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Posted: Fri Jun 26, 2009 7:53 pm
by spudtyrrant
i just did external ballistics in the ggdt and it says you are getting approximately 600yards at 80psi with a 16.9 ounce water bottle not bad if you ask me

edit: it should get even more than that i just put in my golfball cannon which it says has a range of 200yards when it has a measured range of 400 so even the impressive can be outdone lol
Posted: Sat Jun 27, 2009 1:26 am
by inonickname
Yet again, one beastly awesome cannon!
After looking at the patent of the parsonault, I'm not quite getting the concept. Is it 'valveless' or a balanced piston..et cetera?
Posted: Sat Aug 08, 2009 3:17 pm
by mobile chernobyl
Finally!!!
A planned shooting date of TOMORROW. If all holds together, I will be shooting a plethora of ammo which can be found on the first page, second post!
Yes, this is the FIRST time it will be shot at full power! up until now I have barely tipped the scale at 40PSI and it shoots amazingly. Tomorrow I will be shooting ammo with a lot more potential havoc on it's targets... whatever they may be.
Godspeed!
Posted: Sat Aug 08, 2009 4:53 pm
by King_TaTer
Looking forward to it mobile. I saw all the ammunition you've collected. You've been quite busy.
What are the planned targets?
Posted: Sun Aug 09, 2009 6:14 pm
by mobile chernobyl
Well the shooting went down! It was a fun day, but ended sooner than thought with a not-so-catastrophic failure of the piston's seal face. Photo's are posted on the second post of the first page, video's will be updated in a little while.
All in all - the best ammo was the canned food. All of the "fletched" ammo I made did not fly straight or attempt to at all. Perhaps better fletching or something will be needed. I also didn't park the gun right up against the target either, most everything was about 20 yards away... so in that distance the ammo had enough time to tumble. Basically I did not get any good penetration test's but I did get to finally shoot this thing at 80psi and HOLY HELL!!!! it's hard to compare it to anything as I haven't exactly shot a air cannon I would classify as "big" in around 2 years, so I had nothing to compare the power to, but it was not disappointing!
So if anyone has any input on making better penetrating ammo that is more aerodynamically stable, I'm listening! I'm absolutely certain this gun will destroy it's targets well, the only thing holding it back now is the limited ammo selection.
Posted: Sun Aug 09, 2009 7:01 pm
by c11man
thats some nice damage. while you have the piston out and repairing it you might want to consider reduing it so that its lighter. prolly not much preformance gain but i would deffenetly feel safer with les weight hitting the bumper
Posted: Sun Aug 09, 2009 7:19 pm
by AtomicJew
Rifling: For ammo stability there is only one answer.
Very cool rolling tripod mount, what max angles for firing and travel? I plan to do something similar while mounting a cylinder in the third leg but had not considered adding an elevator till now. currently I use a 4 wheel cart with wheels that dont off-road well.
Posted: Sun Aug 09, 2009 7:41 pm
by mobile chernobyl
Rifling: Not easily attainable by the average spud-gunning enthusiast lol
Thanks for the comment on the stand. It reaches a max inclination of about 35 degrees. Do you have any work yet I could check out?
Posted: Sun Aug 09, 2009 7:42 pm
by jonnyboy
Your fletching looks a little small. I would make them as big as reasonably possible, maybe a spring out design or something that unfolds so the barrel diameter doesn't matter.
@atomicjew
Dart's shouldn't need rifling

Posted: Mon Aug 10, 2009 3:30 am
by inonickname
AtomicJew wrote:Rifling: For ammo stability there is only one answer.
Nope not really. Darts, as wellas foster and skirted rounds are also very accurate.
Riflings are done easily on smaller scales, though impractical for anything this big.
Posted: Sat Aug 15, 2009 11:13 am
by D_Hall
Missed this thread until now but a couple thoughts....
1) That filing cabinet on the first page is an old government surplus cabinet from somewhere in the 40s to 60s. At the time, documents classified as "CONFIDENTIAL" were cleared for storage in such filing cabinets. In other words, they were considered "light" safes. Note that there are still a mess of those cabinets out there as they're so well made that they'll probably still be in use after I retire, but these days they're used as nothing more than simple filing cabinets and are no longer considered secure fore even mere "CONFIDENTIAL" documents.
2) As the projectile clears the muzzle all that pressurized air suddenly has an escape path and it takes it. Result? Sudden tailwind on the projectile which can destablize it. It may very well regain stability, but probably not gonna happen in the 20 yards you advertise as your range to target. Taking a longer range shot may yield better results. Alternatively, a muzzle break may help by giving much of the air a place to escape that doesn't take it across the tailfin surfaces.
edit: Oh, and while your cannon is a beauty, I had to vote "I've made bigger out of spare parts" because... Well, Vera is made primarily out of spare parts.

Posted: Sat Aug 15, 2009 12:33 pm
by ramses
D_Hall wrote:Alternatively, a muzzle break may help by giving much of the air a place to escape that doesn't take it across the tailfin surfaces.
what, like this?
for the love of god, it is a muzzle
brake...
sig heil grammar nazi!
[/offtopic]
but yeah, a muzzle brake should help substantially. and it would look badass...
Posted: Sat Aug 15, 2009 1:15 pm
by Ragnarok
Oh come on Ramses, even I wouldn't go to that length because of that.
I'll criticise for a post that looks like it's a reject from the infinite monkey room, but that response for a single spelling mistake?
That's right, you're being told you're a rude pedant by even this rude pedant's standards.
Also, the irony/hypocrisy in your post:
There are two errors in D_Hall's 188 word post ("Break" instead of "brake", and stabilize is missing an I).
There are SIX errors in your 31 word post. Six missing capital letters (5 sentence starts, and "Nazi" is a proper noun).
Three times as many errors in a sixth of the word count. There's a phrase for this, and it involves the words: "Black", "kettle" and "pot".
Posted: Sat Aug 15, 2009 3:47 pm
by Hotwired
Come on, if you're not going to PM a lecture don't post it.
Nothing can get posted on the interwebnet without someone knowing what it was it seems, not even an aged filing cabinet.
Posted: Sat Aug 15, 2009 3:59 pm
by ramses
Ragnarok wrote:Oh come on Ramses, even I wouldn't go to that length because of that
Yeah, that post took me about 15 minutes to type up. Most of the time was spent looking for a gnarly muzzle brake to use. I suppose this post was just a built up rant about people consistently using the term "muzzle break."
Ragnarok wrote:
There are SIX errors in your 31 word post. Six missing capital letters (5 sentence starts, and "Nazi" is a proper noun).
Three times as many errors in a sixth of the word count. There's a phrase for this, and it involves the words: "Black", "kettle" and "pot".
7, actually. It isn't proper to start a sentence with "and."
Oops, "7, actually" is a sentence fragment:oops:
All of my errors were an intentional attempt at irony.
on a side note, the picture of the "muzzle break" is actually the failed hybrid chamber from
this thread. I hope Pat123 doesn't mind...