Search found 231 matches

by High-PSI
Sat Aug 03, 2013 9:35 pm
Forum: Pneumatic Cannons
Topic: Custom Aluminum Pneumatic Build
Replies: 109
Views: 34799

I have to chime in here; First, beautiful work! Second, that thing should be good for 500 psi or higher. I would pressure test the tank to 800 psi and start firing it at 500 (assuming you can get access to that kind of pressure). Oh, as for the piston bump stop, my 1 inch bore cannon uses an aluminu...
by High-PSI
Sat May 11, 2013 12:55 pm
Forum: Pneumatic Cannons
Topic: My first 2" cannon (just something little) :)
Replies: 113
Views: 21729

Hey Guys, A little update; I have begun firing at over 400 psi. That is 30 to 40 psi higher than previously. That may not sound like much of an increase, but I was getting used to it before and now it is way more powerful. I fired at a target on top of a 4x4 post and it fired straight through the po...
by High-PSI
Tue Jun 05, 2012 3:43 pm
Forum: Pneumatic Cannons
Topic: Experimental machined HPA 1 inch valve
Replies: 12
Views: 3878

Do you have any pictures you can post?

Matt
by High-PSI
Tue Jun 05, 2012 7:37 am
Forum: Pneumatic Cannons
Topic: Experimental machined HPA 1 inch valve
Replies: 12
Views: 3878

I am in the process of converting my 1/2 inch bore rifle to use this valve. I will report back on the performance when I have more data. I have fired the valve at over 800 psi at this point and it operates wonderfully. Like anything, there are benefits and drawbacks to any design. My big 2 inch cann...
by High-PSI
Mon Jun 04, 2012 8:54 pm
Forum: Pneumatic Cannons
Topic: Experimental machined HPA 1 inch valve
Replies: 12
Views: 3878

Hmm, I would wonder about the liability.

The big issue is, the valve body of this is $55. The pilot valve is $80, and the rest of the machining would cost about $55 to $65 more.

This stuff does get pricey.

Matt
by High-PSI
Tue May 15, 2012 7:40 am
Forum: Pneumatic Cannons
Topic: HPA pistol musings........
Replies: 27
Views: 6294

What you could do is make the piston diameter only slightly larger than the seat diameter. This will give you better porting but it will also make the piston pop open faster. The air has less surfaceon the front to push on when it is closed position , so the pilotpressure needs to drop further befo...
by High-PSI
Tue May 15, 2012 7:04 am
Forum: Pneumatic Cannons
Topic: HPA pistol musings........
Replies: 27
Views: 6294

Yes. There is very little difference in the performance with a varied piston mass. One interesting thing, however; The accelleration curve changes with a nearly identical exit velocity. What GGDT shows is a very different behaviour in the barrel when the vent diameter and piston weight changes, whil...
by High-PSI
Tue May 15, 2012 5:57 am
Forum: Pneumatic Cannons
Topic: HPA pistol musings........
Replies: 27
Views: 6294

OK, I am moving ahead with this gun build. I have a question on this that I wanted your opinion on; GGDT shows no noticeable change in muzzle energy or velocity with various changes in vent diameter size. I programmed it for 800 psi with a pilot volume of 1.5 cubic inches (a .8 inch barrel coax desi...
by High-PSI
Mon May 14, 2012 3:59 pm
Forum: Pneumatic Cannons
Topic: Two stage fridge compressor build
Replies: 48
Views: 10172

Hey Guys, I have some more info for you.......... First, I found that the old style start relays allow the compressor to stall and restart without waiting 60 seconds like the solid state relays do. Next (and this is something cool I just learned), compressors have an LRA rating. I learned that stand...
by High-PSI
Fri May 11, 2012 9:05 pm
Forum: Pneumatic Cannons
Topic: Experimental machined HPA 1 inch valve
Replies: 12
Views: 3878

Experimental machined HPA 1 inch valve

This valve started as a one inch diaphragm valve that has a bad cap and diaphragm. So, starting with just the valve body, I machined a cylinder and piston to convert it to a proper piston valve. I recently blew the diaphragm in an identical valve at 600 psi. So, I wanted to see how much pressure I c...
by High-PSI
Thu May 10, 2012 5:39 pm
Forum: Pneumatic Cannons
Topic: So, whos is in northern Illinois?
Replies: 4
Views: 1602

So, whos is in northern Illinois?

Hey Guys,

Who here is in Northern Illinois? I am in McHenry county and I am looking for others to shoot with.

Anyone from the forum nearby?

Matt
by High-PSI
Thu May 10, 2012 7:17 am
Forum: Pneumatic Cannons
Topic: Slightly off topic, interesting project/situation.......
Replies: 16
Views: 3530

We are talking past each other. When I am talking about shutting off the feed to the chamber, I am also assuming the entire chamber will not be dumped. The chamber will remain sealed when the trigger is pulled. Only after the trigger is pulled and released will the cylinder be allowed to exhaust, ye...
by High-PSI
Wed May 09, 2012 12:44 pm
Forum: Pneumatic Cannons
Topic: Slightly off topic, interesting project/situation.......
Replies: 16
Views: 3530

None of these make sense. Don't you think it's a bit naive to assume that over the last 50 yrs or so no one tried to improve efficiency of nailguns ? It's also a bit naive to say that nail guns have reached the peak of their development and can't possibly be improved. Manufacture is always a compro...
by High-PSI
Tue May 08, 2012 5:57 pm
Forum: Pneumatic Cannons
Topic: What would you Guys build?
Replies: 76
Views: 12476

OK, question; Would you guys focus on accuracy and muzzle velocity (as far as doing work to improve this gun), or muzzle energy as in a larger bore? This valve CV is 14. So, a 1 inch barrel is good with this valve and gun. GGDT shows a muzzle energy increase from my current 171 ft lbs to 428 ft lbs ...
by High-PSI
Tue May 08, 2012 3:44 pm
Forum: Pneumatic Cannons
Topic: Slightly off topic, interesting project/situation.......
Replies: 16
Views: 3530

Slightly off topic, interesting project/situation.......

Hey Guys, A friend of mine is CEO of an air nailer company. He and I began talking about his nailers. I asked him questions regarding trigger air useage, tank to cylinder ratio, etc. He had no clue. So, as the conversation wore on, I asked if he would like me to research his nailers to see if I can ...