Search found 25767 matches

by jackssmirkingrevenge
Mon Oct 26, 2020 6:11 am
Forum: General How-To & Discussion
Topic: JSR's workshop chronicles
Replies: 37
Views: 8398

Re: JSR's workshop chronicles

Finally some activity! https://i.imgur.com/l4lZK8w.gifv 1mm deep cut in C12L14 steel just for the purposes of testing. I found a nice little business not far away that does small quantities for a variety of materials and I made an order to start things off: https://i.imgur.com/Gtmn3sk.jpg A neatly s...
by jackssmirkingrevenge
Thu Oct 22, 2020 5:16 am
Forum: Pneumatic Cannons
Topic: Concerning video of a Piston Valve Cannon bursting
Replies: 10
Views: 218

Re: Concerning video of a Piston Valve Cannon bursting

mrfoo wrote:
Wed Oct 21, 2020 12:26 am
"fuck me, that could have taken my hands off".
In other news, it seems the swear filter has not made it to the new spudfiles!

You can say fuck, shit, bitch, whatever you want!

Cock, balls!
by jackssmirkingrevenge
Wed Oct 21, 2020 6:45 am
Forum: Pneumatic Cannons
Topic: Coaxial Piston Cannon Troubleshooting (no air pressure)
Replies: 1
Views: 87

Re: Coaxial Piston Cannon Troubleshooting (no air pressure)

Welcome to the forum, and nice 'stache. "my son" :roll: :D I think the piston is probably the issue, especially if you are using a hand pump. If it is not free to move and reasonably air tight, then air will just go past it as you are filling and go straight out the barrel. If you were filling with ...
by jackssmirkingrevenge
Wed Oct 21, 2020 6:38 am
Forum: General How-To & Discussion
Topic: Fly-K mortar - "captive piston" variation
Replies: 10
Views: 5290

Re: Fly-K mortar - "captive piston" variation

Haha very nice :) I increased the amount of air, because you need more air to decently throw the projectile. That is usually the issue with this type of setup, a lot of dead volume and small surface for the pressure to act on vis a vis the projectile diameter. Still, it looks like it would be fun!
by jackssmirkingrevenge
Wed Oct 21, 2020 6:35 am
Forum: Pneumatic Cannons
Topic: Concerning video of a Piston Valve Cannon bursting
Replies: 10
Views: 218

Re: Concerning video of a Piston Valve Cannon bursting

The break at the barrel end was clean and exactly at the stress riser where the reducer meets the valve body, looks like shock fracture rather than pressure rupture. Lesson to learn - don't do that. Agreed, all the force is on that PVC tee. If you are making an over/under piston cannon out of PVC, ...
by jackssmirkingrevenge
Wed Oct 21, 2020 6:30 am
Forum: BB, Airsoft, and Pellet Guns
Topic: vortex + polymer water beads?
Replies: 1
Views: 41

Re: vortex + polymer water beads?

Never actually handled them but in this fellow's video test you can see them bouncing off after being shot at a wall, I would say they would probably survive being put in a low pressure vortex gun.
by jackssmirkingrevenge
Sun Oct 18, 2020 10:51 am
Forum: General How-To & Discussion
Topic: shut-off valve suppressor
Replies: 81
Views: 14636

Re: shut-off valve suppressor

Contemporary article about the work of French inventor Colonel Guilbert Humbert

Image
by jackssmirkingrevenge
Sun Oct 18, 2020 9:24 am
Forum: Hybrid Cannons
Topic: Autonomous pistol .22
Replies: 13
Views: 825

Re: Autonomous pistol .22

hectmarr wrote:
Sun Oct 18, 2020 8:59 am
I tried to think like a simple rupture disk, but it lasts for many shots before changing it, and well, something very small and simple to build.
You achieved that objective admirably, no doubt about it :)
by jackssmirkingrevenge
Sun Oct 18, 2020 4:59 am
Forum: Hybrid Cannons
Topic: Autonomous pistol .22
Replies: 13
Views: 825

Re: Autonomous pistol .22

As brilliant as the "captive ball" is in terms of simplicity, I feel that there must be some significant power loss overcoming the o-ring friction, even if the ball bouncing back is not an issue. My impression is that a stepped piston will ultimately give the best performance: https://i.imgur.com/lE...
by jackssmirkingrevenge
Sat Oct 17, 2020 11:02 am
Forum: General How-To & Discussion
Topic: Fly-K mortar - "captive piston" variation
Replies: 10
Views: 5290

Re: Fly-K mortar - "captive piston" variation

Came across this prototype, looks like the principle is still being examined for hand-held weaponry: https://i.imgur.com/bQ293Qn.gifv source video https://www.ploughshareinnovations.com/technology/captive-piston-ammunition/ edit: more here: https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/a...
by jackssmirkingrevenge
Sat Oct 17, 2020 9:59 am
Forum: BB, Airsoft, and Pellet Guns
Topic: stonebow
Replies: 4
Views: 118

Re: stonebow

I havnt shot any metal/clay projectiles yet, but from what I read on other websites, the velocity doesnt drop much. I'd relate it to a big diesel truck: slow but torquey Essentially the velocity of the string is the velocity of the projectile, so you need a heavier projectile to better exploit the ...
by jackssmirkingrevenge
Sat Oct 17, 2020 5:55 am
Forum: BB, Airsoft, and Pellet Guns
Topic: stonebow
Replies: 4
Views: 118

Re: stonebow

Very clean work, kudos! Nice repurposing of the skis :D

It doesn't seem like it takes a lot of effort to cock. Have you tried something heavier than paintballs?
by jackssmirkingrevenge
Fri Oct 16, 2020 8:44 am
Forum: Pneumatic Cannons
Topic: Yet another QEV and 3/2 valve cannon
Replies: 3
Views: 301

Re: Yet another QEV and 3/2 valve cannon

I'm using a "detent" system with neodymium magnets to keep the shot in place, but this seems to be unreliable. Anyone here know of a good way to construct a magazine (or other device) to minimize double feeds and improve reliability? One idea would be to have a pressure actuated element that physic...
by jackssmirkingrevenge
Sat Oct 10, 2020 9:42 am
Forum: Hybrid Cannons
Topic: Autonomous pistol .22
Replies: 13
Views: 825

Re: Autonomous pistol .22

Then the restraint resistance is loosening little by little, very little by little, until the pressure generated can already eject the ammunition, and I make sure of two things: 1- that the weapon supports the maximum pressure, without damage , and 2- that the opening of the retention removes pract...
by jackssmirkingrevenge
Wed Oct 07, 2020 4:39 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Regulating ROF in a BBMG with constant air flow (solution)
Replies: 1
Views: 458

Re: Regulating ROF in a BBMG with constant air flow (solution)

Image doesn't seem to be working.

Here is something along similar lines I had worked on: viewtopic.php?f=29&t=23240

Feed was not very reliable on the prototype I had made but the basic idea worked: