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 66 users online :: 5 registered, 0 hidden and 61 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Barrels

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: warhead052 » Sun May 13, 2012 10:21 pm

Well, if its two cylinders going into each other, you would have to rotate it until it works, if its built in and pre drilled, well no need to line it up.
  • 0


warhead052
Major General
Major General
 
Posts: 1769
Joined: Mon Mar 21, 2011 5:41 pm
Reputation: 0

Unread postAuthor: Goats spudz » Mon May 14, 2012 1:51 am

no you wouldn't you have a 15mm tube and a 15mm barrel both with the same ID of 4.5 or 5.5 mm depending on caliber, going into a 15.01 mm hole it will line up
  • 0

Where's my Chuck key?

Goats spudz
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 458
Joined: Tue Aug 02, 2011 12:31 pm
Reputation: 0

Unread postAuthor: DYI » Mon May 14, 2012 6:40 am

Goats, I think what warhead is getting at is the issue of concentricity of the bore with the tube for both tubes.

So long as the barrel's bore is sufficiently concentric with its external diameter, this is just a matter of producing the OD and ID of the other part without re-chucking, which will ensure concentricity.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: Gippeto » Mon May 14, 2012 9:27 am

Keep it simple...drill the transfer port into the barrel...or use a longish flow through bolt. This really does not have to be difficult. :)

Image
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: wyz2285 » Mon May 14, 2012 10:30 am

Flow through bolt :idea:
That solves everything :D But how does it affects the flow? I still want a muzzle speed of >1000 fps :roll:
  • 0

CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

Unread postAuthor: Gippeto » Mon May 14, 2012 11:17 am

wyz2285 wrote:I still want a muzzle speed of >1000 fps :roll:


Not for accuracy you don't. Max should be around 900fps with whatever ends up grouping best....hopefully 10.3gr. Best accuracy will likely be slower yet.
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: wyz2285 » Mon May 14, 2012 11:30 am

But won´t higher speed give a straighter trajectory? Accuracy for me comes first, but I do hope it can do some damage like penetrate a coke can at 40/50 meters :roll:
  • 0

CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

Sponsored

Sponsor
 


Unread postAuthor: DYI » Mon May 14, 2012 11:48 am

At speeds where trans-sonic effects become noticeable, accuracy will be reduced. If you want "damage", you shouldn't be firing .177 pellets with compressed air :lol:
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: wyz2285 » Mon May 14, 2012 12:01 pm

you shouldn't be firing .177 pellets with compressed air

I did took a long thought about machine about 5 cartridge and make bolt-action hybrid, but from JSR´s results, valveless isn´t reliable, burst-disc is too complicate. But indeed, I should use this opportunity to build a decent hybrid :) (but hybrid is that kind of thing that´s between firearm and hobby :? also because spudding isn´t popular around here at all, I can´t even find a law about it)
  • 0

CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

Unread postAuthor: DYI » Mon May 14, 2012 12:22 pm

Come on wyz, you should have at least included an ellipsis at the start of that quote :P

I don't have any problem with traditional pellet guns, and a hybrid gun which fills the function you're looking to achieve would be very difficult to design, and quite expensive. It's also worth noting that the pellets you want to fire are not designed for stable supersonic flight, and that the launch forces may end up destroying them, especially in a commercial barrel which has a twist rate appropriate for operation as a compressed air pneumatic.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: Goats spudz » Mon May 14, 2012 12:29 pm

IIRC the airforce condor reaches 1200+ FPS with room temperature air
  • 0

Where's my Chuck key?

Goats spudz
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 458
Joined: Tue Aug 02, 2011 12:31 pm
Reputation: 0

Unread postAuthor: wyz2285 » Mon May 14, 2012 1:30 pm

you shouldn't be firing with compressed air

True true, but time will tell, if there are any time left to design a above 50x hybrid, I´d give it a go, as have the parts machined won´t cost me a penny :D the only problem would be where to shot it.
Gippeto: What do you think about this?
  • 0

Attachments
bolt.jpg
CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

Unread postAuthor: Gippeto » Mon May 14, 2012 1:37 pm

Goats spudz wrote:IIRC the airforce condor reaches 1200+ FPS with room temperature air


Yep, the Condor can reach those speeds...and more. I've seen a much modified Condor shooting .177's chronying ~1400fps and still grouping "fair" at 25m. Was ~ 3/8" ctc as I recall. Would be real deadly close up. :twisted:

But push the range out....and it becomes a truly ineffective shotgun. :(

The owner switched to a .25 setup to make better use of the air he was using...now pesting beyond 100m.

If trajectory is your biggest issue, get chairgun. When you've settled on a pellet and velocity, you enter that data into chairgun and print yourself a handy trajectory chart...if yer real picky, get a range finder to add to your kit.

Edit: You REALLY don't want to drill that hole do ya. :lol: You really won't bugger the whole barrel if you fork up the tp hole once or twice....at worst it costs you an inch or so of length....and you won't fork it up. :wink:

That's the basic idea. The hollow section of the probe should be ~.010" smaller than the lands of the rifling...this will allow you to NOT have to chamber the barrel. (assuming you don't drill the barrel for the tp)

Obviously the barrel cannot be allowed to block the flow to the probe...the receiver block is going to need some alteration to accommodate the transfer port and the probe will need to be lengthened to compensate.

ORRRRR...you could drill the bloody hole in the barrel. :lol:
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: wyz2285 » Mon May 14, 2012 2:29 pm

Fine!, I drill the hole :) should be fine.
Also, once this gun is finished, and I feel more experienced, I would design a .22 with high muzzle speed, for now looks like I should stay around 900 fps, witch it´s good too, it will give me more shots, also much easier to open with a solenoid :)
  • 0

Last edited by wyz2285 on Wed May 30, 2012 9:52 am, edited 1 time in total.
CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

Unread postAuthor: wyz2285 » Sun May 20, 2012 7:00 am

Watched this video.
Is the bad accuracy because it was too powerful or there are something to do with the barrel :? I saw a edgun matador shooting pretty well at 100 yards with a L.W barrel :?
  • 0

CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
wyz2285
Major General
Major General
 
Posts: 2244
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Country: Portugal (pt)
Reputation: 12

PreviousNext

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'