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View Full Version : Jonny69's inventing shed: Giant Spudmatic gun

Jonny69
28-04-2009, 20:09
On another forum I'm being pestered to put some more of my toys online so I'm going to run a series of threads and show you what I've got in my garage. I'll start with the spudmatic gun I made today and move onto some of the older stuff as my bandwidth allows :D

So, plan is to make a little reservoir out of steel tube that I can pump up with a bike pump and have a ball valve at the other end to let it all out at once. No fire, reliable and repeatable tried and tested method which I used last week on one of the gags at work, for firing a model Polaris missile.

Start with a bit of 75mm tube, this bit is 250mm long:

http://www.dropfiles.net//files/319/inventions/IMG_3814.JPG

It needs two endcaps, one with a hole in it. Cut these out with a 1mm blade in the angle grinder, then clean them up with a flap wheel. The hole is cut with a Screwfix holesaw which has lasted just 3 holes in 2mm steel:

http://www.dropfiles.net//files/319/inventions/IMG_3815.JPG

(I'm not all pro using engineers blue but the way, the steel I had happened to have it on already)

Through that hole is going a brass tank fitting, a common plumbing fitting for 15mm copper pipe:

http://www.dropfiles.net//files/319/inventions/IMG_3816.JPG

Fits through the hole like so:

http://www.dropfiles.net//files/319/inventions/IMG_3818.JPG

I've drilled a hole in the side so I can squish through a tyre valve that I got from the local tyre place:

http://www.dropfiles.net//files/319/inventions/IMG_3819.JPG

http://www.dropfiles.net//files/319/inventions/IMG_3821.JPG

This is the only difficult bit for most people, welding the ends on:

http://www.dropfiles.net//files/319/inventions/IMG_3822.JPG

The tank fitting needs to be tightened up before the end is welded on so I cranked it up paggin' tight with some PTFE inside, welded in short stitches and cooled in water each time to stop too much heat getting to the brass:

http://www.dropfiles.net//files/319/inventions/IMG_3823.JPG

It's assembled with a lever ball valve tap thing, again, another common plumbing part with compression fittings so no tapping or soldering needed:

http://www.dropfiles.net//files/319/inventions/IMG_3824.JPG

And this is how it works, fairly self explanatory:

http://www.dropfiles.net//files/319/inventions/IMG_3825.JPG

Testing.

The good news is it works pretty well. The pump is a bit rubbish but 40psi sends a 15mm slug of potato clean over the 3 stories of flats in my building. 100psi sends it right over the block adjacent and 160psi which is pretty much all I can manage with all my weight on the pump goes about 75 metres down the road with a bit of recoil.

I'm chuffed, first toy for the camping trip in June is complete. Better stock up on potatoes :D
Fayshun
28-04-2009, 20:11
AWESOME!!
Burble
28-04-2009, 20:11
I want to live next door to Mr. 69!
Belmit
28-04-2009, 20:16
I want to live next door to Mr. 69!

I don't, the lawn would just be littered with chunks of raw potato!


I think it needs to be adpated to have a superheater at the end so it makes instant chips.
Fayshun
28-04-2009, 20:23
I don't, the lawn would just be littered with chunks of raw potato!


I think it needs to be adpated to have a superheater at the end so it makes instant chips.
With a salt and vinegar dispensing "afterburner"!
Belmit
28-04-2009, 20:30
Food always tastes better when it's fired point blank into your face at 160psi.
Feek
28-04-2009, 20:35
You want to borrow my 300bar divers bottle? ;)

(300 bar = around 4300 psi!)
Belmit
28-04-2009, 20:37
It's the taste!

/chimp
Fayshun
28-04-2009, 20:56
You want to borrow my 300bar divers bottle? ;)

(300 bar = around 4300 psi!)
Sub orbital spuds anyone? ;D
Will
28-04-2009, 21:49
Cooooool! I wanna play!
Stan_Lite
28-04-2009, 22:08
You want to borrow my 300bar divers bottle? ;)

(300 bar = around 4300 psi!)

That could get a little messy :shocked:

The SWP (Safe Working Pressure) of a typical 15mm compression ball valve is around 16bar (approx 230psi). If the ball valve came from Screwfix, like the hole saw, I'd be wary of putting the 160psi through it that Jonny did.
Wryel
28-04-2009, 22:45
Sweet! I saw fit a funnel on the end and get tonking some King Edwards at the gypos.
Jonny69
29-04-2009, 08:29
That could get a little messy :shocked:

The SWP (Safe Working Pressure) of a typical 15mm compression ball valve is around 16bar (approx 230psi). If the ball valve came from Screwfix, like the hole saw, I'd be wary of putting the 160psi through it that Jonny did.
That's good to know. Is that for the ball or the compression fitting? This was from a plumbers merchant, not Screwfix.
Stan_Lite
29-04-2009, 08:37
That's good to know. Is that for the ball or the compression fitting? This was from a plumbers merchant, not Screwfix.

