SpudFiles

Still lots to do, but not long now......

Is that just a rubber seating schrader valve in the last pic? What are the odds of that flying out once your firing this thing at 100-150PSI?

Nice cannon so far bro.

preety much none you could hang on one of those valves the sprinkler or the schrader will start to leak before it fly's out people use them on hybrids you know besides hes got it going through two layers of pvc nice work watto! keep it up

Dornep wrote:Is that just a rubber seating schrader valve in the last pic? What are the odds of that flying out once your firing this thing at 100-150PSI?

Nice cannon so far bro.

Its got rubber on the other side thats to big to fit through the hole, I wont be firing above 100PSI (I'm a wuss)

I pumped it to 40PSI and crammed a frozen spud down the barrel, I was aiming for a palm tree 30m away and hit it first shot, so I guess the accuracy is good. I thought the potato had been obliterated but when I looked around I found a potato sized hole in the fence, on the other side of the fence there was a dent in next doors shed! The potato ricocheted about 3m and still plowed through a fence made of hardiflex!!! And better yet the hole it left is the shape of Australia!! Next I shot a spud straight into the air, it didn't come down for probably 10 seconds, I lost track of it at one stage, which had me running out the front to make sure it didn't hit my car.

The only problem with it is that after every shot the diaphragm gets stuck in the up position, could this be because the thread of the pipe tap is poking through a little bit and causing it to get stuck on an angle, if you know what I mean. Or do you think some grease on the guide pin would help?

On Thursday I'll be satisfied all the cement has completely cured, and I'll pump it to 80PSI then I'm gunna do a video on youtube.

Heres a list of things I'm planning to shoot at:

A large porcelain cat I found
An old internal door
Ply wood
Watermelon
Glass bottles

i cant wait for the youtube link
Once the cement has dried give this cannon a sweet paint job!!!!
Aussie power!!

Did you leave the spring in it?Thats what makes the diaphram go back into position.If the spring is still in there,jus use some lube on it.I had a problem with one of my valves doing this for no reason which was annoying but a good way to fix it is to wack the side of the valve softy with your hand or elbow ohh and make sure you support the other side so it doesn't put any pressure on the fittings when you give it a wack.

Yes that does look like Australia...Oi!Oi!Oi!


Is your barrel 40mm PVC?If it is..Give golfballs a go,you'll be delighted!Fits PN12 perfect but nto to sure about PN18.

rna_duelers wrote: Is your barrel 40mm PVC?If it is..Give golfballs a go,you'll be delighted!Fits PN12 perfect but nto to sure about PN18.

Nah 40mm PN18 is a tiny bit to small, I already played the back 9 at the local and looted the bushes at the end of the driving range for like 100 golf balls too!

Looking good, though that hole looks more like an amoeba halfway through binary fission

If I were you I'd make the hose from the trigger much much shorter, ideally you should mount the blowgun directly to the valve. This will pilot the diaphragm quicker and give you more power.

jackssmirkingrevenge wrote:If I were you I'd make the hose from the trigger much much shorter, ideally you should mount the blowgun directly to the valve. This will pilot the diaphragm quicker and give you more power.

Yeh that makes sense, I didn't think of that but I really like having the trigger on the back and if it was connected directly onto the sprinkler it wouldn't be very secure since the hole is drilled into the side which is fairly thin, because of the guide pin.

You could always shorten the pipe to and inch or so - it depends what you value most, practicality or efficiency

jackssmirkingrevenge wrote:You could always shorten the pipe to and inch or so - it depends what you value most, practicality or efficiency

Any idea how much of a difference it makes? It would be interesting, I think I would need to buy a different pipe tap, then I could test it with no hose.

I can't tell you how much feet per second you'll gain but it should be noticeable.

It is noticeable,I was using a sprinkler valve with a hose that was about...ohh 30cm long or so for one of my guns and it was very weak to shoot compared to shooting without hose,go the nose hose way if you can.

It would be interesting if someone with a modded sprinkler valve launcher firing consistent ammunition like say golfballs could do some tests with different hose lengths through a chrony to have some concrete figures on the effects of excess pilot volume.