SpudFiles

After my friend Zach introduced me to the magical world of spud guns I immediately drafted up some designs. After he reviewed them we decided to build a base platform to the basic specifications and add all the complex luxuries later.

Here is a picture of it so far:
<a href="" title="IMG_0161 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2463/381 ... f21b2d.jpg" width="500" height="375" alt="IMG_0161"></a>

The current specifications:

• 4" x 22" chamber painted military green with yellow lettering
  MAPP Fuel @ 55 psi
  Regulated 2 valve fuel line with a 16" meter and braided steel hose
  MAPP gas holder constructed out of some 3" pvc with a hard drive magnet in the bottom mounted to the chamber with hose clamps.
  Torque bolt through the end cap to easily remove it even if it is threaded on tightly
  Taser style grill ignition with 2 spark points in the chamber
  80mm PC case fan to stir up gas in the chamber controlled with a slap switch
  All electrical components housed in a project box which is mounted flush with the chamber

The current barrel is a 1.5" x 5' with cutting edge on the chamber side. This is only temporary.

Our finished design is attached below:
<a href="" title="spud_ext_mockup by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2501/381 ... ecaa99.jpg" width="500" height="100" alt="spud_ext_mockup"></a>

As you can see we have a lot to do yet. none of it is to scale obviously but it is more so a goal mock up. It will be shoulder fired with a slap in end cap. The loading will be done with precut slugs into a hole in the barrel just above the chamber that will have a sealed sliding cover. But this design may be scrapped for now and used on another cannon since I'm debating on just attaching two bracing handles to the chamber and adding a nicer end cap handle.

Let me know what you think I should decide to just finish this up simply and start work on making that design a reality on another gun or continue to expand until we reach our initial goal.

Anyway the performance on this base line is phenomenal. First test firing was a success. We've taken it out for a couple days for hours on end and never had a miss-fire or any kind of problem. After marking a bunch of shots and measuring the distance we have an average of well over half a mile.

The build bore an unexpected fruit. Our initial design on the fuel line was to have a gas atomizer neck cut down and threaded with a 1/4" die. This proved impossible since we didn't have the necessary die for the job so we threw caution to the wind and viced down the neck and with a wrench applied torque at the valve. Unexpectidly the neck's glue gave way and allowed it to thread out and we found that there were 1/8" threads inside! Here's a few pictures of that:
<a href="" title="IMG_0128 by andrew.bachman, on Flickr"><img src="http://farm4.static.flickr.com/3555/381 ... 5e3b5d.jpg" width="500" height="375" alt="IMG_0128"></a>
<a href="" title="IMG_0127 by andrew.bachman, on Flickr"><img src="http://farm4.static.flickr.com/3582/381 ... 90b4a6.jpg" width="375" height="500" alt="IMG_0127"></a>
<a href="" title="IMG_0129 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2553/381 ... 322ccb.jpg" width="375" height="500" alt="IMG_0129"></a>

I hope this helps a few people out, I know it changed the way Zach did things as well as the rest of our local spud gun enthusiasts after they found out.

Enough of me blabbering on about this thing enjoy some finished product pictures!
<a href="" title="IMG_0133 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2472/381 ... b6dd97.jpg" width="375" height="500" alt="IMG_0133"></a>
<a href="" title="IMG_0132 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2497/381 ... 4b8e28.jpg" width="375" height="500" alt="IMG_0132"></a>
<a href="" title="IMG_0135 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2436/381 ... 2edd14.jpg" width="375" height="500" alt="IMG_0135"></a>
<a href="" title="5560_1098355066938_1468470144_30271343_4510421_n by andrew.bachman, on Flickr"><img src="http://farm4.static.flickr.com/3420/381 ... 51723c.jpg" width="500" height="375" alt="5560_1098355066938_1468470144_30271343_4510421_n"></a>
<a href="" title="IMG_0060-1 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2613/381 ... ddf00b.jpg" width="372" height="500" alt="IMG_0060-1"></a>
<a href="" title="IMG_0067-1 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2609/381 ... 3e67d3.jpg" width="500" height="375" alt="IMG_0067-1"></a>
That last picture is of me holding it with Zach's 1.5" x ~2' "Stubby Barrel".

Here is a night time video of Zach & I firing our cannons. I'm on the right with the hater, he is on the left with his baby.
[youtube][/youtube]

Some aftermath shots, first up a root beer can shot with Zach's 1.5" x ~2' "stubby" barrel with a spud at a distance of about 20 feet:
<a href="" title="IMG_0073 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2560/381 ... 782f06.jpg" width="500" height="375" alt="IMG_0073"></a>

And the aftermath of an apple tree trunk shot with my 1.5" x 5' with a spud at a distance of about 30 feet:
<a href="" title="IMG_0059 by andrew.bachman, on Flickr"><img src="http://farm3.static.flickr.com/2603/381 ... d6583b.jpg" width="375" height="500" alt="IMG_0059"></a>

If you want to see all the pictures of it's construction and more check out my flickr set on it!
All of the Photos @ flickr

Oh and one last thing, our total time of construction was 37 hours. That includes all the time taken to gather the parts, drive, build, 5 hour power nap, let the PVC glue set, finish up, and test fire. I still can't believe we pulled it off and that it fired perfectly the first time.

