Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 51 users online :: 4 registered, 0 hidden and 47 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Dart ammo for HIGH powered gun

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

Unread postAuthor: Ragnarok » Thu May 14, 2009 9:24 am

jackssmirkingrevenge wrote:PCPs that go supersonic like the Airforce Condor do so with 3000 psi on tap.

Indeed. Even then, you're more likely to find that a supersonic airgun uses a spring piston, which heats the air with rapid compression, and therefore vastly changes the speed of sound in the propellant gas, making it possible to go supersonic (in the atmosphere).
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: MRR » Thu May 14, 2009 10:55 am

I was wondering if the stability of a nail dart would be improved by using one of these ...

Image

The shape of these screw anchors look pretty promising to me.
I don't know in which sizes they are available but I think I'm going to try it at the weekend.
  • 0


MRR
Major
Major
 
Posts: 362
Joined: Tue Feb 17, 2009 2:29 pm
Reputation: 0

Unread postAuthor: psycix » Thu May 14, 2009 11:12 am

You still need to add a tail to the thing. If it just looks pointy, this doesnt mean its stabilized.
Wrap a string around the end or file into the widened part at the rear, making fins.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: thedeathofall » Thu May 14, 2009 1:41 pm

actually, that may work. The twist in the anchor will give the dart an arrow affect. It will spiral making it more accurate, and stablize it at the same time.
  • 0

"I'm spending time without a gender for tax reasons. It's great if I get hit in the groin, but a total nightmare in the bathroom."

-Rag


Obsequium parit amicos; veritas parit odium.

-Cicero

thedeathofall
2nd Lieutenant
2nd Lieutenant
 
Posts: 213
Joined: Tue May 06, 2008 10:43 pm
Reputation: 0

Unread postAuthor: Moonbogg » Thu May 14, 2009 2:14 pm

I saw THIS and realized it worked just like s spring piston air rifle. Do you think this would have any benefit over a regular pneumatic spud gun if the air was driven by a piston like this? I saw this being mentioned here in the thread and figured i'd show this. It might make a fun new cannon.
  • 0

User avatar
Moonbogg
Major General
Major General
 
Posts: 1375
Joined: Mon Oct 13, 2008 10:20 pm
Location: whittier, CA USA
Reputation: 0

Unread postAuthor: Ragnarok » Thu May 14, 2009 2:23 pm

Moonbogg wrote:I saw THIS and realized it worked just like s spring piston air rifle.

Not in the slightest! That's propane powered!
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: Moonbogg » Thu May 14, 2009 3:10 pm

Ragnarok wrote:
Moonbogg wrote:I saw THIS and realized it worked just like s spring piston air rifle.

Not in the slightest! That's propane powered!


Yeah but it slams a piston to compress air. The point is that its using a piston to compress air. So do you think it would work well for a cannon? Imagine a hybrid that uses the combustion to slam a piston forward. I can't figure out if there would be a benefit beyond using just the hybrid force alone or compressed air alone.
  • 0

User avatar
Moonbogg
Major General
Major General
 
Posts: 1375
Joined: Mon Oct 13, 2008 10:20 pm
Location: whittier, CA USA
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: Hotwired » Thu May 14, 2009 3:15 pm

Actually it doesn't.

The hand pumped piston has a reed valve (some kind of flappy valve anyway) which merely sweeps through the chamber, and pumps out the exhaust gases and at the same time allows fresh air plus a dose of propane in from the other side.


Edit: faster but worse spelling :P
  • 0

Last edited by Hotwired on Thu May 14, 2009 3:18 pm, edited 1 time in total.
User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: Ragnarok » Thu May 14, 2009 3:15 pm

Moonbogg wrote:Yeah but it slams a piston to compress air.

No, the piston is for venting the combusted gases. It plays no part in the actual firing process, and only comes into play in the reloading process.

