Luka () Sat Nov 27 2010 10:42 PM	Airgun take two
	I am in the process of building a one inch piston valve. Once done, I'll mount the half inch barrel, and the 2 inch chamber to it. I want to see how much difference, if any, I will get with a larger piston valve on essentially the same airgun as the half inch airgun I presented at the end of the last thread. I'll build the valve first. Once it is working then I'll decide on the barrel, chamber, etc. An option I may go with, instead of the 2 inch chamber, is a 1-1/4" chamber instead. If I go with the smaller chamber, it will be because of looks, as well as a better possibility to get the entire airgun built to look more like a 'real' gun. Two builds I am considering for the future are 1. A "coaxial" air gun. Where the piston and barrel are housed -inside- the chamber... And 2. Possibly an attempt to try to make a full size replica of something like the guns in "District 9"... But as working airguns... Right now, though, I am still very much a newby to this. I have a lot to try, and to learn, before I can make anything like a working airgun replica of something else. I have a lot of stuff running through my head. Ideas that I'd like to try. Like heating PVC to malleable, leather-like states, to build things such as stocks, recievers, etc. Non-pressurized parts. And working with bondo, brass, aluminum and other ways to make these things look 'pimped out'. LOL Cost will be, as always, the major limiting factor. But then, that's part of why I want to do things the way I want to. To try to keep costs down. Just as working with that half inch valve until I got it to work without having to include the sprinkler valve. I do think that unless I can come up with a faster flowing homemade pilot valve, of my own, valves in the range of 1-1/4" and larger are going to have to be piloted by sprinkler valves. (Which are in turn piloted by blowguns.) One idea I have for a pilot, is an ordinary pressure relief valve. The kind used on compressors. They 'pop-off' at a certain pressure, in case the compressor regulator switch goes kerplooey, and the compressor just keeps pumping away. Keeps it from blowing up. LOL If that doesn't flow fast enough, I will probably try a few ideas I have with fittings, springs, bolts, and o-rings. ~~~ So much to do, so little resources. Including volition. But then, keeping the volition stoked, is part and parcel to my reasoning for doing all this... ~~~ Next, some pics.
Luka () Sat Nov 27 2010 10:45 PM Attachment	Re: Airgun take two
	I'll try to keep better track of the progress on this one. More pictures. Maybe better explanations. (If you have any questions, feel free to ask.) ~~~ Like I said, I am going to build the valve first. Once it is actually working, then I'll tend to the rest of the build. From left to right... The barrel stub. A 1" to 3/4" reducer fitting. 1" tee. 1" pipe that will become the piston chamber. 3/4" pipe that will become piston. Wood dowel. This has been wrapped with tape, to make a very snug fit inside the 3/4" pipe. It will be epoxied into the pipe. Then the outside of the pipe will be reduced in size until it fits tightly within the 1" pipe section. The wood dowel is longer than the 3/4" piece of pipe, because the dowel is to stick out the front of the piston, and have the barrel sealing face affixed to it.
Luka () Sat Nov 27 2010 10:52 PM Attachment	Re: Airgun take two
	Second pic. The parts essentially the way they will look, when assembled. The dowel is on the wrong side of the 'piston', but you get the idea.
Luka () Sat Nov 27 2010 10:55 PM Attachment	Re: Airgun take two
	This is the 1" to 3/4" reducer. This will be inserted into the 1" tee, and the barrel stub will be pushed through it, into the position needed, to make a barrel seal with the piston. The fitting had a 'stop' in the end of it, to keep the 3/4" pipe from going all the way through. Of course, I WANT the 3/4" pipe to go all the way through. LOL So, I have to hog out that 'stop' in the end. This pic shows one fitting with the stop still there, and one fitting already hogged out, to allow the pipe to go all the way through. That isn't as easy as it may seem. You have to be patient and persistant, to get it hogged out just enough, but not too much. And to keep it from becoming out of round.
Luka () Sat Nov 27 2010 11:04 PM Attachment	Re: Airgun take two
	Next, a pic of the 'barrel stub' sticking into the tee. Most people run the barrel to the center of the tee. I don't like to go that far. I prefer a compromise distance. One that can still be reached without over-centering the piston, and risking it jamming... But still far enough back, to allow more free air flow, once the piston unseals from the barrel. In the pic, you can see the seam that is the center of the tee.
