600 psi 3/4" QEV Launcher

[jeepkahn]

Peashooter was not a statement made for negativity purposes...

It was made half in jest because it is so powerful... I forget that typed words don't show inflection....

But, if someone said that 2lbs of C-4 was a sweet firecracker, I'm sure that there would've been no mistaking the intent of the comment...

[Dave_424]

hey, i know this is thread grave digging but there are some unanswered questions

I did not do anyhing to the QEV to handle the pressures

I opened it up the other day and saw no damage

I have used th fridge compressor to 1000psi quit a few times (On an air rifle)

Just going to give it a makeover so be ready for some long range shots (50, 75, and 100 yards)

just need to find a good projectile and a way to mount my scope:P

Dave

[jackssmirkingrevenge]

a way to mount my scope:P

jook13 had a brilliant idea here using a scope mount clamp

[c11man]

for prjectile you could look at buying the acual bullet without a shell

a store just 2miles from me will sell bullets ranging from a 22 all the way up to 50 cal. (no they do not carry the 50cal in stock) theyalso sell them in full jacket and all the rest of the diffent types

so if you got a barrel close to say a 30-06 bullet and attached a tail made out of some fuzzy stuff because you probably wont have a rifled barrel

i am sure that MANY places sell bullets online so its shouldnt be very hard to find some

[Ragnarok]

i am sure that MANY places sell bullets online so its shouldnt be very hard to find some

In the US perhaps - but Dave_424 lives in the UK (at least, based on the parts he has used). Suffice to say, bullets are not as easy to find in the UK, especially in the calibres you'd need for this.

So you know, polls suggest that around one third of the forum's members are not from the US, so it's best to not get into automatically assuming that everyone is American.

Interestingly, the nationality split actually gets higher when you consider just the really big posters. Of the top ten posters, no less than 6 are from outside the US. If you want my guess, I figure that's probably because we don't have gunstores 2 miles away.
After all, if you have two ballistics addicts, one of whom can purchase and own production firearms, and the other of whom can't - which one is more likely to "do it themselves"?

[c11man]

sorry for assuming... it makes and you know what out of you and me...

besides ball bearings i dont realy have any ideas

[Ragnarok]

sorry for assuming...

Nah, it's not really a problem. It's just something to be aware of. You'll get an eye for it after a while here.

Indeed, your advice would have been perfectly valid for many of our members. I only really brought it up here because there had already been a mention of nationality in the thread.

[Dave_424]

hey guys, did some long range shooting today, only managed 50 and 75 yards because I ran out of land

just putting the video on youtube now and will post it when it is on

for attaching a scope, I did think of the scope rail clamp but because I have a 15mm barrel it would ave been hard. How I did it was I just took the breach off my air rifle and attached it onto the top of the gun

Dave

Here is the link

[Biopyro]

AA batteries are good when you remove the plastic cover (cheaper brands)
If you have any polymorph, first use a round file to remove all burrs from the inside of the barrel.
Then, heat it up the polymorph, and force it down the barrel while soft. make the back half hollow. Leave it to cool inside the barrel for the best fit, or use a freezer for a worse (too tight, so higher friction) fit.
If you don't have any polymorph, get some! It's great for making perfect fitting ammo in metal barrels.
Do check out the wiki for ammo ideas, and add any new ones you have in there. (feel free to PM me to do it too. I like to take care of the ammo section ad it's a bit of a hassle adding things into that table.)
http://www.spudfiles.com/spud_wiki/index.php/Ammo

[Dave_424]

cheers for that biopyro

I am going to cast some lead slugs in a barrel offcut, hopefully I will get some good penetration, some nice tropy mushroomed slugs and some amazing recoil

Dave

[Biopyro]

Oh yeah, I forgot to mention about the polymorph. It never usually gets stuck, but once it did (the pipe was lined with soot which I think caused it), so try to do it in an offcut. The bullets are a veeery tight fit, but also really low friction because of their even shape. They would make a great pistons.

[Technician1002]

AA batteries are good when you remove the plastic cover (cheaper brands)
If you have any polymorph, first use a round file to remove all burrs from the inside of the barrel.

http://www.spudfiles.com/spud_wiki/index.php/Ammo

I started a new thread for this valve here;
http://www.spudfiles.com/forums/quick-d ... 17858.html

For when I had to make a valve body out of iron pipe, I used a wooden dowel and sandpaper. I split the dowel so it would expand as I wedged stuff in the split as the pipe ID wore larger.

I had to have a very smooth finish as the valve was using o rings. Info on the cannon is on crazybuilders in the forum.

I built a smaller version in a 1 inch pipe and built it in a disposable propane cylinder. I put together a youtube video on how the Quick Dump Valve works.

[youtube][/youtube]

I added the obligatory damage video of an orange hitting something a high speed.
[youtube][/youtube]

More videos of my launchers are here;

http://www.youtube.com/user/Technician1002

[Biopyro]

wow what a coincidence! I'm on crazy builders too and was so impressed with the concept of the quick dump valve, I'm building one now. Just working on the piston at the moment.
I've decided to do it a little differerently, by having a string on the back for the pilot mechanism.

[Technician1002]

wow what a coincidence! I'm on crazy builders too and was so impressed with the concept of the quick dump valve, I'm building one now. Just working on the piston at the moment.
I've decided to do it a little differerently, by having a string on the back for the pilot mechanism.

Before you cut the grooves for the o rings, wait for a new post on o rings in my thread.

http://www.spudfiles.com/forums/quick-d ... 17858.html

I'm planning on doing a part on the construction of my quick dump valves. How the o rings fit and the friction from tight rings with a fix are covered.

A a sneak preview.. The o rings are loose in the groove so they can wobble. The groove is deep so the o ring isn't pinched between the valve body and the bottom of the groove. How it is made so it doesn't leak will be covered later. These rings don't make the piston stick.

As far as a string trigger, been there, done that. My ABS apple cannon is that design exactly. It's a coaxial 2 inch barrel inside a 4 inch ABS chamber. If you were local, I would give it to you. I am retiring it.

A photo of it can be seen on;

https://inteltrailblazerschallenge.wiki ... com/Photos

It's the small photo near the bottom of the page.

It launches apples in the 550 foot range at 60 PSI. The pressure is kept low because this is cellular core ABS DWV pipe. Due to it's length, the easy way to trigger it was to attach a golf ball to the end of the string. The cannon is loaded, pressurized, (Never load one under pressure, it will go off!) and stood on end. The golf ball string is stepped on and the cannon lifted to pull the string tight. It sounds complicated, but it isn't. To fire, simply lift the cannon while leaning it down range.

This made it quite safe for the camp that uses it. The barrel is always overhead when fired. Nobody can be in the way as it is always pointed skyward when fired as the breech is on the ground.

[Butch902]

isn't the max psi rating for a 3/4'' QEV 150- 175max?