SpudFiles

Have a look at this post

Basically, for a 1 inch barrel, the piston only needs to move back 1/4 of an inch for maximum performance, anything more is wasted air.

Pilot volume is defined as the volume behind the piston when the piston is closed. In a perfect world, when the piston is fully open, it should be zero.

The logic is simple really, for a pilot valve with a given flow, the smaller the pilot volume, the quicker the air is going to empty, therefore the piston moves back quicker.

It isn't a hard and fast rule though as there is such a thing as piston bounce however, have a look at this discussion.

Cool, thanx for those links. I guess it's time to start filling in some of the pilot's "dead space", and cut down on piston travel a hair....

jeepkahn wrote:It inverted the order of my pics, sorry...

Yeah the attachment facility built into Spudfiles is bad about that. Hosting your files at a place like Imageshack makes things a lot easier to deal with when posting. Use the "direct link" they provide.

Not a bad coax effort...your sawn reducer, barrel stand-off looks a little familiar...

starman wrote:

jeepkahn wrote:It inverted the order of my pics, sorry...

Yeah the attachment facility built into Spudfiles is bad about that. Hosting your files at a place like Imageshack makes things a lot easier to deal with when posting. Use the "direct link" they provide.

Not a bad coax effort...your sawn reducer, barrel stand-off looks a little familiar...

LOL, I figured I wasn't the first...

We need to try to put together a Southeast SpudJam...

jeepkahn wrote:We need to try to put together a Southeast SpudJam...

I think the toughest part is finding the shooting location. If we can come up with that, then it's just a matter of deciding on a date and inviting...maybe come up with some games and lots of damage opportunities.

I'll check around some in my area and see what I can come up with. I'll see if there are some standard shooting ranges that might accommodate us.

LOL you have got some very nice posters on the wall

starman wrote:

jeepkahn wrote:We need to try to put together a Southeast SpudJam...

I think the toughest part is finding the shooting location. If we can come up with that, then it's just a matter of deciding on a date and inviting...maybe come up with some games and lots of damage opportunities.

I'll check around some in my area and see what I can come up with. I'll see if there are some standard shooting ranges that might accommodate us.

I've got a 65 acre farm as well as another 40 that I lease, I've got a friend with a grass airstrip beside me, and we have a half mile of clear firing line backed by even more safe wooded land if we shoot beyond a half mile, and if you can get your trajectories right, We can shoot safely into a field from 1 to 1.5 miles....

We need video and chrony if someone has access...

P_S Thanx, I wondered if anyone would notice...

UPDATE!!! 1-24-2009:

I filled in a lot of dead space in the pilot volume area, and made a better "oneway" gasket for the piston, installed a 1/2" ballvalve to see if it would fire better, charged it to 40 psi dry, fired beautifully,filled to 85 psi(the line pressure where I work), fired beautifully... loaded a GB wrapped in kleenex, charged to 85 psi, at an angle of about 10 degrees I fired it into the woods 150 yds away... Couldn't even see the ball until it started cutting limbs off trees... YEEHA!!! And i don't even have my qev yet... I'm thinking maybe I'll use the qev on a new project since this is working so well with the ball valve... We'll see...

Also took sections of motorcycle innertube and stretched them over the fittings, this serves 2 purposes,1. a little bit of safety in case something cracks, and 2. to protect the fittings and joints from impacts from transportation and storage.... I'll post pics later... I'm also going to triple wrap the entire gun in black cloth duct tape....

POLAND_SPUD wrote:LOL you have got some very nice posters on the wall

No workshop would be complete without them

We need video and chrony if someone has access...

An F1 chrony is great and less than 100 of your finest American dollars, a worthwhile investment

jackssmirkingrevenge wrote:

POLAND_SPUD wrote:LOL you have got some very nice posters on the wall

No workshop would be complete without them

We need video and chrony if someone has access...

An F1 chrony is great and less than 100 of your finest American dollars, a worthwhile investment

BTW, thanx for pointing me in the direction of sorting out the pilot volume and piston travel, sometimes I read faster than my brain can assimilate what I'm reading...

As soon as I get a day off when the temps over 40f, I'll let you know how well it sends stuff downrange, It seems like the weathers nice until my day off and then BAM, Cold Front..lol...

jeepkahn wrote:

starman wrote:

jeepkahn wrote:We need to try to put together a Southeast SpudJam...

I think the toughest part is finding the shooting location. If we can come up with that, then it's just a matter of deciding on a date and inviting...maybe come up with some games and lots of damage opportunities.

I'll check around some in my area and see what I can come up with. I'll see if there are some standard shooting ranges that might accommodate us.

I've got a 65 acre farm as well as another 40 that I lease, I've got a friend with a grass airstrip beside me, and we have a half mile of clear firing line backed by even more safe wooded land if we shoot beyond a half mile, and if you can get your trajectories right, We can shoot safely into a field from 1 to 1.5 miles....

We need video and chrony if someone has access...

P_S Thanx, I wondered if anyone would notice...

65 acres + 40 + grass airstrip + safe wooded land sounds wonderful to me. My HD still-camera takes pristine photos and actually takes decent videos. I don't have a chrony but might invest in one if no one else has one. If we could set it up where the sun is behind us, it would make for the best time seeing, videoing, photographing...or ideally an overcast day.

It might be a little bit of a trip for our Ga contingent but you never know, we might attract some from who knows where. Let's talk it up some more. Mid-spring maybe before it gets too hot?

starman wrote:

jeepkahn wrote:

starman wrote:
I think the toughest part is finding the shooting location. If we can come up with that, then it's just a matter of deciding on a date and inviting...maybe come up with some games and lots of damage opportunities.

I'll check around some in my area and see what I can come up with. I'll see if there are some standard shooting ranges that might accommodate us.

I've got a 65 acre farm as well as another 40 that I lease, I've got a friend with a grass airstrip beside me, and we have a half mile of clear firing line backed by even more safe wooded land if we shoot beyond a half mile, and if you can get your trajectories right, We can shoot safely into a field from 1 to 1.5 miles....

We need video and chrony if someone has access...

P_S Thanx, I wondered if anyone would notice...

65 acres + 40 + grass airstrip + safe wooded land sounds wonderful to me. My HD still-camera takes pristine photos and actually takes decent videos. I don't have a chrony but might invest in one if no one else has one. If we could set it up where the sun is behind us, it would make for the best time seeing, videoing, photographing...or ideally an overcast day.

It might be a little bit of a trip for our Ga contingent but you never know, we might attract some from who knows where. Let's talk it up some more. Mid-spring maybe before it gets too hot?

I'll post a topic in general spud discussion to see if we can get the ball rolling...

Finally had some nice weather so I got to poke holes in stuff...

Note the captions with the pictures...

You have a nice range there. What exactly is picture 12?

more pics....

All shots were with 100 to 125 psi...

That's some nice shootin' there Jeep. I'm ready for that Spudjam...looks like you've got the space for it.