Luka () Sat Nov 27 2010 11:07 PM Attachment	Re: Airgun take two
	In this pic you can see that the wooden dowel has been epoxied into the 3/4" pipe. It is sitting beside the 1" pipe that it will have to be made to fit inside of. It almost fits inside, already. It shouldn't take much 'lathe' work on the drill press, to get it to the point where it is a tight fit.
Luka () Sat Nov 27 2010 11:10 PM Attachment	Re: Airgun take two
	And this is the last pic for the night. The piston is laying beside the rest of the 'valve', in the position it should be sitting, once the valve is put together. I should be getting that piece worked on pretty soon. I have some thngs to take care of first, due to the recent snowfall. I'll be back to show progress, whenever there IS any...
Luka () Tue Nov 30 2010 08:58 PM Attachment	Re: Airgun take two
	I've taken a bit of a different tact with this piston. Instead of building up on something that was too small, I will use my benchtop drill press as a sort of vertical lathe. I'll use it to reduce the OD of the 3/4" pipe which is the piston, until it slides into the one inch pipe. To do this, I'll drill through and insert a bolt. Then chuck the bolt into the drill press. And use sandpaper and files on the piston, until it is the right diameter. Here are the materials. The piston, the bolt, nuts, and bearing.
Luka () Tue Nov 30 2010 09:05 PM Attachment	Re: Airgun take two
	To make the bearing work, I have to reduce the size of the head of the carriage bolt. I chuck that into the drill press, and then use the file, while the drill press is running.
Luka () Tue Nov 30 2010 09:18 PM Attachment	Re: Airgun take two
	Now I can install the bolt into the piston. Chuck that into the drill press. Clamp the bearing in the vise. Run the drill press down just enough to set the turned down head of the bolt into the bearing. This will prevent wobble, which would cause the piston to end up out of round.
Luka () Tue Nov 30 2010 09:27 PM Attachment	Re: Airgun take two
	This is the finished piston. (Well, without the washers and rubber seal.) You can see that it slides all the way through the pipe that will become the piston bore.
Luka () Tue Nov 30 2010 09:34 PM Attachment	Re: Airgun take two
	Here is the piston started into it's bore.
Luka () Tue Nov 30 2010 09:41 PM Attachment	Re: Airgun take two
	The valve. Piston in the open position.
Luka () Tue Nov 30 2010 09:48 PM Attachment	Re: Airgun take two
	Piston closed. The seal here is just a washer from a plumbing repair kit. I am afraid it is not a large enough diameter. I may have to cut a better seal for it out of some of the red rubber you can get in small sheets, at Lowes.
Luka () Tue Dec 07 2010 04:43 PM Attachment	Re: Airgun take two
	Well, as usual, life ineterfered while I was making plans to continue this thread. I didn't get all the detailed pics I wanted. I've barely had time to get some small part of it done, every day. No time for pics. I did get this pic. It shows the valve pretty much together, and labels the parts used. But no chamber or barrel, yet. BTW: The grey pipe you see here, is actually rated to a higher pressure than standard sch40 PVC. 1" pipe comparison is: white sch40 PVC = 460PSI The grey stuff = 640PSI
Luka () Wed Dec 08 2010 01:45 PM Attachment	Re: Airgun take two
	Here is a pic of the pretty much finished airgun. It's a bit bigger than a pump shotgun. You can see that I took the grey 1" pipe and elbow off of it. I decided to try to keep the chamber as close to the barrel as possible. You also see a blue-handled ball valve on the barrel. That is a breech-loading device. It has a hole cut in the top side. When you "close" the ball valve, the hole in the ball, is exposed. Pack a piece of steel shot meant for a slingshot, into some toidy paper, then pack the whole thing into the ball valve. Then "Open" the ball valve, and yer ready to shoot. (Opening the valve, lines the hole in the ball, up with the barrel. Just as opening it when connected to plumbing, lets the water through.)
