Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 60 users online :: 4 registered, 0 hidden and 56 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Majestic-12 [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

stupid 2 Stage rocket prototype design...

All non-spudgun related discussion goes here such as projects, theories, serious questions, etc. All "off-topic" posts (aka useless posting, determined by moderators) will be removed.
Sponsored 

Lift off?

Poll ended at Wed Oct 15, 2008 4:27 pm

Yes!
3
20%
Noo!
5
33%
It will lift off only because it will explode!
7
47%
 
Total votes : 15
  • Author
    Message

Unread postAuthor: Demon » Fri Oct 10, 2008 5:48 pm

Hur? Where do you get $300 and titanium and dangerous propellants? The one I saw used some PVC, some N20, and some ABS shavings.


Well, hybrid rocket produce a lot of power and pvc is not designed for that...
  • 0

User avatar
Demon
Colonel
Colonel
 
Posts: 743
Joined: Sun Apr 13, 2008 8:46 am
Reputation: 0

Unread postAuthor: TurboSuper » Fri Oct 10, 2008 5:51 pm

Seemed to work for this dude:

http://www.intertlan.com/cohetes/hybrids/
  • 0

"If at first you dont succeed, then skydiving is not for you" - Darwin Awards

TurboSuper
Brigadier General
Brigadier General
 
Posts: 986
Joined: Thu Jun 16, 2005 1:44 pm
Reputation: 0

Unread postAuthor: Demon » Fri Oct 10, 2008 6:07 pm

I will rather make this one for a first time :D
  • 0

Attachments
simple pvc rocket motor.JPG
If you Mods think that there is any against rules purposes, delete it.
User avatar
Demon
Colonel
Colonel
 
Posts: 743
Joined: Sun Apr 13, 2008 8:46 am
Reputation: 0

Unread postAuthor: DYI » Fri Oct 10, 2008 6:35 pm

I see a few problems here. The first is that the PVC "nozzle" will become a full-bore hole in a very short time. The second is that the hole you show is likely too small, and will result in your rocket turning into an expensive, time consuming firework. Somewhere down the list after that are the facts that your rocket design is nowhere close to aerodynamically stable, and that you are using over 3 pounds of propellant in your first attempt at a rocket.

On the subject of hybrid rockets: While the technology is perfectly accessible to the average hobbyist (and you certainly don't need titanium, tungsten, or any particulary dangerous materials), oxidisers can get expensive. For the small scales that most sane amateurs would be working with, this isn't particulary problematic. When you're using almost 10kg of fuel alone, well... :roll:
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: mark.f » Fri Oct 10, 2008 7:20 pm

What's wrong with cardboard (Kraft) tubing and bentonite clay?
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: ammosmoke » Fri Oct 10, 2008 10:04 pm

Has anyone here gone to jamesyawn.com? The guy has already solved all your problems and more. He makes nozzles from aluminum, and well... he is just brilliant.
  • 0

<img>http://www.speedtest.net/result/309559995.png</img>
User avatar
ammosmoke
Brigadier General
Brigadier General
 
Posts: 1011
Joined: Wed Sep 27, 2006 10:57 am
Reputation: 0

Unread postAuthor: Demon » Sat Oct 11, 2008 6:55 am

you are using over 3 pounds of propellant in your first attempt at a rocket.


What????

This model just use approx 50 grams of very basic fuel...
  • 0

User avatar
Demon
Colonel
Colonel
 
Posts: 743
Joined: Sun Apr 13, 2008 8:46 am
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: DYI » Sat Oct 11, 2008 11:04 am

What????

This model just use approx 50 grams of very basic fuel...


The diagram says, very distinctly, 550g of KNO<sub>3</sub> and 1kg of sugar. That's 1.55kg, or about 3.41 pounds. You might want to take a look at the plan YOU posted before making comments :P
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: Demon » Sat Oct 11, 2008 11:28 am

???okay, try to put 3 lbs in a 1 inch x 6 inch pvc pipe.

I dont know exactly how i need, so i make more fuel then i need, thats seem logic for me.
  • 0

User avatar
Demon
Colonel
Colonel
 
Posts: 743
Joined: Sun Apr 13, 2008 8:46 am
Reputation: 0

Unread postAuthor: ammosmoke » Sat Oct 11, 2008 1:07 pm

Ahem. Is anyone listening to me?
  • 0

<img>http://www.speedtest.net/result/309559995.png</img>
User avatar
ammosmoke
Brigadier General
Brigadier General
 
Posts: 1011
Joined: Wed Sep 27, 2006 10:57 am
Reputation: 0

Unread postAuthor: TurboSuper » Sat Oct 11, 2008 2:14 pm

Welp, guess you should just give it a try. Just hide behind something in case it decides to go in an odd direction.
  • 0

"If at first you dont succeed, then skydiving is not for you" - Darwin Awards

TurboSuper
Brigadier General
Brigadier General
 
Posts: 986
Joined: Thu Jun 16, 2005 1:44 pm
Reputation: 0

Unread postAuthor: Lentamentalisk » Sat Oct 11, 2008 4:38 pm

Thanks so much for the link ammo, I found that incredibly helpful.

btw, I found something that looks absolutely perfect for my nozzle. I have no clue what it was, I just found a box of them at the local junk yard type place, for next to nothing. They seem to be from plumbing of some sort, these little porcelain 3/4" doodads that look like perfect nozzles.
  • 0

Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Lentamentalisk
Brigadier General
Brigadier General
 
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.
Reputation: 0

Unread postAuthor: SEAKING9006 » Sat Oct 11, 2008 7:11 pm

Does everyone in this thread live outside the U.S. or something? Because last I heard, Potassium Nitrate is HEAVILY regulated here in the 'States.
  • 0

Completed projects:
CA1 SMSS Basic Inline
CA3 PDAB Airburst Cannon

Current Project: Bolt action rifle (25x140mm + 1in shot)

SEAKING9006
Colonel
Colonel
 
Posts: 734
Joined: Mon Jun 23, 2008 3:20 pm
Location: Texas
Reputation: 0

Unread postAuthor: Lentamentalisk » Sat Oct 11, 2008 8:30 pm

not at all. Potassium Nitrate is a regular fertilizer. I couldn't find any at my local OSH, but then I read that stump remover is like 98% KNO3, though it is $5 a lb... Transport of Rcandy fuel is quite possibly illegal across state lines, but that is a whole nother deal.

Here are some pics of my rocket casing prototype. I used an old "nob and tube" electrical insulator for the nozzle, as it is a perfectly shaped porciline nozzle.
Image
Image
The hose clamps are holding the nails on, which hook around the end of the nozzle, for an attempt at a physical connection.
I know they must go before I actually get around to launching it, but they will do for now.
  • 0

Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Lentamentalisk
Brigadier General
Brigadier General
 
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.
Reputation: 0

Unread postAuthor: Demon » Sun Oct 12, 2008 11:02 am

i just went to rona, based on the plans just there ^.
  • 0

Attachments
Photo 031.jpg
Rocket!
Photo 032.jpg
rocket butt!
Photo 032.jpg (27.93 KiB) Viewed 223 times
User avatar
Demon
Colonel
Colonel
 
Posts: 743
Joined: Sun Apr 13, 2008 8:46 am
Reputation: 0

PreviousNext

Return to Non-Spudgun Related Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Majestic-12 [Bot], Yahoo [Bot]

Reputation System ©'