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 83 users online :: 4 registered, 0 hidden and 79 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

Access to lathe...what should I make?

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

Access to lathe...what should I make?

Unread postAuthor: shardbearer » Thu Apr 23, 2015 6:38 pm

I haven't been on spudfiles or worked on any my cannons in over a year, but I have access to a small and underpowered Unimat 3 lathe for the next 3 weeks, and figured I should make a new cannon. First time using a lathe yesterday I tried turning some scrap material, the motor kept stalling on 1-1/2" copper but 5/16" steel machined fairly nicely.
Image
Image
I ordered some aluminum and delrin, they should be here tomorrow. I'm definitely going to make some projectiles for my 1/2" QEV gun, unfortunately it doesn't have a compound slide so I can't really do any kind of taper, and doesn't have power feed to do threads, but I'll see what I can do.

As for a new gun, I was thinking of getting my fridge compressor working and then making a high pressure 1/2" copper gun, based off the PACA MK II with a delrin QDV. Is there an easy pen gun design I can make without threading? Should I attempt to machine a replacement piston for the leaky one in my 2" golfball cannon? Any other ideas?
  • 0


shardbearer
Sergeant
Sergeant
 
Posts: 85
Joined: Sat Apr 23, 2011 10:21 pm
Reputation: 0

Re: Access to lathe...what should I make?

Unread postAuthor: Gippeto » Sat Apr 25, 2015 10:44 am

A lathe opens all sorts of doors for creativity to bloom, and it seems like you already have some ideas of your own. :)

Common round parts are valve parts and projectiles. Due to your limited time, would suggest you do the projects you already thought about, and then if time permits... hammer valve.. toolies piston...balanced or partially balanced valve...bullet mold...higher pressure stirrup pump...list could get pretty long. :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: 2394
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Re: Access to lathe...what should I make?

Unread postAuthor: shardbearer » Sat Apr 25, 2015 11:37 am

Ooh, a hammer valve and stirrup pump would be fun too... but I have so many projects :?

Here's some CAD drawings of the 1/2" copper gun I was thinking about, 24" barrel, 3/4" x 45" chamber that can be reduced to 18" if I don't want to pump as much. At 800psi, GGDT predicts ~800fps with a 1/2" ball bearing :shock: Debating whether to step the valve body up to 3/4"...

Image

No, I did not model all those copper fittings by hand. McMaster has CAD models of almost everything they sell :)Image

Valve cross section, before firing. There will be a spring behind the trigger to push it back to this position, and some felt behind the piston to cushion it.
Image

Valve actuation point
Image

Valve after firing
Image

EDIT: Shrunk the images to a reasonable size, click on one to see the high res version.
  • 0


shardbearer
Sergeant
Sergeant
 
Posts: 85
Joined: Sat Apr 23, 2011 10:21 pm
Reputation: 0

Re: Access to lathe...what should I make?

Unread postAuthor: dart guy » Sat Apr 25, 2015 2:28 pm

why not spring load the trigger? it may make it a little larger and more complicated, but it would push the valve open pretty fast helping achieve greater accuracy. also i agree with gippeto, make some bullet molds while you can. Hot glue bullets seem to be popular(also weighting the tip is possible by putting a piece of nail into the mold), But unless you rifle your barrels they will have to have a front heavy design with some rear drag.
  • 0

when life gives you lemons... make root beer and leave the world wondering how you did that :D
User avatar
dart guy
Major
Major
 
Posts: 397
Joined: Mon May 13, 2013 7:54 pm
Location: not telling you
Reputation: 5

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'