My project

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
Right now I am making a mortar tube that shoots out small projectiles. It uses washers, springs, dowels, PVC cement, PVC tubes, a hand made wooden frame, hinges, and etc. I'll put pictures up. Its actually kinda hard. :speakcool:
 

Nerull

Addon Developer
Addon Developer
Joined
Dec 28, 2008
Messages
100
Reaction score
0
Points
0
Using PVC for anything holding pressure or experiencing shock (or worse - both at once) is a very bad idea. When it fails it turns into shrapnel. It's been mostly banned from use with compressed air for that reason.
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
Lol. I cemented the PVC cap on the back. The dowel fits through. I put a string on the dowel to pull it back and cock the launcher. The projectile is going to be fairly small so it is not that dangerous in my opinion. Anyway, after you let go of the string, the dowel flies up and hits the small projectile and launches it at multiple angles to see which one goes the farthest distance. It really isn't that bad. Like I said I'll show you pictures and diagrams.
 

Eagle

The Amazing Flying Tuna Can
Joined
Feb 11, 2008
Messages
1,109
Reaction score
3
Points
0
ABS plastics are a little more tolerant of impact than PVC fyi.

Though if you're just using a spring to propel the mortar, PVC should be just fine.

EDIT:

Oh, if the height of the exit of your tube and landing zone are the same the most efficient angle is 45 degrees (neglecting air resistance). With no air resistance angles the same displacement above and below 45 should be identical.

With air resistance, its better to aim slightly below 45. Exact physics will depend upon the ballistic coefficients of your projectile.
 

RisingFury

OBSP developer
Addon Developer
Joined
Aug 15, 2008
Messages
6,244
Reaction score
2
Points
38
Location
Among bits and Bytes...
Should be around 43°. Just aim for 45°. There are plenty of other things you can improve far better then the 2 angle :p
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
Here are some pictures......
 
Last edited:

Hielor

Defender of Truth
Donator
Beta Tester
Joined
May 30, 2008
Messages
5,632
Reaction score
0
Points
0
Here are some pictures......
Make sure you have a video camera rolling when you use the thing, so we can all watch it blow up in your face...
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
HA HA. Was that literal or a joke?
 

Bj

Addon Developer
Addon Developer
Donator
Joined
Oct 16, 2007
Messages
1,888
Reaction score
10
Points
0
Location
USA-WA
Website
www.orbiter-forum.com
I am sure quite literal.

Please if nothing else, encase the whole thing in thick wood with at least a 6"- 12" clearance.
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
What do you guys think I am launching? 30mm rounds? My most dangerious projectile is a fore cracker with an extended fuse. Those fuses are like 3 sec. With a longer one it ais good enough. But it really isn't as dangerous.
 

Bj

Addon Developer
Addon Developer
Donator
Joined
Oct 16, 2007
Messages
1,888
Reaction score
10
Points
0
Location
USA-WA
Website
www.orbiter-forum.com
What do you guys think I am launching? 30mm rounds? My most dangerious projectile is a fore cracker with an extended fuse. Those fuses are like 3 sec. With a longer one it ais good enough. But it really isn't as dangerous.

Just so you know, a kid from my HS tried to make a firework. Granted he was stupid and was getting the gunpowder from .22 shells, but he didn't discharge static electricity, and well long story short, blew off his finger, and took a chopper ride to Seattle, which cost about $10,000...

Really expensive firework, wouldn't you say?:blink:
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
Just so you know, a kid from my HS tried to make a firework. Granted he was stupid and was getting the gunpowder from .22 shells, but he didn't discharge static electricity, and well long story short, blew off his finger, and took a chopper ride to Seattle, which cost about $10,000...

Really expensive firework, wouldn't you say?:blink:
I suppose. Right now I am doing lots of school work so whenever I get to my little project I'll take safety precautions. Anyway, what do you guys think of it. Its one of my first projects.


Really expensive firework, wouldn't you say?:blink:
But if anything were to happen my dad is in the army. :p
 

Eagle

The Amazing Flying Tuna Can
Joined
Feb 11, 2008
Messages
1,109
Reaction score
3
Points
0
Cherry bomb in an open pvc pipe isn't dangerous. Now if there was a projectile holding down the cherry bomb then maybe, but when it is the projectile, no biggie.

Just don't be a complete flap and get yourself hurt.
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
I won't. I am a lot smarter than I seem. Intelligently and knowledgeably. Anyway, what is a good projectile to launch in your opinion?
 
Last edited:

RisingFury

OBSP developer
Addon Developer
Joined
Aug 15, 2008
Messages
6,244
Reaction score
2
Points
38
Location
Among bits and Bytes...
No offense... but it doesn't seem *too smart* to be downplaying the danger, knowing it's there.

I take good precautions when starting my 6.5 ccm nitro engine by hand (such as double gloves and having someone hold the plane). I know a guy who lost 3 fingers when starting a nitro engine. Doctors managed to reattach two, but only one is functional.
 

MJR

C++ developer in the mix
Addon Developer
Tutorial Publisher
Donator
Joined
Mar 19, 2008
Messages
2,468
Reaction score
5
Points
0
Location
United States
What do you mean downplaying? I am not underestimating what could happen. Thats why I got more than one person helping me with the experiment. In another post somebody said to encase it with wood. Thats what I will do when I have time. Like I said, I am doing lots of school work.
 

Sky Captain

New member
Joined
Jan 29, 2009
Messages
947
Reaction score
0
Points
0
Compared to my homebuilt 2,4 m diameter wind generator which disintegrated during the windstorm Erwin 5 years ago sending pieces of propeller blades flying all over the place at several hundred m/s this thing looks completely innocent.
Luckily it was night when my wind generator exploded so no one was outside and only property damage was broken window of neighbor`s garage. Otherwise it could have easily ended with someone seriously injured or even dead. Later I found 1 m long piece of blade that was penetrated more than half of it`s length into hard compacted ground as a testament of how violently this thing came apart.
 

RocketMan_Len

New member
Joined
Jun 22, 2008
Messages
149
Reaction score
0
Points
0
Location
Toronto, ON
My only question about this project is - WHY?

What are you hoping to accomplish, in constructing a firecracker-thrower?

I'll consider any answer except "I Think It's COOL"... :rofl:
 
Top