Search found 218 matches

by mrfoo
Thu Jun 17, 2021 5:40 am
Forum: Combustion Cannons
Topic: Trouble with oxy/acetylene mix
Replies: 6
Views: 90

Re: Trouble with oxy/acetylene mix

No idea how to resolve the problem. Just posting to say "Whoah what the fuck you're clearly my kind of absolute fucking maniac" 🤘
by mrfoo
Tue May 25, 2021 12:06 am
Forum: Off-Topic Hobbies
Topic: Two Italian WW2 helmets found
Replies: 5
Views: 384

Re: Two Italian WW2 helmets found

That's pretty cool.
by mrfoo
Thu Apr 22, 2021 2:15 pm
Forum: Hybrid Cannons
Topic: Xtreme-patator
Replies: 11
Views: 746

Re: Xtreme-patator

Nice. Comme dit hector, le cuivre ne risque pas d'aimer cette utilisation. Tube acier sans soudure Ø20, ep2 te donnera Øint de 16mm, ce n'est pas trop cher - https://lamtechno.com/tube-acier-de-precision-e235n-rond-sans-soudure-cintrable/90-381-tube-acier-sans-soudure-cintrable-diametre-20.html#/23-...
by mrfoo
Thu Apr 01, 2021 12:26 am
Forum: Pneumatic Cannons
Topic: Pressure rating for Coaxial cannons
Replies: 12
Views: 1195

Re: Pressure rating for Coaxial cannons

Good question. The force being applied to the barrel will be compression, rather than tensile, and PVC (like many materials) is stronger in that respect. Tensile strength of rigid PVC, 34 … 62 MPa, Compressive strength 55 … 89. So in that respect, you're probably OK. However. These figures are signi...
by mrfoo
Sun Mar 28, 2021 6:23 am
Forum: Hybrid Cannons
Topic: Large hybrid
Replies: 10
Views: 1125

Re: Large hybrid

Norguns wrote:
Sat Mar 27, 2021 11:56 am
I get what you are saying, I might not get any real velocity gain from it. That being said, the entry fee for evacuating the air from the barrel is low on my setup and i might play with it at a later time.
You owe it to yourself to try :)
by mrfoo
Tue Mar 16, 2021 1:12 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Spring powered Nerf blaster
Replies: 9
Views: 998

Re: Spring powered Nerf blaster

Outstanding!
by mrfoo
Tue Mar 02, 2021 12:30 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Spring powered Nerf pistol
Replies: 7
Views: 743

Re: Spring powered Nerf pistol

Back in the day, we used to do that to bike parts. "Drillium", it was called.
by mrfoo
Tue Mar 02, 2021 1:17 am
Forum: Pneumatic Cannons
Topic: Release a certain amount of air pressure from tank?
Replies: 2
Views: 306

Re: Release a certain amount of air pressure from tank?

What you're wanting to do, in order to get consistent shots, I think, is release a fixed amount of air at a fixed pressure. This is more complex, and yet more simple. Have one high pressure tank of large size. This feeds a small chamber, perhaps of variable size so you can tune it, via a regulator. ...
by mrfoo
Sat Feb 27, 2021 12:26 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: co2 tank to fill with air
Replies: 7
Views: 859

Re: co2 tank to fill with air

the bottle is actualy steel That's a good sign. Steel is far more resilient than aluminium. so it is has a working pressure of 1800 psi- 124 bar.... No, it *had* a rated working pressure of 1800psi, for CO2 only, in March 2001 when it was last hydrotested. Not sure what the acceptable period betwee...
by mrfoo
Fri Feb 26, 2021 12:57 pm
Forum: SpudFiles Discussion
Topic: Which side do we like the User Information on?
Replies: 4
Views: 555

Re: Which side do we like the User Information on?

I guess the verdict's in ;) Yep. With over a hundred views, only 4 people expressed a definite opinion. 2 more (myself included) stated that they didn't care (an option, in fact, which should have been "I couldn't care less", another case of overpondian mutilation of the beloved mother tongue), and...
by mrfoo
Fri Feb 19, 2021 11:48 am
Forum: BB, Airsoft, and Pellet Guns
Topic: co2 tank to fill with air
Replies: 7
Views: 859

Re: co2 tank to fill with air

Avoid beating off in public. It'll get you on a list. Sorry, that was a cheap joke. An aluminium tank can only, AIUI, be rated up to 3000 psi. That's around 200 bar, and the absolute maximum safe rating, tank direct from the factory, you can possibly expect. However, liquid CO2 only requires a bit m...
by mrfoo
Fri Jan 29, 2021 12:21 pm
Forum: Pneumatic Cannons
Topic: Multi Shots out of 100psi Tank
Replies: 12
Views: 1199

Re: Multi Shots out of 100psi Tank

Well that's bad advice. I let people know I was thinking of the children and I ended up on a shortlist.
by mrfoo
Wed Jan 13, 2021 6:37 am
Forum: BB, Airsoft, and Pellet Guns
Topic: 4,2 mm pipe for 4.5 ammo
Replies: 15
Views: 1885

Re: 4,2 mm pipe for 4.5 ammo

Hah, fuel filter.

Ironically, an off the shelf oil filter, intended to be used as such, might well do a better job. For example,



27dB is 512 times quieter.
by mrfoo
Thu Jan 07, 2021 3:58 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: 4,2 mm pipe for 4.5 ammo
Replies: 15
Views: 1885

Re: 4,2 mm pipe for 4.5 ammo

No, I understood that, I was suggesting a possible other approach. Crimping should work, as you suggest, use a mandrel of the desired size inside to avoid going too small. You can put a significant amount of pressure on with a drill chuck, but if it doesn't work you might look into finding someone w...
by mrfoo
Thu Jan 07, 2021 1:00 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: 4,2 mm pipe for 4.5 ammo
Replies: 15
Views: 1885

Re: 4,2 mm pipe for 4.5 ammo

Totally stupid idea, maybe, for use of bbs... What if you were to bend the barrel down slightly, right at the start by the breech? Would that perhaps force a consistent contact between bb and the top of the barrel, effectively guarantee a hopup effect even with the extra speed you're generating? A b...