An average of over a half a mile? Just to let you know, a half a mile is 2,640 ft, or 880 yards. I'm not saying you didn't shoot it that far, but it seems a little far-fetched and unrealistic for a standard propane injected gun. My propane gun is almost exactly like yours and the farthest shot I will ever see is around 250-300 yards. Once again I'm not saying you didn't, but I would have to see it to believe it.

Well we were using somewhat frozen potatoes and MAPP gas. I say this is an average all shot from roughly 45 degrees. The measuring was done with a GPS. With usual ambient temp spuds they landed considerably shorter. But the confirmation was done after launching one into the embankment of a river that is just short of a half mile wide while were standing about 100 yards back in the yard.

Thats pretty "sick". I like it. I like the green and the size of the whole beast.

Moonbogg wrote:Thats pretty "sick". I like it. I like the green and the size of the whole beast.

Thank ya 8)

adrak wrote:Well we were using somewhat frozen potatoes and MAPP gas. I say this is an average all shot from roughly 45 degrees. The measuring was done with a GPS. With usual ambient temp spuds they landed considerably shorter. But the confirmation was done after launching one into the embankment of a river that is just short of a half mile wide while were standing about 100 yards back in the yard.

I think you'll find that exceptional range claims on this forum are equivalent to "I once caught a fish and it was this big!" reports elsewhere

Either way, very neat job and a good example of what advanced combustions should look like, good stuff

jackssmirkingrevenge wrote:I think you'll find that exceptional range claims on this forum are equivalent to "I once caught a fish and it was this big!" reports elsewhere

Either way, very neat job and a good example of what advanced combustions should look like, good stuff

Hahahahaha I know what you mean. The area we were launching them was a region in south central PA along the Susquehanna river, throw washington boro pa in google maps and you'll find the river. 8)

Thanks for the feedback on the cannon I'm glad my first attempt at this wasn't a failure

adrak wrote:Thanks for the feedback on the cannon I'm glad my first attempt at this wasn't a failure

Believe me, after all the duct tape wrapped ghettoness one sees on this forum, it's a relief to see that some people are still capable of doing it right first time around

jackssmirkingrevenge wrote:

adrak wrote:Thanks for the feedback on the cannon I'm glad my first attempt at this wasn't a failure

Believe me, after all the duct tape wrapped ghettoness one sees on this forum, it's a relief to see that some people are still capable of doing it right first time around

Yeah I still think I rushed a lot, I wanted to do an etched PCB board for my spark strip but ended up just bending the bolts that would have held them down for the gap and the fan isn't firmly seated but that is a temp fan until I get this one in from newegg. But I'm so glad it all just works I'm thinking for my next one using some of the 6" pressure rated PVC we found in a local hardware store while buying the hose for this

adrak wrote:

jackssmirkingrevenge wrote:

adrak wrote:Thanks for the feedback on the cannon I'm glad my first attempt at this wasn't a failure

Believe me, after all the duct tape wrapped ghettoness one sees on this forum, it's a relief to see that some people are still capable of doing it right first time around

Yeah I still think I rushed a lot, I wanted to do an etched PCB board for my spark strip but ended up just bending the bolts that would have held them down for the gap and the fan isn't firmly seated but that is a temp fan until I get this one in from newegg. But I'm so glad it all just works I'm thinking for my next one using some of the 6" pressure rated PVC we found in a local hardware store while buying the hose for this

Vantec Tornado FTW! I use them and love them. They mix gasses instantly and vent chambers in a couple seconds flat. Plus its great to have a bigass fan in your beast of a cannon.

Nice cannon, well built. Considering building my own one now, why not ya know

The distance seems sketchy to me, i've maxed out 2" housed piston valved launchers with 1.5" x 5' barrels launching golf balls and frozen potatoes at about 450m at over 120 PSI. That's about 1500 feet or about 490 yards. Using HGDT with this cannon's specifications, I get a distance of over 1100 feet, can't seem to do anything that's not drastic to get it to go above 1500 feet, let alone 2600 feet.

Sure piston valves have less flow and 'open' slower, but i'm using more pressure and potatoes aren't exactly the most aerodynamic projectile and it's not like you're a few hundred feet off, this is about 1500 feet.
BTW, you can download HGDT from here:
http://thehalls-in-bfe.com/HGDT/

I just don't see this cannon shooting that distance without some special dart as a projectile, sorry.

Believe if you want to or not, I've shot it and seen the results 8)

Thank you McCrowley for agreeing with me. Oh and by the way adrak if you had an AVERAGE of well over a half a mile, that means you had shots possibly well under 1/2 mile, and also shots WAY over 1/2 mile. There's just no way man. Your cannon looks good though.

Are you using a burst disc??? with just a tater, how are you not launching with 55psi of MAPP???

jeepkahn wrote:Are you using a burst disc??? with just a tater, how are you not launching with 55psi of MAPP???

I haven't yet but I'll give it a shot