12:01:41 PM »

I think I saw Dan Banjok on the launch pad.

Steve Fitton · « **Reply #21 on:** March 03, 2015, 06:02:54 AM »

Quote from: Mike Griffin on March 02, 2015, 12:01:41 PM

I think I saw Dan Banjok on the launch pad.

Imagine the mayhem if Banjock and Gary Weaver collaborated on a project...!

"crude" as far as the motors the guys in the video made is relative I guess. The Thai dudes remind me of the guys in the Khyber Pass that can make an AK-47 out of some scrap metal. I agree its hard to guess what they are doing, but the end result are some impressive engines.

The link goes to a Daily Mail article that looks like a less successful launch from the same location. Thinking about their ignition techniques makes me think the motors are black powder after all.

http://www.dailymail.co.uk/travel/travel_news/article-2910237/Rocket-festival-Thailand-takes-dangerous-turn-launch-procedure-goes-horribly-wrong.html

frank williams · « **Reply #22 on:** March 03, 2015, 08:56:30 AM »

Absolutely beautiful! Lets talk gyro precession .... I love the big Oooooohhhhhhh as the chute opens .....

Steve Fitton · « **Reply #23 on:** March 03, 2015, 11:54:22 AM »

Turns out that the motors are indeed crude by our standards, but obviously highly effective. Black powder endburners using PVC casings with bamboo liners and wooden nozzles. It seems to be the Thai/Laotian equivalent of the US LDRS/Balls launch. The Wiki article cited some of the rockets in the 120kg+ weight category, which is impressive indeed for black powder.

I find their using wood for the nozzle to be quite clever. Easy to fabricate and a good ablator.

Thinking about Les's original comment about the Orange Blossom Hobby car guys makes me think about the video Jake Moon did of his rocket powered car...its awesome!

frank williams · « **Reply #24 on:** March 03, 2015, 01:30:17 PM »

We ask the Chinese, after one of their first successful launch and capsule entrys, what they used for ablator on the capsule? ...... the answer .. Oak

Norm Faith Jr. · « **Reply #25 on:** March 03, 2015, 09:02:36 PM »

Quote from: frank williams on March 03, 2015, 08:56:30 AM

Absolutely beautiful! Lets talk gyro precession .... I love the big Oooooohhhhhhh as the chute opens .....

" I love the big Oooooohhhhhhh as the chute opens." A wonderful "Thai mannerism."

Norm

Brett Buck · « **Reply #26 on:** March 03, 2015, 09:06:26 PM »

Quote from: frank williams on March 03, 2015, 01:30:17 PM

We ask the Chinese, after one of their first successful launch and capsule entrys, what they used for ablator on the capsule? ...... the answer .. Oak

Exactly, and I always thought that it was a borderline brilliant. I guarantee it costs less and probably weighs less than Avcoat 5026. The only downside I see is difficulty with quality control, since it is not an engineered product.

Brett

FLOYD CARTER · « **Reply #27 on:** March 05, 2015, 06:16:23 PM »

As a high school juvenile delinquent, I made my own gunpowder. Almost, but not quite, equal parts by volume, potassium nitrate, sulphur, and charcoal. I had to make my own charcoal by burning hardwood in an oxygen-starved brick oven. Potassium nitrate was actually easy to get mail order (but not these days).

Tried making a big firecracker packed in a paper tube. Never got one to explode very big. Think the powder wasn't packed tight enough. Getting a reliable fuse was hardest part.

F.C.

Brett Buck · « **Reply #28 on:** March 05, 2015, 06:27:41 PM »

Quote from: FLOYD CARTER on March 05, 2015, 06:16:23 PM

Tried making a big firecracker packed in a paper tube. Never got one to explode very big. Think the powder wasn't packed tight enough.

Probably wasn't milled enough.

Brett