Luka () Wed Dec 08 2010 01:54 PM	Re: Airgun take two
	It will likely stay this way until I have a chance to test it. I'll put a bunch of steel shots through it. I'll also try darts. And at some point I'll probably make a more conventional looking breech, so that I can drop darts in, instead of having to muzzle-load them. Sometime this winter, I'll try to make a metal airgun. You can take a metal one to much higher pressures. To get those pressures, I'll probably have to convert a refigerator compressor over, to air compressor duty. They may be slow getting there, but some people have gotten them to pressures in excess of 1000 pounds.
Luka () Sun Dec 12 2010 12:10 AM	Re: Airgun take two *DELETED* *DELETED*
	Post deleted by Luka
Luka () Sun Dec 12 2010 12:23 AM	Re: Airgun take two
	The above airgun will put a 3/8" steel shot, halfway through an old, very tough, and soaked through and through, piece of 3/4" plywood. A double 'a' battery, wrapped in tape to make a snug fit in the barrel, will do the same damage. I am going to have to build a different kind of breech loader for the nail darts, because they get damaged when you try to muzzle load them. They have to be stuffed backward down the barrel.) I tried somehting a bit different, after the first few steel shot loads. I made sabots out of short pieces of wooden dowel, wrapped in tape for a very snug fit. Muzzle loaded one of those. Then a steel shot, wrapped in enough toidy paper, to keep the shot from just rolling around. This shot went deeper into the plywood, and left the hole stuffed with toidy paper. The wooden sabot hit about an inch away, and caused as much damage as the original steel shot tests. So, I'm going to look around for something to use as a barrel, that the steel shot will be a very snug fit in. And in the meantime, I am making a longer 1/2" barrel, a 3/4" barrel, and a 1" barrel. The common wisdom, when I asked, was that apparently a longer, -or- a larger barrel, will deliver more damage to the plywood, with the same steel shot. And at the same pressure. (With the steel shot properly sabboted, of course.) I'll glue the barrels up tonight. Maybe have time to test them tomorrow. I have been busy the past couple days, helping the neighbor with actual plumbing. LOL Putting in his water tank, pressure pump, etc. He may want me to help him on it again tomorrow and/or the next day.
Luka () Mon Dec 13 2010 05:02 PM Attachment	Re: Airgun take two
	What I was hoping for with this one inch valve, is "power", but keeping it as small a size as I can. My goal was to get a 3/8" steel shot through a tough old piece of 3/4" plywood that is soaked through and through. (Being saoked like that, makes it more difficult to get an object to penetrate. And it is a really tough piece of plywood, as well. Not like the newer stuff.) From about 35 feet away. Well, here is the pic of 'the damage', using a half inch barrel. The "short barrel" (2 feet) was used for the left shot, and for the AA battery. The steel shot only made it about halfway through the plywood. The AA battery went a tiny bit further, but caused more damage. The "long barrel" (3 feet) was used for the top shot. That one went a bit deeper, but not much.
Luka () Mon Dec 13 2010 05:14 PM Attachment	Re: Airgun take two
	And here is where I proved all your girlfriends wrong... Next, I am trying a 2 and a half foot long piece of 3/4" as a barrel. First I tried a glass marble. I had to 'sabot' that, because it is the same loose fit in the 3/4" barrel, as the 3/8" shot is in the 1/2" barrel. (The marbles will not even go into the half inch barrel.) I used two sheets of toidy paper. LOL Here is the pic of the damage the marble did. This marble would have gone all the way through the plywood, if the plywood hadn't been leaning against some metal. The marble just happened to hit where the plywood was maybe 3/4" away from the metal. The metal stopped the marble, (and the plywood ahead of it.), at that point. You can see the blue glass marble still embedded in the plywood, from the face.
Luka () Mon Dec 13 2010 05:24 PM Attachment	Re: Airgun take two
	The last damage pics. I decided to try a steel shot again. Even though it took THREE squares of toidy paper to sabot it. LOL This time, the steel shot went through the plywood. Not as cleanly as I would like, but it did go through. The steel shot did go all the way through. On the way, it tore a huge gash in the plywood. That gash is over 8 inches long. ~~~~~~~ I have been using the same homemade piston valve, the same chamber, and the same air pressure, for all of these shots. The only difference has been in the size of the barrel.
