Monster Sprayer Combustion Cannon

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
200BAR
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Thu Sep 14, 2017 10:04 am

ImageP1070488 by Terry Griffiths, on Flickr

https://www.flickr.com/photos/154623046 ... ed-public/

Collecting bits for a while, finally got round to putting them together. Mostly all used parts.
Spec:
8ltr high pressure sprayer bottle for combustion chamber(inc bends likely 10ltr)
2m long 44mm bore aluminum barrel
BBQ sparker ignition
12v Air bed blower to vent chamber
12v drill battery powers blower
Metered propane via regulator
Stainless exhaust pipe bends
Barrel opens via stainless sanitary flange fitting/clamp
Laser dot sight

Just made it up as i went along using the bits i had, no fancy calculations etc. The combo of large combustion chamber and long barrel seem to have worked. It has crazy power and chucks spuds through finish grade 3/4 plywood and golf balls clean through oil drum without it even moving :shock: See damage pics

ImageP1070487 by Terry Griffiths, on Flickr
ImageP1070486 by Terry Griffiths, on Flickr
ImageP1070485 by Terry Griffiths, on Flickr
ImageP1070484 by Terry Griffiths, on Flickr
ImageP1070483 by Terry Griffiths, on Flickr
ImageP1070482 by Terry Griffiths, on Flickr
ImageP1070481 by Terry Griffiths, on Flickr
ImageP1070480 by Terry Griffiths, on Flickr
ImageP1070490 by Terry Griffiths, on Flickr
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jackssmirkingrevenge
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Thu Sep 14, 2017 11:34 am

Image

Big is good, impressive build! Integral blower is a nice touch.
hectmarr wrote:You have to make many weapons, because this field is long and short life
200BAR
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Fri Sep 15, 2017 6:25 am

Thanks. I didn't want to compromise the tank by cutting a big hole in it for an internal fan and vent valve so the blower was what came to mind. It works rely well, run it for a couple of seconds and chamber is all vented. It blows air in to the chamber via the metering pipe and is isolated by means of a second ball valve.
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jackssmirkingrevenge
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Fri Sep 15, 2017 9:19 am

200BAR wrote:isolated by means of a second ball valve
I noticed that, smart move!

Do you fire it from the hip or is that fancy handle just for transport?

I really love this particular angle by the way :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
200BAR
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Fri Sep 15, 2017 11:40 am

The idea is that it can be fired from the hip...not actually done it yet but will give it a go at the weekend...i have gathered a pile of stuff that is just begging to be destroyed :)
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mark.f
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Thu Sep 21, 2017 11:53 pm

4UBr2fu.jpg
I, too, like the blower system. Ducting it through the meter pipe is something new (although compressed air through the meter is something I've seen in hybrids a lot).

If you can't fit a fan in it, it could use some "chamber change". :D It's just random objects inside the chamber you can shake up before firing to mix the fuel and air. The over/under design lends itself well to such things (because they don't fly out that easily).

Good job!
200BAR
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Fri Sep 22, 2017 2:59 am

Thanks. Seems to fire every time as long as the pressure in the meter pipe is 35psi and gives consistent power shots. I guess the swoosh of gas out of the mete pipe into the chamber is enough to mix it up. I might try some "chamber change" to see if it makes any difference in performance. I will chrony it when i get the time.

@ JSM- I tried a few shots form the hip and it works good and feel pretty cool toting it like a pirate :)
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jackssmirkingrevenge
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Sun Sep 24, 2017 5:36 am

mark.f wrote:I, too, like the blower system.
Your appreciation is now the thread thumbnail :D
200BAR wrote:I tried a few shots form the hip and it works good and feel pretty cool toting it like a pirate
ARRRRRRRR!!!!
hectmarr wrote:You have to make many weapons, because this field is long and short life
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mark.f
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Sun Sep 24, 2017 3:46 pm

jackssmirkingrevenge wrote:Your appreciation is now the thread thumbnail :D
Another reason to use the uploader I guess. :D
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farcticox1
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Sun Sep 24, 2017 4:13 pm

Your appreciation is now the thread thumbnail :D


How do I do that :o :shock: :( :?
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jackssmirkingrevenge
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Tue Sep 26, 2017 4:15 am

farcticox1 wrote:How do I do that :o :shock: :( :?
If I remember well you can only select thumbnails for the showcase section.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Air2theBrain
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Tue Nov 28, 2017 6:36 am

Wow mind blown. 8) :twisted:

That is one wicked cannon you have there!

EDIT-Looks very accurate also. 8)

Love it well done! :wink:
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