Search found 1731 matches

by Moonbogg
Thu Sep 16, 2021 5:07 pm
Forum: Ammo & Parts
Topic: What caliber ammo is most available In 2021?
Replies: 3
Views: 8359

Re: What caliber ammo is most available In 2021?

Potato caliber, lime caliber, golf ball caliber, and soda can caliber are all readily available in my local area.
by Moonbogg
Tue Sep 14, 2021 6:09 pm
Forum: Hybrid Cannons
Topic: Wires and Walls.
Replies: 2
Views: 4680

Re: Wires and Walls.

I've drilled holes and fed wire through an aluminum chamber and used epoxy to seal it. It's been 12 years and it still works. Another more recent cannon I made uses a spark plug. Drill and tap a hole and stick a spark plug in there. Well, the spark plug went through an end plate, not the chamber. Bu...
by Moonbogg
Sun Sep 05, 2021 2:37 pm
Forum: Hybrid Cannons
Topic: MAPP Gas Safety
Replies: 3
Views: 4270

Re: MAPP Gas Safety

I'm no expert, but people have used MAPP gas for combustions and hybrids for a long time. There's no issue compressing MAPP gas in a metering pipe for fueling a cannon as long as it's a metering pipe and not some kind of tank where you add MAPP and AIR (or any form of oxidizer) for a pre-mixed fuel ...
by Moonbogg
Mon Aug 30, 2021 5:48 pm
Forum: Hybrid Cannons
Topic: Thoughts on my piston valve design
Replies: 41
Views: 28203

Re: Thoughts on my piston valve design

Are the fittings aluminum? I'm not familiar with the fittings you are going to use. I also don't know why commercial fittings are given the pressure ratings that they have. With PVC it's obvious, but if galvanized iron says 150psi then that seems strange to me but I'm sure there's some reason. Maybe...
by Moonbogg
Sat Aug 28, 2021 11:02 pm
Forum: Hybrid Cannons
Topic: Thoughts on my piston valve design
Replies: 41
Views: 28203

Re: Thoughts on my piston valve design

Based on your shown areas, I got 1143 psi chamber pressure for equalization, so the same that you got. It looks like this is an estimate though because it looks like you clicked the surfaces and there are chamfers on them, so the actual diameters will be a little larger, but it should be pretty clos...
by Moonbogg
Thu Aug 26, 2021 2:53 pm
Forum: Hybrid Cannons
Topic: Thoughts on my piston valve design
Replies: 41
Views: 28203

Re: Thoughts on my piston valve design

Good to see you back. Designing is a big part of the fun, so I look forward to you working on it some more.
by Moonbogg
Thu Aug 19, 2021 1:35 pm
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 18
Views: 13262

Re: Hybrid Piston Pilot Air Ratio

I thought the same thing about the piston. It looks machined for sure and very nice!
by Moonbogg
Sun Aug 15, 2021 11:27 pm
Forum: Off-Topic Hobbies
Topic: I CAN HAZ MILING MACHIEN?
Replies: 4
Views: 7547

Re: I CAN HAZ MILING MACHIEN?

Very nice! That's a good way to bargain: twice the scrap rate. Looking forward to your progress on getting it up and running. Congrats!
by Moonbogg
Sat Aug 14, 2021 3:50 pm
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 18
Views: 13262

Re: Hybrid Piston Pilot Air Ratio

Thanks for the explanation. Now I get it. Like you said, the o-ring isn't supported from the outside, so it stretches and just comes off the rod when you shoot it. I agree that a harder o-ring is the best experiment to try next. If all else fails, you can try to modify the valve with a sealing face ...
by Moonbogg
Sat Aug 14, 2021 12:08 am
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 18
Views: 13262

Re: Hybrid Piston Pilot Air Ratio

Does the small o-ring pass over a port while under pressure? If so, it's like running the o-ring over a cheese grater. You might try a different shaped o-ring, such as the X shaped ones. They have much less friction when squeezed, but there would still be friction caused by pressure. They might work...
by Moonbogg
Tue Jul 20, 2021 5:32 pm
Forum: Pneumatic Cannons
Topic: Rate my cannon
Replies: 11
Views: 7176

Re: Rate my cannon

Nice cannon. You're taking a significant risk by using PVC with that much pressure inside. It can fail within it's rated pressure for no apparent reason because it's plastic and it tends to be fragile. It won't just crack, split or tear, but it will fragment and explode in your face. Wear safety gog...
by Moonbogg
Wed Jul 07, 2021 2:49 am
Forum: General How-To & Discussion
Topic: Hacksmith of potato guns?
Replies: 6
Views: 7252

Re: Hacksmith of potato guns?

Honestly I think people would be asking for different content pretty fast. Take note of the slingshot channel. It's called the slingshot channel, yet he does way more than make slingshots. He holds true to the basic concept by mostly using rubber for power. I'm not sure potato guns could be as diver...
by Moonbogg
Tue Jun 29, 2021 8:53 pm
Forum: Pneumatic Cannons
Topic: Tennis ball launcher
Replies: 3
Views: 3943

Re: Tennis ball launcher

Very cool. I made a tennis ball cannon in high school from a rolled and welded sheet like that. It worked perfectly and I bet yours will too.
by Moonbogg
Tue Jun 29, 2021 5:58 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Victorian "Air Cane" brought back to life
Replies: 29
Views: 24784

Re: Victorian "Air Cane" brought back to life

The damage video was fun to watch. This was a great project.
by Moonbogg
Tue Jun 29, 2021 5:43 pm
Forum: Hybrid Cannons
Topic: Hybrid Piston Pilot Air Ratio
Replies: 18
Views: 13262

Re: Hybrid Piston Pilot Air Ratio

Is this a vented pilot design? I worked the numbers for an 8X mix and a 75% of maximum opening pressure for the piston. Same pressure in the pilot as the preignition chamber pressure. I get a pilot piston diameter of 16.73mm (assuming a 6.5mm piston diameter chamber side), so basically the same as M...