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 61 users online :: 4 registered, 0 hidden and 57 guests


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

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Cartridge Concept (Oxygen+Fuel "Hybrid")

Post questions and info about hybrid (compressed gas with fuel) powered cannons here. This includes discussion about fuels, ratios, ignition systems, build types, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: jackssmirkingrevenge » Wed Oct 13, 2010 2:17 am

Read about it, but I have access to a lot more stainless material than I do lantern batteries though...
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: saefroch » Wed Oct 13, 2010 6:51 am

:oops: I did read the thread, just somehow I missed that you specified the power source.

You might be able to use stainless steel electrodes if you can get the voltage down really low (like 2V). IMHO, graphite is the material of choice for inert electrodes, unless you're going to coat the stainless steel with something, and unfortunately all the coatings I can think of are very insulating.

I've just used pencils in the past...
  • 0

User avatar
saefroch
Major General
Major General
 
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map
Country: United States (us)
Reputation: 0

Unread postAuthor: Ragnarok » Wed Oct 13, 2010 7:04 am

saefroch wrote:Who ever said anything about "cells"?

I was talking about electrolysis cells, not electrical cells (or batteries, as they are generally - although technically incorrectly - known).
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jackssmirkingrevenge » Wed Oct 13, 2010 10:23 am

Electrolysis setup v.2 to be tested soon, 2 litre bottle this time and 2 large stainless steel bolts as electrodes, appendages crossed :)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Heimo » Wed Oct 13, 2010 1:03 pm

jackssmirkingrevenge wrote:Thanks for the tips :) is there a cheap plentiful source of graphite that doesn't involve me dismembering pencils though? Or another suitable electrode material? Can I go with stainless steel then ethically dispose of the electrolyte in an environmentally friendly manner?


a easy way to get your hands on some graphite rods is to buy some woodless graphite pencils from a art supply (I have no idea what they cost though)

Image
  • 0

The voices in my head may not be real, but they have some good ideas!
User avatar
Heimo
2nd Lieutenant
2nd Lieutenant
 
Posts: 242
Joined: Sun Oct 25, 2009 3:02 pm
Reputation: 0

Unread postAuthor: Fnord » Wed Oct 13, 2010 3:01 pm

is there a cheap plentiful source of graphite that doesn't involve me dismembering pencils though?


No.
Buy a bunch of cheap pencils from the dollar store and burn them.
You have to take a material's properties into consideration before you begin an otherwise laborous task :)

Though you may want to clean them afterwards; you know... scrub the carbon off the carbon.

I put some nice electrodes together in 30 minutes like this.

Edit... Though you might try carbon fiber. It's expensive, but you may be able to get it for free if you can find some broken fishing poles or arrow shafts. Have any sporting-goods stores nearby?
  • 0

Image
User avatar
Fnord
Major General
Major General
 
Posts: 2244
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Reputation: 7

Unread postAuthor: psycix » Sun Oct 17, 2010 4:52 am

I once opened up about 20 zinc-carbon AA batteries for the carbon rods.

Besides being a PITA to get them out and to clean them, they break up due to bubbles forming inside the surface.
Go with stainless steel instead.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: inonickname » Sun Oct 17, 2010 8:08 am

Use stainless steel. Make sure you have plenty of area as well. Use sheets (buy them, or make them-cut up a cheap bit of stainless cookware) and NaOH or sodium/potassium carbonate as an electrolyte. Graphite will just fall to crud and doesn't work real well. Also, make your electrolyte fluid have as much volume as you can, to keep the system cool (and more efficient). By the way, anyone who starts banging on about hexavalent chromium coming off into the solution from the stainless electrodes is an idiot :roll:


I wonder why you don't use the H2/O2 mix as it is? It's stoichometric, will ignite in a large range (so if you have anything that affects the mix, it shouldn't be a problem) and will be a more effective fuel, particularly for light projectiles. (especially for light projectiles, water is a much lighter propellant gas than CO2, and hydrogen/oxygen mixtures have a FAST flame front.

If you don't try it...I will...I think I can get SOS with an atmospheric pressure mix and a suitable projectile (and launcher).
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: Ragnarok » Sun Oct 17, 2010 9:06 am

inonickname wrote:I wonder why you don't use the H2/O2 mix as it is?

Using GasEq and a rich product set:

Peak pressure of atmospheric H2/O2 mix: 9.8 atm (absolute pressure)
Peak Pressure of atmospheric butane/O2 mix: 18.7 atm (absolute pressure)

Does that answer your question?
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jackssmirkingrevenge » Sun Oct 17, 2010 11:59 pm

Fnord wrote:Though you might try carbon fiber. It's expensive, but you may be able to get it for free if you can find some broken fishing poles or arrow shafts. Have any sporting-goods stores nearby?


you'd need the raw carbon fibre though, wouldn't an arrow shaft or fishing pole be encased in resin and therefore insulated?

In any case, the electrolysis project is on hold while I concentrate on other projects.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: inonickname » Mon Oct 18, 2010 3:25 am

Ragnarok wrote:
inonickname wrote:I wonder why you don't use the H2/O2 mix as it is?

Using GasEq and a rich product set:

Peak pressure of atmospheric H2/O2 mix: 9.8 atm (absolute pressure)
Peak Pressure of atmospheric butane/O2 mix: 18.7 atm (absolute pressure)

Does that answer your question?


We both know pressure isn't everything..With lighter projectiles, the higher flame front speed, higher temperature and lower density propellant gas are going to pay dividends.
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: Insomniac » Mon Oct 18, 2010 7:00 am

Pencils and the like arn't as good as the carbon rods from electrical cells, as they tend to have additives to adjust the hardness which makes them less suitable. Though even the ones from lantern batteries fall apart pretty quickly due to the bubbles wearing them away.
  • 0

I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
User avatar
Insomniac
Major General
Major General
 
Posts: 1297
Joined: Mon Dec 18, 2006 3:47 pm
Location: Australia
Country: Australia (au)
Reputation: 0

Unread postAuthor: Ragnarok » Mon Oct 18, 2010 9:46 am

inonickname wrote:We both know pressure isn't everything.

It isn't everything, but the higher temperature and lower density gas just aren't going to be relevant at these relatively low mach numbers (in the propellant, that is), and will more likely result in greater heat loss - hence, the pressure is more use.

H2/O2 mixes will have their advantages - when the pre-ignition pressure is increased to make up for their relatively low post-ignition pressure.
I would imagine the first mile a second hybrid might well be H2/O2 based, but I can't see it being a big hit in atmospheric systems.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Previous

Return to Hybrid Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'