EDIT: Darn, beaten by Hotwired by a few seconds.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: Moonbogg » Thu May 14, 2009 3:29 pm

oh. That sucks. But anyway, do you think it would be a good idea for a cannon!?
  • 0

User avatar
Moonbogg
Major General
Major General
 
Posts: 1375
Joined: Mon Oct 13, 2008 10:20 pm
Location: whittier, CA USA
Reputation: 0

Unread postAuthor: Biopyro » Thu May 14, 2009 3:40 pm

I always thought about using a piston for venting a chamber, but thought it would be impractical, because you'd need a large piston (expensive if fireproof), a check valve, and unless all the meter input, vent valve, and electronics were on the front ( the front of the reducer) it'd be impractical because you'd need to keep the chamber ID smooth. There's probably a way around it, because I hadn't thought into it much.


Also it'd be inferior to a chamber fan for mixing.
  • 0

Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. -Benjamin Franklin
User avatar
Biopyro
Colonel
Colonel
 
Posts: 656
Joined: Fri Aug 04, 2006 5:32 am
Location: UK
Reputation: 0

Unread postAuthor: c11man » Thu May 14, 2009 8:36 pm

thanks for all the imput! i dug through a old science kit and found a balence scale. the weight of a unmodded nail that i will use is slighty over 7grams. after about 10minutes of filling down the same nail on a drill press i got a nail down to 4.5 grams while increasing the preformace of it. i have a very shallow tip that takes about 3/4in to get back to normal diameter witch is very sharp. I also filed amost all of the nail head off and tapered the back end slighty so that more of the weight was in the front of it. i also gave it some groves in the back so that the glue that will hold the tail of yarn on will stick better. i also want to harden the nail so i can penetrate things harder that wood.
do any of you have ways to harden a nail? i do have access to a torch and a propane torch thing.

in ggdt i put in a 5 gram projectile (added a little weight for the tail) and it said 1415fps. should i still expect lower than mach 1? or will this insanely light projectlile shoot faster than mach 1?
  • 0

User avatar
c11man
Brigadier General
Brigadier General
 
Posts: 783
Joined: Fri Feb 06, 2009 4:37 pm
Location: Wisconsin, USA
Country: United States (us)
Reputation: 0

Unread postAuthor: THUNDERLORD » Thu May 14, 2009 9:15 pm

six words: Piano wire wire nut super glue :) 8)
  • 0

-----SPEED,STRENGTH, AND ACCURACY.-----
"Procrastination" is five syllables for "Sloth".
Theopia 8)
Born To Be Alive!

THUNDERLORD
Major General
Major General
 
Posts: 1264
Joined: Fri Mar 28, 2008 1:42 pm
Reputation: 0

Unread postAuthor: c11man » Thu May 14, 2009 9:47 pm

i was kind of hoping for a larger diameter dart....

anyway i dont understand what piano wire is or what a wire nut is. could someone explain? pics always help!
  • 0

User avatar
c11man
Brigadier General
Brigadier General
 
Posts: 783
Joined: Fri Feb 06, 2009 4:37 pm
Location: Wisconsin, USA
Country: United States (us)
Reputation: 0

Unread postAuthor: THUNDERLORD » Thu May 14, 2009 10:02 pm

c11man wrote:i was kind of hoping for a larger diameter dart....

anyway i dont understand what piano wire is or what a wire nut is. could someone explain? pics always help!


Piano wire goes up to the diameter as a giant blow gun dart.
It's hard like spring steel (available in hobby shops), so coat-hanger metal is a joke comparitively.

A wire nut is the plastic thing used to splice electrical wires (quite common).
The red "Buchanon" brand for example are about .68 diameter.
A blast of orange ones (smaller)(or yellow, orange, whatever) should probably fly straight from whatever bore. 8)
  • 0

-----SPEED,STRENGTH, AND ACCURACY.-----
"Procrastination" is five syllables for "Sloth".
Theopia 8)
Born To Be Alive!

THUNDERLORD
Major General
Major General
 
Posts: 1264
Joined: Fri Mar 28, 2008 1:42 pm
Reputation: 0

PreviousNext

Return to Construction Materials/Ammo Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'