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 71 users online :: 6 registered, 0 hidden and 65 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

"In the world of spuds today"

A place to ask general spud cannon related questions.
Sponsored 
  • Author
    Message

Unread postAuthor: Gippeto » Sat Oct 27, 2012 9:43 pm

Very nice. 8)

Bought myself a little something as well. :)

Converted to .25 cal about 15 minutes after it arrived. :wink:

I think I need a new red dot too. :lol:

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: jackssmirkingrevenge » Sun Oct 28, 2012 1:00 am

Labtecpower wrote:Not bad for a 160€ gun I think, shooting 10 mm groups at 10 meter now, if I was a better shooter it'd be hole in hole :)


Nice, bet there are machined mods on the horizon ;)

Gippeto wrote:Bought myself a little something as well.


mmmm... this one? http://www.airgunsofarizona.com/blog/20 ... lecto.html

Pretty!

Crying out for a nice suppressor ;) What slug weight and how fast in 0.25"?
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Sun Oct 28, 2012 7:01 am

Nice, bet there are machined mods on the horizon :wink:


Yep, I want a handle like the one I made for Jake, and I certainly want to give the gas ram a try, spring twang sound cheapy hehe

First change on the gun has been made;

Image

Found this ring behind the seal between the barrel and piston chamber, has a 2mm hole in it, so it chokes the flow tremendously.. and if I find something I don't like it gets pulled out :D
Next to it is a JSB exact 4.52 for comparison :roll:
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Sun Oct 28, 2012 7:18 am

Careful, the black art that is mastery of the springer airgun implies that a bigger transfer port does not necessary mean more power.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Sun Oct 28, 2012 8:56 am

I can't see the logic behind this black art...
The groups have gotten smaller since I took out this ring, it seems to have less vibrations..

Maybe i'll just put it back in for more testing
:roll:
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jrrdw » Sun Oct 28, 2012 10:08 am

Experiment with port sizes. Make several copies with different size ports...mite be fun.
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: Gippeto » Sun Oct 28, 2012 10:53 am

Transfer port size in a springer can have a major effect on compression heating...hot gases flow faster...yes? Too little compression will also have the piston slamming into the end of the cylinder...not so good.

Jack... No suppressors here...suppressor= prohibited device = jail time.

A trade off I'm willing to make for an easily available firearms license (PAL). :)

Alecto...yes. :)

After "tweaking" the pressure relief valve, JSB Kings (25.4grain) @ 450 fps...20.5's would likely be getting ~470fps or so, which is getting close to the legal limit here which separates an "air pistol" from a "pistol"...which requires a license I don't have (RPAL) and adds restrictions to storage/transport/usage that take most of the fun out of an air pistol.

Should be plenty of snap for spring time "whack a mole". :wink:
  • 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

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Sun Oct 28, 2012 12:24 pm

Gippeto wrote:Transfer port size in a springer can have a major effect on compression heating...hot gases flow faster...yes? Too little compression will also have the piston slamming into the end of the cylinder...not so good.


That's the gist of it, not something I would play with that much.

Jack... No suppressors here...suppressor= prohibited device = jail time.


I know, just putting it as a hypothetical. I bet it's not too loud in any case though :)

After "tweaking" the pressure relief valve


I read that as "jamming in place" :D

JSB Kings (25.4grain) @ 450 fps...20.5's would likely be getting ~470fps or so, which is getting close to the legal limit here which separates an "air pistol" from a "pistol"...which requires a license I don't have (RPAL) and adds restrictions to storage/transport/usage that take most of the fun out of an air pistol.


Very decent for an air pistol, that's just under the legal limit for air rifles in the UK!

Reminds me of the Quackenbush efforts: http://www.quackenbushairguns.com/shot_pistol.html
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Sun Oct 28, 2012 1:04 pm

That's the gist of it, not something I would play with that much.


popped it back in place, needs more research before I make any changes :roll:
I still think it's too small, a lot of other guns have a hole about a mm bigger..
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Sun Oct 28, 2012 1:12 pm

Labtecpower wrote:I still think it's too small, a lot of other guns have a hole about a mm bigger..


... but they have different piston diameters and strokes, spring strengths etc.

As jrrdw suggested:

Experiment with port sizes. Make several copies with different size ports...mite be fun.


Grab a chrony and do some science!

Image

Random footnote, wyz - come come you never mentioned this?
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Sun Oct 28, 2012 1:33 pm

... but they have different piston diameters and strokes, spring strengths etc.

As jrrdw suggested:


True, I shouldn't apply the figures of other guns to mine :roll:

Grab a chrony and do some science!


I hope I can find someone near me who has one, I don't have the money to buy a chrony for testing purposes :D
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Sun Oct 28, 2012 2:43 pm

Labtecpower wrote:I hope I can find someone near me who has one, I don't have the money to buy a chrony for testing purposes :D


Could be something a bit more rudimentary since you're mainly interested in relative data as opposed to actual fps values. For example water filled beer cans in a row, count how many each variation penetrates.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: jrrdw » Sun Oct 28, 2012 2:52 pm

Labtecpower wrote:but they have different piston diameters and strokes, spring strengths etc.


Don't let that stop you, so much as .05mm might make a outstanding differance. You never know, if you have the means and time etc...
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: Labtecpower » Sun Oct 28, 2012 2:57 pm

I'm going to take a look at work tomorrow, if i'm lucky they have very thin 14 mm rings somewhere :P

I have very little time on my hands, but that isn't enough to stop me from having fun hehe

1000!!
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Sun Oct 28, 2012 3:07 pm

Labtecpower wrote:I'm going to take a look at work tomorrow, if i'm lucky they have very thin 14 mm rings somewhere :P


... and plenty of empty beer cans :D

1000!!


pfffft...

:D :D :D
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

PreviousNext

Return to General Spud Cannon Related

Who is online

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

Reputation System ©'