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 58 users online :: 6 registered, 0 hidden and 52 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Sound levels

Post questions and info about combustion (flammable vapor) powered cannons here. This includes discussion about fuels, ratios, ignition systems, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: battlelava » Mon May 07, 2012 6:46 pm

I tried it again, filled the syringe to the Max placed as far in as it can go and quickly repeated. It went off after 15+ ignition attempts. Not enough power to move the projectile even an inch. Retried with spray and pay and it launched 10 feet
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: Lockednloaded » Mon May 07, 2012 7:29 pm

battlelava wrote:
jackssmirkingrevenge wrote:video of what you're doing to fuel? are you sure the measurements are correct? are you venting between shots?


I did it exactly like it was done in the syringe pages video. In between injecting fuel (because i have a 10ml syringe) I placed the cap on the end and only removed to inject more fuel. I did 2 10ml injections and 1 3.5ml injection. I then waited for the fuel to mix. In between shots I took out the projectile, sprayed the air duster through it and left it there for roughly 5 minutes to completely air out.

I was so let down, and its probably a stupid problem too.


Wait, I thought it was decided that air dusters don't actually use real air, and therefore would purge the nesescary oxygen from the chamber for combustion to occur?
  • 0

I love lamp
User avatar
Lockednloaded
Major General
Major General
 
Posts: 1558
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Reputation: 0

Unread postAuthor: battlelava » Mon May 07, 2012 8:01 pm

Lockednloaded wrote:
battlelava wrote:
jackssmirkingrevenge wrote:video of what you're doing to fuel? are you sure the measurements are correct? are you venting between shots?


I did it exactly like it was done in the syringe pages video. In between injecting fuel (because i have a 10ml syringe) I placed the cap on the end and only removed to inject more fuel. I did 2 10ml injections and 1 3.5ml injection. I then waited for the fuel to mix. In between shots I took out the projectile, sprayed the air duster through it and left it there for roughly 5 minutes to completely air out.

I was so let down, and its probably a stupid problem too.


Wait, I thought it was decided that air dusters don't actually use real air, and therefore would purge the nesescary oxygen from the chamber for combustion to occur?

I let it sit for 5 mins afterwards to air out further. Obviously with both ends open
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: DYI » Mon May 07, 2012 9:00 pm

First off, I must say this is a pretty dodgy looking thread.

To solve your problem:
-MEASURE the chamber volume.
-DO NOT "vent" the chamber with inert or flammable gases. Vent it with AIR.
-Inject about 4.5% of the chamber volume in propane in such a way that half of it doesn't leak out before you replace the cap (use a fueling port, don't take the cap off)

Finally, just try it with a potato and see how that works. Develop fancy ammo out of cardboard tubes and tape afterwards... :roll:


To everyone eager to correct my fueling percentage: don't bother. I intended nothing different.
  • 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: battlelava » Mon May 07, 2012 9:30 pm

Before I screw up something else, for a filling port can I take put another screw in.

I'll use a potato, exactly 24.5ml of propane. I'll let it mix for 10 minutes and then ill give it a go. I'll also try to video tape the whole thing.
Image

I was never good with stoichometry (can't even spell it lmao) :D
I don't even think i balance the equation correctly
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Mon May 07, 2012 11:57 pm

What the man said, I agree with everything DYI stated, except:

DYI wrote:Inject about 4.5% of the chamber volume in propane


You should not try in inject your chamber volume into the propane, this will only dilute your fuel.
  • 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: DYI » Tue May 08, 2012 7:47 am

You should not try in inject your chamber volume into the propane, this will only dilute your fuel.


"In inject"? Really Jack? If you're being all persnickety about grammar, you should make a special effort to check for things like that :lol:

Alright, let's reword this: "Fill a syringe with an amount of propane which will, at current ambient conditions, occupy a volume equal to 0.045 times that of the chamber volume. Then inject this amount into the chamber".

Happy now, Jack? :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

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Tue May 08, 2012 8:06 am

I was trying a double bluff where you would expect me to say "OI! 4.19%!" but I didn't, so I picked on something else, but clearly I failed miserably.

Image
  • 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: DYI » Tue May 08, 2012 8:15 am

I figured that's what you were up to, but seeing the above test where he failed to notice the 1:1 correspondence between NaOH and NaCl, I fear he may fail to notice the jest as well :lol:
  • 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: battlelava » Tue May 08, 2012 9:13 am

well this is what i have to show for myself, mind my overhairy legs I only have 2 hands

http://www.youtube.com/watch?v=7PbzI2Bjj74

waited a few minutes with some shaking

http://www.youtube.com/watch?v=6mC331sUwj4


Edit: So i recorded all of that 20 minutes ago, I just retried it and it went off. Moved the projectile about 20 inches in a 24 inch barrel
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Tue May 08, 2012 12:00 pm

You seem to be doing it right.

So the chamber and barrel are same tube?

stupid question, are you loading the projectile before fuelling?

are you sure about the dimensions?
  • 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: battlelava » Tue May 08, 2012 12:15 pm

jackssmirkingrevenge wrote:You seem to be doing it right.

So the chamber and barrel are same tube?

stupid question, are you loading the projectile before fuelling?

are you sure about the dimensions?


loading it before fuelling, i forgot to show the photo of a light at the muzzle pointed up to show it was 100% airtight.

I don't have a digital caliper but I used a measuring tape and found it to be 1 7/8 (1.875) (I think i will go double check) which is pritty close to 1.9 and i measured it on a ramrod to set the projectile.
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: DYI » Tue May 08, 2012 12:20 pm

I see you've still failed to implement a fueling port. What type of pipe is this? Checking the standard dimensions will be more useful than trying to measure an internal diameter with a tape measure (that is assuming that you continue to refuse to MEASURE THE VOLUME DIRECTLY).

Another stupid question: You're not pulling up the plunger on the syringe to "fill" it, are you? It appears you're restricting your propane flow with a tiny orifice for no apparent reason, which must cause quite a bit of trouble for filling the syringe.
  • 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: battlelava » Tue May 08, 2012 12:25 pm

DYI wrote:I see you've still failed to implement a fueling port. What type of pipe is this? Checking the standard dimensions will be more useful than trying to measure an internal diameter with a tape measure (that is assuming that you continue to refuse to MEASURE THE VOLUME DIRECTLY).

Another stupid question: You're not pulling up the plunger on the syringe to "fill" it, are you? It appears you're restricting your propane flow with a tiny orifice for no apparent reason, which must cause quite a bit of trouble for filling the syringe.


Standard dimensions are 1.9" . By measuring the volume directly, do you want me to fill it up with water and measure it in a beaker, because i don't have anything precise enough to measure it. I am not touching the plunger at all, its just hard to seal the tip on the propane torch with the syringe tip without gas leaking because it won't fill it then. the propane tip is just a standard benzo fuel without the air mixer top on.
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: DYI » Tue May 08, 2012 12:30 pm

...because i don't have anything precise enough to measure it.


You have a syringe :wink:

Standard dimensions are 1.9"


You still haven't said what type of pipe it is.

Also, I suspect you're losing a lot of propane by having to open the breech several times. Tap pipe threads into the thicker section at the breech and stick a small ball valve on there - that'll free you from having to open the breech to fuel. Alternatively, just get a larger syringe.

Finally: I recognize the propane fitting, I'm just curious as to why you didn't unscrew the orifice from the rest of the valve to get the full flow it's capable of.
  • 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

PreviousNext

Return to Combustion Cannon Discussion

Who is online

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

Reputation System ©'