Our first gun we built. It was built from a 24" x 4" combustion chamber and a 50" barrel. It does pack quite a punch. We also mounted it on a lumber frame tripod. So far we have cleared about 300yds and punched through 3/4" osb sheeting at 50ft on a hairspray accelerant.
a quick video clip of it firing:
[youtube][/youtube]
.50 cal machine gun style gun from SPUD COMMANDER
-
SPUD COMMANDER
- Private
- Posts: 6
- Joined: Mon Sep 30, 2013 5:11 am
- Been thanked: 1 time
- Attachments
-
Last edited by jrrdw on Thu Oct 17, 2013 2:25 pm, edited 1 time in total.
Reason: Fixed video.
Reason: Fixed video.
-
SPUD COMMANDER
- Private
- Posts: 6
- Joined: Mon Sep 30, 2013 5:11 am
- Been thanked: 1 time
dart guy wrote:i like this one better any thoughts of using burst disks?
Im new at a lot of this. Please tell me about "burst disks"?
Now you have my attention!
burst disks are things that hold pressure until you reach over the max psi. look around and you could be shooting across the field in no time.
when life gives you lemons... make root beer and leave the world wondering how you did that 
-
SPUD COMMANDER
- Private
- Posts: 6
- Joined: Mon Sep 30, 2013 5:11 am
- Been thanked: 1 time
we have already accomplished "across the field" without burst disks. Further would be nice.dart guy wrote:burst disks are things that hold pressure until you reach over the max psi. look around and you could be shooting across the field in no time.
-
MrCrowley
- Moderator
- Posts: 10078
- Joined: Fri Jun 23, 2006 10:42 pm
- Location: Auckland, New Zealand
- Been thanked: 3 times
Dart Guy, if you didn't know what burst disks are, or were too lazy to bother explaining them properly, why mention them?dart guy wrote:burst disks are things that hold pressure until you reach over the max psi. look around and you could be shooting across the field in no time.
SPUD COMMANDER,
That's a nice cannon you got there, I like the 50cal look. That tripod stand is pretty awesome too.
A burst disk is simply a piece of material that blocks the barrel from the chamber until peak combustion pressure is reached and the material bursts. A burst disk 'valve' is often very simple and offers great performance (nearly 100% flow and an opening time unmatched by other valves). In a combustion cannon like this, a burst disk can simply be a layer or two of masking tape across the breach, where you thread the barrel in to the chamber.
This minor addition can increase performance noticeably as it prevents the projectile from accelerating down the barrel until the material has burst. This means peak combustion pressure can increase since the chamber volume isn't expanding. There are a few cannons in the showcase that illustrate this design, starman's cannons are a great place to start:
http://www.spudfiles.com/forums/mr-morp ... 20185.html
http://www.spudfiles.com/forums/triple- ... 15211.html
MrCrowley. Maybe this dart guy talks all time, but his fully unexplained thing about these burst disks gave me new knowledge... I had no idea that there were these bust disks and now I doonly because of him putting it out here! And thank you about all this info about burst disks MrCrowley!
How much difference did the burst disks make for this cannon?GeoNet wrote:only because of him putting it out here!
Oh and nice cannon, looks like fun.
[center]My wife upon seeing my latest hybrid and hearing an explanation of it:
"That really isn't a potato cannon anymore, is it?"[/center]
"That really isn't a potato cannon anymore, is it?"[/center]