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by jackssmirkingrevenge
Wed Jan 25, 2023 11:56 am
Forum: Hybrid Cannons
Topic: Is there a more active website than this?
Replies: 8
Views: 854

Re: Is there a more active website than this?

Not sure if the world also just got a bit more PC or woke or whatever they call it now. Given all of the bad gun related news, wielding plumbing fittings for unintended purposes can label you as a bit of a, character. I think it was always like that, on the other hand it's true that society seems t...
by jackssmirkingrevenge
Wed Jan 25, 2023 11:44 am
Forum: Miniature Guns
Topic: Dual Camera System to enhance combustion weapons.
Replies: 15
Views: 12033

Re: Dual Camera System to enhance combustion weapons.

Technically if you've divided a chamber, you now have two chambers.
by jackssmirkingrevenge
Wed Jan 25, 2023 11:38 am
Forum: Miniature Guns
Topic: Compact Semiauto Spud Gun
Replies: 4
Views: 305

Re: Compact Semiauto Spud Gun

You might want to check out this launcher and other posts by user Rambo who did quite a few experiment with this sort of system: https://www.spudfiles.com/download/file.php?id=564&mode=view In this case he was actually using the alcohol reservoir as the firing chamber, the premise being that only th...
by jackssmirkingrevenge
Sat Jan 21, 2023 4:53 pm
Forum: Hybrid Cannons
Topic: The needle valve actually failed at 150×
Replies: 3
Views: 174

Re: The needle valve actually failed at 150×

the maximum working pressure of my needle valve reaches 400mpa
Ah, but what's the maximum working temperature?
by jackssmirkingrevenge
Fri Jan 20, 2023 1:55 pm
Forum: Miniature Guns
Topic: Compact Semiauto Spud Gun
Replies: 4
Views: 305

Re: Compact Semiauto Spud Gun

I don't have any experience with launchers using alcohol vapor but they seem to work well enough and I suppose it will generate enough pressure to work a simple direct blowback bolt as drawn. What's less clear is how you intend to get an ideal fuel/air mix in the combustion chamber, and of course it...
by jackssmirkingrevenge
Wed Jan 18, 2023 10:25 am
Forum: Pneumatic Cannons
Topic: 2 position 3 way solenoid valve problems
Replies: 5
Views: 337

Re: 2 position 3 way solenoid valve problems

The solenoid you're using probably has very low flow and not dumping the QEV pilot volume effectively.

One possible solution is to add a second QEV, use the solenoid to pilot this QEV which then pilots your main QEV.
by jackssmirkingrevenge
Wed Jan 18, 2023 9:55 am
Forum: Pneumatic Cannons
Topic: preloaded pneumatic cartridge
Replies: 337
Views: 105285

Re: preloaded pneumatic cartridge

Using the cut capsule did you fill it with something or leave it hollow? Hollow suggests dead space maybe? This is a factor, to maximize performance some sort of sabot to seal it off should help and it would be an interesting thing to compare. Too much machining for me... remember the good old days...
by jackssmirkingrevenge
Wed Jan 18, 2023 9:40 am
Forum: Pneumatic Cannons
Topic: fl(air) gun - mechanically locked pneumatic cartridge for a 26.5mm flare gun
Replies: 2
Views: 207

fl(air) gun - mechanically locked pneumatic cartridge for a 26.5mm flare gun

I thought this deserved a separate thread from the earlier development . https://i.imgur.com/ZP5B0Ep.jpg Cartridge with a Polish flare gun from the 1950s based on the Soviet SPSh-44 . https://i.imgur.com/cdt0G9u.jpg Cartridge disassembled, most parts are machined from 12L14 steel apart from the body...
by jackssmirkingrevenge
Sun Jan 15, 2023 5:15 pm
Forum: Pneumatic Cannons
Topic: 2 position 3 way solenoid valve problems
Replies: 5
Views: 337

Re: 2 position 3 way solenoid valve problems

Welcome to the forum! Assuming you have a two position three ported valve, the ports should be as follows: P - inlet A - outlet R - exhaust Depending on whether the valve is normally closed or normally open, gas can flow from P to A when not energized and from A to R when energized, or vice versa. F...
by jackssmirkingrevenge
Sat Jan 14, 2023 10:31 am
Forum: Pneumatic Cannons
Topic: preloaded pneumatic cartridge
Replies: 337
Views: 105285

Re: preloaded pneumatic cartridge

An empty CO2 capsule averages at around 30 grams, so muzzle energy for those first tests at 2500 psi was in the 45 ft lbs range. In the interest of ramping things up further, I "made" a better projectile by cutting down a 12g capsule to an inch in length, now weighing in at 10 grams: https://i.imgur...
by jackssmirkingrevenge
Thu Jan 12, 2023 10:00 pm
Forum: Pneumatic Cannons
Topic: preloaded pneumatic cartridge
Replies: 337
Views: 105285

Re: preloaded pneumatic cartridge

A bit of fun using empty 12 gram CO2 cartridges as projectiles, not exactly hurtling at just over 200 feet per second but they pack quite a punch :D

by jackssmirkingrevenge
Thu Jan 12, 2023 12:22 pm
Forum: Hybrid Cannons
Topic: How do you install bursting discs?
Replies: 2
Views: 434

Re: How do you install bursting discs?

What I've always done is sandwich the disc with a o-ring between threaded fittings, this is from my mini hybrid:

Image
by jackssmirkingrevenge
Thu Jan 12, 2023 11:47 am
Forum: Hybrid Cannons
Topic: Help for spark plug leakage problem
Replies: 6
Views: 361

Re: Help for spark plug leakage problem

yyt wrote:
Wed Jan 11, 2023 9:51 pm
Do you think a self-made epoxy spark plug can work better?
I would make something like that:
Untitled.jpg
Untitled.jpg (36.17 KiB) Viewed 291 times
Using this sort of fitting:
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Untitled.jpg (22.05 KiB) Viewed 291 times
Yellow is a plastic cup or similar insulator, glue to the fitting, stick your electrode through then pour marine epoxy.
by jackssmirkingrevenge
Wed Jan 11, 2023 2:24 am
Forum: Pneumatic Cannons
Topic: preloaded pneumatic cartridge
Replies: 337
Views: 105285

Re: preloaded pneumatic cartridge

Just a little preview of a cartridge I made to fit a 26.5mm flare gun, here is a rather loud first test with air only at 2500 psi: https://youtu.be/8jp6Ljt730Y (the noise you can hear at the end is the thousands of shattered pieces of cup flying around) Here is the mechanism approximately to scale, ...
by jackssmirkingrevenge
Wed Jan 11, 2023 2:16 am
Forum: Off-Topic Hobbies
Topic: Merry Christmas
Replies: 3
Views: 484

Re: Merry Christmas

As quiet as it is in this corner of the internet these days, I hope everyone's had a good start to 2023!