Search found 3599 matches

by mark.f
Fri Jul 23, 2021 6:27 am
Forum: Pneumatic Cannons
Topic: Rate my cannon
Replies: 11
Views: 329

Re: Rate my cannon

Interesting, just out of curiosity, have you thought about modifying the angle seat valve to be outlet-sealing like this? (He made it out of a wye strainer though).
by mark.f
Tue Jul 20, 2021 8:42 am
Forum: Pneumatic Cannons
Topic: Rate my cannon
Replies: 11
Views: 329

Re: Rate my cannon

rookie builder wrote:
Sun Jul 18, 2021 8:52 pm
What is a balance tap?
It's just lead connected between the two cells for your charger to connect to to keep the voltages equal when charging (and discharging too if you use a battery management system, homemade or otherwise).
by mark.f
Mon Jul 19, 2021 3:13 pm
Forum: Pneumatic Cannons
Topic: Paintball Artillery Gun
Replies: 8
Views: 655

Re: Paintball Artillery Gun

It might be worth giving this a read, or at least a quick skim: FM 3-22.90.
Not too familiar with mortars myself, as the only time I got to watch a team they fired a total of two flares. :P
by mark.f
Sun Jul 18, 2021 7:52 pm
Forum: Pneumatic Cannons
Topic: Rate my cannon
Replies: 11
Views: 329

Re: Rate my cannon

Neat valve. I'd like some more details but I'm with @farticox1, that's a lot of pressure for PVC.
But even with all of that, I think what would worry me more is if there was no balance tap on that battery pack you wired up. :D
by mark.f
Wed Jul 07, 2021 8:22 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: My first Cool Wall
Replies: 3
Views: 258

Re: My first Cool Wall

Weaponize the water heater.
In other news dope wall. :D
by mark.f
Tue Jul 06, 2021 7:55 pm
Forum: General How-To & Discussion
Topic: Hacksmith of potato guns?
Replies: 6
Views: 347

Re: Hacksmith of potato guns?

there are only a few designs I could do without a decent shop That's where I think you could set yourself apart. There's tons of channels like hacksmith where the dudes 3d print entire builds and send off for some PCB's for the electronics. I'd personally watch the shit out of a channel with a JSR-...
by mark.f
Tue Jul 06, 2021 11:41 am
Forum: General How-To & Discussion
Topic: Hacksmith of potato guns?
Replies: 6
Views: 347

Re: Hacksmith of potato guns?

I think it's a little too focused but there's definitely a niche that could be filled. For instance, searching for hybrid cannons brings up minecraft videos and MrCrowley's. :p Just starting out you'll probably have to mix-in "theory" and "build progress" videos since it's a little ambitious to buil...
by mark.f
Tue Jun 29, 2021 6:23 pm
Forum: Pneumatic Cannons
Topic: Tennis ball launcher
Replies: 2
Views: 253

Re: Tennis ball launcher

I think it will too. For whatever it's worth, I say mount the barrel with the seam at the top and pray for a backspin. :D
by mark.f
Mon Jun 28, 2021 5:17 am
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 8
Views: 525

Re: Hybrid Piston Pilot Air Ratio

Ah, so you're using a chamber/outlet sealing design. That makes more sense. So are you trying to find the right sized piston so that you can use equal (before ignition) chamber and pilot pressures and still get opening at an optimal (higher) pressure? If so you could probably play around with GasEq ...
by mark.f
Sun Jun 27, 2021 6:50 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Victorian "Air Cane" brought back to life
Replies: 24
Views: 2827

Re: Victorian "Air Cane" brought back to life

Yes, I am bumping this thread because I missed the final product after my annoying suggestions. :D Great work as always!
by mark.f
Sun Jun 27, 2021 6:36 pm
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 8
Views: 525

Re: Hybrid Piston Pilot Air Ratio

You want the barrel seat (outlet) and the piston to be closer in size for higher opening pressures for a given pilot pressure. To get the cracking pressure of your valve it's just P_c=(P_p*A_p)/A_c, where: P_c=cracking chamber pressure P_p=pilot pressure A_p=pilot area A_c=chamber area So with an 8m...
by mark.f
Wed Jun 23, 2021 7:47 pm
Forum: Combustion Cannons
Topic: Oxy/Acetylene mini cannon questions.
Replies: 21
Views: 7031

Re: Oxy/Acetylene mini cannon questions.

Can someone just please post an answer instead of always ratios and different things just how about what psi should we set the gauges to for oxy acetylene. How much for a non-oxygen environment and How much for a regular oxidated environment ie a ballon compared to a combustion chamber . 8 ace and ...
by mark.f
Sat Jun 19, 2021 2:13 pm
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2454
Views: 235156

Re: "In the world of spuds today"

The temptation is always there to "count out" electronics as innovation, but with the energy density (and miniscule internal resistance) of modern batteries getting better and better, things like direct-action solenoid hammers and electromechanical loading could probably (definitely) lead to obscene...
by mark.f
Fri Jun 18, 2021 3:34 pm
Forum: Combustion Cannons
Topic: Pressure Rated PVC Fittings
Replies: 1
Views: 229

Re: Pressure Rated PVC Fittings

It's obviously better to use pressure rated fittings, but in the past me and many others have used DWV fittings for simple combustions. That said, I'd recommend looking on mcmaster and getting what you need. To replace the cleanout adapter and plug just get a threaded adapter and a SCH-80 threaded p...
by mark.f
Thu Jun 17, 2021 10:38 am
Forum: Pneumatic Cannons
Topic: Paintball Artillery Gun
Replies: 8
Views: 655

Re: Paintball Artillery Gun

Just as a matter of opinion: cam locks all day every day. :P In a mounted configuration like yours screw breech works well enough, but any usage where the barrel is free to move in any other axis than forward/backwards (and rotating) they become very annoying.