Search found 67 matches

by joe blogs
Thu May 21, 2009 12:45 am
Forum: Pneumatic Cannons
Topic: marblematic mk 3
Replies: 10
Views: 5116

Hey all, I'm in a tight financial spot with my latest combustion cannon. I have decided to sell this marble sniper and an assortment of fittings, pipes and optics. Is there somewhere "spud related" i can make that post?. Would it be alright if i make that post in pneumatic discussion and donate some...
by joe blogs
Sun May 17, 2009 5:57 am
Forum: Combustion Cannons
Topic: Gathering info
Replies: 1
Views: 1023

Gathering info

Where some people mount their fans in cannons is puzzling. Doesnt having the fan between the sparks and the barrel subject it to lots of escaping pressure? do you count the volume of the complete fan assembly (fan and vent tube) or just the wall thickness of the vent tube and the fan in your ratio c...
by joe blogs
Sun May 17, 2009 4:23 am
Forum: Pneumatic Cannons
Topic: marblematic mk 3
Replies: 10
Views: 5116

Sorry i wasnt aware of the "game" issue i will edit it out. I live on the east coast of Australia and it is fairly tropical here. The scope is ussually set to 5x40 on this pneumatic but i always have the 9x40 option when i put it on my .303.
by joe blogs
Fri May 15, 2009 5:39 am
Forum: Pneumatic Cannons
Topic: marblematic mk 3
Replies: 10
Views: 5116

marblematic mk 3

This is my latest installment (made about 4 months ago but wanted to credit it the proper writeup) . the spec are # 50mm chamber 60cm chamber #40 mm sprinkler valve #16 mm,70cm barrel #High flow sandblasting vent valve. #zoomable 3-9x40 tasco scope. #laser sight #bipod with lipschitz bracket #machin...
by joe blogs
Thu May 14, 2009 7:00 am
Forum: Combustion Cannons
Topic: Parts in Australia
Replies: 24
Views: 6122

If you live in Northern NSW or south Queensland Rural Buying Service is the go. There are cheap quality parts like stainless pressure rated cam locks. The ignition, forget about piezo's or electronic BBQ lighters, make a ignition circuit like this one http://www.spudfiles.com/forums/high-power-ignit...
by joe blogs
Thu May 14, 2009 6:48 am
Forum: Combustion Cannons
Topic: Ratio conundrums!!??
Replies: 11
Views: 4416

I am not using the metered syringe as the injection method. if you look at my crappy paint picture you will see that im using a ball valve system to regulate my ignition gas. I am using a 2 ignition coils in anti parrallel to generate seven sparks on a spark strip. the sparks are 1 cm each. Thanks j...
by joe blogs
Thu May 14, 2009 1:10 am
Forum: Combustion Cannons
Topic: Ratio conundrums!!??
Replies: 11
Views: 4416

Does the fan assembly in the bl-520 take up much volume? I plan on making this cannon. http://i152.photobucket.com/albums/s175/joda_cobra/gun.jpg But the fan assembly on the bl-520 looks like this. http://i152.photobucket.com/albums/s175/joda_cobra/gun-1.jpg I hope to understand this as i dont have ...
by joe blogs
Wed May 13, 2009 5:02 pm
Forum: Combustion Cannons
Topic: Ratio conundrums!!??
Replies: 11
Views: 4416

<Those are the formula's for a coax> I sort of did factor in the barrel occoping space. Though i didnt factor in the OD i did factor in the ID which wouldnt make that much difference. This is why the formula L x pi x 2.5^2 - L x pi x 1^2 Notice i minused the barrel algebraic length ie coax formula i...
by joe blogs
Wed May 13, 2009 6:19 am
Forum: Combustion Cannons
Topic: Ratio conundrums!!??
Replies: 11
Views: 4416

Ratio conundrums!!??

I have been wanting to make the bl-520 rear loaded cannon for some time now and that lead me to chamber:barrel ratio's. Below are the calculations for a 2 inch barrel 60 inch long 5 inch chamber unknown length (i assumed that the length would satisfied the minimum,maximum and ideal ratios 0.5,1.2,0....
by joe blogs
Mon May 11, 2009 6:06 am
Forum: Combustion Cannons
Topic: are these materials safe?
Replies: 13
Views: 4001

The plan i have for this cannon is as follow's (advanced?simple?).this is all the simple stuff. i could be bothered drawing up how the cam lock seals well and how everything bolts, screw and glues together i just want to give you an idea of what im doing with this pvc and what do you think i can do ...
by joe blogs
Mon May 11, 2009 3:33 am
Forum: Combustion Cannons
Topic: are these materials safe?
Replies: 13
Views: 4001

are these materials safe?

hi all, ive just got a few parts from the store today and am wondering if they will do. i looked at the wall thickness and tried to get the parts that would match my project but also take the pressure. They are an assortment of different rated bits because some of the very high presure bits didnt ma...
by joe blogs
Sat May 05, 2007 1:42 am
Forum: Pneumatic Cannons
Topic: SVD Pneumunov
Replies: 14
Views: 5062

No it's broken at the moment (on-board pump) i use a compressor atm, I'm trying to fix it atm.
The reason i used a ball valve was it was lying around and the rest of the parts i came across without spending any money, coz they were my dads.
Also the stock is made out of an old rail road sleeper.
by joe blogs
Wed May 02, 2007 12:53 am
Forum: Pneumatic Cannons
Topic: SVD Pneumunov
Replies: 14
Views: 5062

The reason i haven't used a sprinkler valve is simple. Because of the money it costs and thats one thing i hope that will put me in front in this contest. this gun is cheap,ergonomic and has a high performance plus it is accurate. And the batteries for the sprinkler valve have to go somewhere. btw t...
by joe blogs
Mon Apr 30, 2007 6:09 am
Forum: Pneumatic Cannons
Topic: SVD Pneumunov
Replies: 14
Views: 5062

SVD Pneumunov

SVD Pneumunov This is my best gun to date. It’s cheap and accurate plus very robust because of the general design and doesn’t have many parts just like the gun I based it on, the svd dragunov. Without much further ado here’s the spec’s. Specs Barrel : .22 calibre gun barrel or a 16mm marble barrel ...
by joe blogs
Fri Apr 27, 2007 4:24 am
Forum: Pneumatic Cannons
Topic: AMR-1
Replies: 61
Views: 16130

I am questioning if i have any hope of winning the competition thanks to your gun.