Search found 3627 matches

by mark.f
Sun Nov 19, 2023 9:56 pm
Forum: Hybrid Cannons
Topic: Mini Hybrid II
Replies: 11
Views: 26103

Re: Mini Hybrid II

jackssmirkingrevenge wrote:
Thu Nov 16, 2023 1:10 pm
That's a hell of a BB gun. :D
by mark.f
Sun Nov 19, 2023 12:08 pm
Forum: Pneumatic Cannons
Topic: Valve reliability
Replies: 7
Views: 8962

Re: Valve reliability

Reliability stacks, the more parts, the more often the machine stops. Theoretically, a spool valve like you built with one moving part should be very reliable. However, you probably need to look into how the seals on DCV's are done, O rings rarely like to move past porting, having the o-rings seal i...
by mark.f
Sat Nov 11, 2023 4:10 am
Forum: Hybrid Cannons
Topic: Mini Hybrid II
Replies: 11
Views: 26103

Re: Mini Hybrid II

He's still at it! Nice work as always.
jackssmirkingrevenge wrote:
Thu Nov 09, 2023 12:26 pm
Here is what it looks like internally, if it seems a little unusual that's because it's actually part of another project that I will share at a later date:
Cryptic as always. ;) Does it have to do with cartridges?
by mark.f
Sat Nov 11, 2023 4:06 am
Forum: Hybrid Cannons
Topic: Hybrid disk burst pressure effect on performance
Replies: 20
Views: 28288

Re: Hybrid disk burst pressure effect on performance

Interesting find, we definitely need some more test data on hybrids to improve the modelling others have done.
by mark.f
Wed Nov 08, 2023 6:46 am
Forum: Pneumatic Cannons
Topic: fl(air) gun - mechanically locked pneumatic cartridge for a 26.5mm flare gun
Replies: 13
Views: 29436

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

Any other stand out builds or ideas on here over the last 10years I’ve been absent? My holy grail would still be a large caliber cartridge ejecting semi auto. I should complete that QEV repeater build one day. There's been a lot of small and intricate hybrid builds especially by hectmarr. But ten y...
by mark.f
Fri Oct 20, 2023 4:19 pm
Forum: Combustion Cannons
Topic: Ideal C:B ratio?
Replies: 3
Views: 3271

Re: Ideal C:B ratio?

The 0.8:1 ratio comes from burntlatke's testing where chamber volume was held constant and barrel volume was changed, which effectively found the longest barrel length that could efficiently use a certain chamber size. Increasing chamber size up to a certain point will just lose efficiency. You coul...
by mark.f
Mon Oct 16, 2023 10:00 am
Forum: Combustion Cannons
Topic: Dose UKARA cover spud guns in the uk
Replies: 6
Views: 5283

Re: Dose UKARA cover spud guns in the uk

I'm obviously no expert but every time I heard our (now inactive) UK members talk about airguns they almost always mentioned muzzle energy restrictions.
by mark.f
Fri Oct 13, 2023 5:14 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Homemade semi-automatic pellet gun help.
Replies: 1
Views: 7937

Re: Homemade semi-automatic pellet gun help.

So does it fire from an "open bolt" or closed? Like are the solenoid and solenoid valve energized simultaneously?
I would hazard a guess it has to do with your power supply and isolation between the solenoids but a little more detail could help.
Also that sounds awesome, hope you share soon!
by mark.f
Fri Oct 13, 2023 5:07 pm
Forum: Pneumatic Cannons
Topic: PVC and ABS pipe for the barrel
Replies: 5
Views: 3712

Re: PVC and ABS pipe for the barrel

Like pennywise said, depends.
I don't think anybody's actually measured it but using HGDT usually shows higher pressures in the barrel when modelling hybrids.
by mark.f
Fri Oct 13, 2023 5:04 pm
Forum: Pneumatic Cannons
Topic: High pressure 50cal rifle
Replies: 6
Views: 4913

Re: High pressure 50cal rifle

Obviously looks great! Speaking to the silencer, are you planning to use the extra length of lower tube for expansion volume? If you're beating your head against the wall trying to figure out how to rifle the barrel, and you have a 3d printer, you can take a look at electrochemical rifling . Good jo...
by mark.f
Tue Apr 04, 2023 8:50 pm
Forum: Pneumatic Cannons
Topic: Complex yet small regulator with multiple preset options possible?
Replies: 3
Views: 3391

Re: Complex yet small regulator with multiple preset options possible?

It sounds like you just need a venting regulator if I'm reading correctly.
by mark.f
Tue Apr 04, 2023 7:36 pm
Forum: Off-Topic Hobbies
Topic: "Offtopic-posts-topic" NSFW
Replies: 6637
Views: 1330647

Re: "Offtopic-posts-topic" NSFW

jackssmirkingrevenge wrote:
Mon Mar 13, 2023 9:49 am
MP5
Now I guess you need Rit-job STABO and ALICE gear, a flight deck helmet, and a balaclava. :lol:
by mark.f
Mon Oct 03, 2022 11:49 pm
Forum: Off-Topic Hobbies
Topic: Low price HPA "sodastream" bottle
Replies: 3
Views: 4376

Re: Low price HPA "sodastream" bottle

That's cool but would it be better than something like this? I was actually about to pick up a tank and pump for a future project.
by mark.f
Thu Sep 29, 2022 5:02 pm
Forum: General How-To & Discussion
Topic: Short question topic
Replies: 1502
Views: 522751

Re: Short question topic

Same thing can happen easier with oxygen tanks, but I probably don't have to sit down and do the chemistry to see how much of a few grams of petroleum grease can do in a sealed oxygen rich environment, even if it is an HPA tank. :P
by mark.f
Tue Sep 27, 2022 8:55 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Sneak peek
Replies: 4
Views: 4561

Re: Sneak peek

Is it an "AEG" type mechanism hooked up to an air turbine? That would be neat but pretty inefficient if we're talking about using air to propel airsoft BBs. :P