It wasn't clear but I would think the compression fitting would be the weak point rather than the ball.
Davey_Pitch
29-04-2009, 10:34
I wanna see it in action! Get some vids up Jonny :D
Jonny69
29-04-2009, 13:28
TAKE 6! *snap*

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/PUqNcPVZijg&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/PUqNcPVZijg&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
Burble
29-04-2009, 13:34
WANT!
Will
29-04-2009, 14:10
TAKE 6! http://www.youtube.com/v/PUqNcPVZijg&hl=en&fs=1

:D
Jonny69
29-04-2009, 14:16
I took another, crouched down leaning right back for the camera shot, but it knocked me over :D
Desmo
29-04-2009, 14:58
I'd leave the bolt in the end ::/: ;D
Happy
29-04-2009, 15:06
Awesome :D
Jhadur
29-04-2009, 15:29
Giz a go mister :D
Davey_Pitch
29-04-2009, 15:53
That's freaking awesome Jonny, I so want a go at that. Can you next do a video of yourself shooting it at some passing chavs? That would be a YouTube hit in no time :D
Darrin
29-04-2009, 18:59
Dude, some of the things you do make me wish I didn't live over here. I'd be camping out in your garage!!
Mark
29-04-2009, 20:04
Any more near misses with the Police to report? ;D
Fayshun
29-04-2009, 21:32
I'm sorry to report, J69 has been detained under the Prevention of Terrorism act.
Jonny69
30-04-2009, 10:39
I'm sorry to report, J69 has been detained under the Prevention of potatorism act.
Fixed ;)
Jonny69
17-05-2009, 15:29
Will lives round the corner and kindly agreed to shoot me in the ass :shocked:

Take 1:

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/IOg99g1xw70&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/IOg99g1xw70&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>


Take 2:

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/Q_bfnHMOLos&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Q_bfnHMOLos&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

How gay do we look? ;D
divine
17-05-2009, 15:43
If your neighbours overheard some of that conversation, lord knows what they'd have thought!
Von Smallhausen
17-05-2009, 15:44
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/Q_bfnHMOLos&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Q_bfnHMOLos&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

****ing ROFL !!!!!!!!!!!!!!!!!!!!!!!!!
Knipples
17-05-2009, 15:59
Whatever I type here will sound wrong, but I actually cant believe im sat here nearly crying with laughter watching Will shoot Jonny69 in the arse!
;D
Very very funny boys! :D
Blighter
17-05-2009, 16:03
Awesome!! BD meet @ Jonny's garage!!! xD


PS Nice North Face fleece :o
Tak
17-05-2009, 16:09
BWHAHAHAHAHA ;D
leowyatt
17-05-2009, 16:43
Awesome johnny, I worry about your aim Will ;)
Knipples
17-05-2009, 16:45
I worry that tomorrow we're gonna have pics of Jonnys bruised arse! :shocked:
Belmit
17-05-2009, 16:51
Glad to see those squats finally came in useful!

Good stuff lads! ;D
Jonny69
17-05-2009, 17:13
PS Nice North Face fleece :o
Well spotted, nice fleece ;D
Darrin
17-05-2009, 17:22
I showed this to Tina and her only (laughing her arse off) comment was, "What straight man would actually let another laughing man shoot him in the arse???" :shocked:;D:evil:
Will
17-05-2009, 17:45
That was great fun! Can't believe how powerful that thing is! :D the pumping gets hard near the end. Maybe it was slightly gay but I don't care! I could have done it topless to make it worse! LOL ;)
Kitten
17-05-2009, 17:50
It's good to see you pumping away Will :)

/downloads ;)
divine
17-05-2009, 22:05
That was great fun! Can't believe how powerful that thing is! :D the pumping gets hard near the end. Maybe it was slightly gay but I don't care! I could have done it topless to make it worse! LOL ;)

Get the baby oil out next time too, give us a real treat :happy:
Will
18-05-2009, 07:11
I'll wait for cyprus so I have a bit of a tan first ;)
Happy
20-05-2009, 10:25
Haha, awesome effort :D