See how easy it is to compare and remember projectiles in grains.
I am shooting a nail dart with the speed and energy of a .38!
Good question about hose and quick disconnect.
I caught a bargain at Harbor Freight, 4 feet of 4,000 psi hose for $5!
I connected to a 3 foot section using quick disconnects so that when I get my Oxygen bottle fittings, I will be able to fill the bottle, switch hoses, and use the bottle away from the compressors.
The quick connects are 4 ball Commercial 1/4" type that Harbor Freight sells.
I have used them dozens of times at 600 psi without leaks.
The Females go for $3 and the Males for $1.
Be careful when buying quick disconnects.
They all look pretty much the same but you will quickly discover that you cannot fit one type into another.
My suggestion is to count the balls in the Female connector.
(That doesn't sound right).
The more balls, the more grab it has for higher pressure.
I have used 4 and 6 successfully at 600 psi.
(3 ball types are the cheaper auto tire changer style)
My $0.02.
Posted: Fri Apr 23, 2010 11:17 pm
by Mr.Sandman
Cool idea but seems a bit overkill in my opinion. The whole purpose of the piston valve was to be a step up from ball valves and sprinkler valves. Why not just pilot it with a qev piloted by a balla valve? Nonetheless great job 900 fps is a really nice fps and I think it will have a fair amount of power to it.
Posted: Sat Apr 24, 2010 7:12 am
by boyntonstu
Mr.Sandman wrote:Cool idea but seems a bit overkill in my opinion. The whole purpose of the piston valve was to be a step up from ball valves and sprinkler valves. Why not just pilot it with a qev piloted by a balla valve? Nonetheless great job 900 fps is a really nice fps and I think it will have a fair amount of power to it.
It is currently pressurized to 600 psi.
I intend to go higher.
A trigger offers consistency and accuracy.
Anything I can make for cheap, I make instead of buying.
Being a cheapskate is a major part of my hobby.
See my $100 elevator video here:
I feel more satisfied in making a safe elevator for under $100 than buying one for $20,000.
In use 7 years.
(No, my elevator does not meet any Building Code but it does meet mine.)
Posted: Sat Apr 24, 2010 7:13 am
by boyntonstu
Dup, server gave an error message.
Posted: Sat Apr 24, 2010 7:44 am
by deathbyDWV
Yep, looks ghetto but I bet it gets the job done. Good job...
Posted: Sat Apr 24, 2010 7:52 am
by boyntonstu
deathbyDWV wrote:Yep, looks ghetto but I bet it gets the job done. Good job...
Thanks.
I have been asked about the sear:
I just threw it together before going on a trip to try it out.
Not the finished set-up.
As for the sear, it is a 1" x 1" piece of scrap steel cut from a drapery rod L bracket that I found.
It had a hole in it large enough for a # 8 screw.
I cut a notch about 1/8" wide and 1/4" deep such that when the spring pulls the notch it lines up perpendicular to the line formed by the stretched spring and the screw holding the sear to the wood clamp.
The sear lines itself up and it will not move to release until it is rotated around its mounting screw.
Incidentally, I used the same screw for the wood clamp to mount the sear and at the muzzle to attach the spring.
The wood clamp at the muzzle is cut on one side and has just a single screw.
At the rear, 2 screws are needed to hold the 2 part wood clamp.
Next, I drilled a hole off to the side so that when I pulled, the sear would rotate away from the open end of the notch.
Using a fish scale, I measured 7 pounds of spring force and about 2 pounds of trigger pull.
Quite small and effective, I think.
Posted: Sat Apr 24, 2010 1:28 pm
by Hawkeye
What is this "pounds" you speak of?
Posted: Sat Apr 24, 2010 1:37 pm
by jackssmirkingrevenge
Hawkeye wrote:What is this "pounds" you speak of?
Oh please don't start
Have you tried without the extension on the ball valve handle? The closer you're pulling to the axis of rotation, the more the valve opens for the same spring movement (though of course the spring needs to be stronger to open at the same rate)
Posted: Sat Apr 24, 2010 1:59 pm
by Mr.Sandman
What I have found out which many other people probably have too, when using high pressure piston valves with a ballvalve pilot, If you angle the pilot vent down 90 degrees, The air rushing out of the pilot counteracts the recoil and allows the cannon to stay straighter during firing.
Posted: Sat Apr 24, 2010 2:03 pm
by maverik94
Yep, looks ghetto but I bet it gets the job done.
haha. thats exactly what I said.
Ghetto, but it looks like it gets the job done.
Posted: Sat Apr 24, 2010 3:49 pm
by Brian the brain
Why not just pilot it with a qev piloted by a balla valve?
Why not eat meata-balls every day?
The sprung ballvalve is very hot in France.As a main valve that is.
The idea certainly isn't new, but that's not a bad thing...it has proven itself already.
The new trigger allows you to build a stock around the gun..bullpup style..
Yeah baby!
If you angle the pilot vent down 90 degrees, The air rushing out of the pilot counteracts the recoil and allows the cannon to stay straighter during firing.
**Sawed-off by BTB thank you!!
The tromboyn has the same type of exhaust...