Luka () Mon Dec 13 2010 09:04 PM Attachment	Re: Airgun take two
	I might try the one inch barrel tomorrow. If I do, one of the shots will be a shotgun type shot. I stuck a pill bottle into a one inch pipe. Shoved in tight. Marked around it. Then cut it at the mark. It is filled with several of those 3/8" steel shots.
Luka () Mon Dec 20 2010 03:23 PM Attachment	Re: Airgun take two
	Ok, I may not have been posting, but I have been working on this. I started getting leakage through the piston valve. I had to rebuild the piston itself. But once done, it seals perfectly. No more leakage. I then put the one inch barrel on the gun and tried some shots. I like this combination. I think I'll use this as the basis for my finished gun. From this point it is a matter of looks, mostly. I will probably take a long time to finally get the looks and feel that I want. And has to be done in a way that doesn't affect operability. I haven't decided what look to go for yet. Possibly trying to copy one of the guns from the movie "district 9". Or possibly going with a steampunk look. Or who know what other direction I might take. Here is the bare basic gun with a one inch barrel on it.
Luka () Mon Dec 20 2010 03:53 PM Attachment	Re: Airgun take two
	Here are the first two shots I used. For one, I turned the pill bottle sabot upside down, and stuck a 3/8" steel shot to it using candle wax. For the other, I filled the pill bottle sabot with the steel shot, and wadded in the top with paper towel. In both cases, the pill bottle is what is called a sabot. If I was just using a wad of paper towel, behind the steel shot, with the shot loose in front of it, that is called a wad.
Luka () Mon Dec 20 2010 04:00 PM Attachment	Re: Airgun take two
	In both sabotted shots, the sabot was completely destroyed. I'll have to teach myself to make sabots from cardboard, or thick paper. I'll run out of pill boxes, soon enough. Here is what happened with the "shotgun" shot. All 9 of the shot were in that pill box "buckshot" type shot. The grouping is fairly good. That is about 4 and a half inches, not counting the one that went a bit more wild. None of them penetrated any further than any of the shots had, when they were shot from the 1/2" barrel. At least one of the steel shots went whizzing around, screaming, and richocetting off of stuff.
Luka () Mon Dec 20 2010 04:06 PM Attachment	Re: Airgun take two
	Here is the shot that was done with the single steel shot waxed onto the bottom of the pill bottle sabot. If you look real close, you can see the impression made by the bottom of the pill bottle sabot. The steel shot went completely through the plywood. Through a pipe that was about 4 feet behind it. Through a fiberglass window cover behind that. Through a window behind that. And through the wall of a cabinet, about 7 feet further on. You can also see he wax that was deposited on the face of the plywood. One last thing on this one... I do not have sights on the gun. So I was simply sighting down the barrel, the best I could. I was aiming at the knot. I think that was a pretty good indication of the accuracy of this thing.
Luka () Mon Dec 20 2010 04:14 PM Attachment	Re: Airgun take two
	Next up, a marble again. Simply wadded. I wadded paper towel up, behind it. But kept just one flap of the paper towel, to lay over the matble, before finishing by using the ramrod to get the whole thing down the barrel. That one small piece/flap was done simply to keep the marble from rolling around in the barrel. The marble also easily penetrated the plywood. It's mark is above and to the right of the steel shot mark. Both the steel shot and the marble made entry holes that are as clean as is possible with wet plywood. They made a bit more damage coming out the back. You'll see that pic in a bit.
Luka () Mon Dec 20 2010 04:21 PM Attachment	Re: Airgun take two
	After shooting the wadded marble, I wondered what would happen if I shot my ramrod instead. (42 inches of 3/4" dowel rod.) I stuffed the same wad down the barrel. (This wadding is made of a kind of paper towel that is a lot like a piece of cloth. The wadding is still useable, after you use it to make a shot.) Here is what happened when I shot the ramrod. Note, the blue marble that I shot from the 3/4" barrel the other day, is still stuck in the plywood, below the ramrod. There was quite a bit of "kick" from the gun, when I shot this.
Luka () Mon Dec 20 2010 04:25 PM Attachment	Re: Airgun take two
	Now, the pic from the side, with the ramrod. You can see that it penetrated by more than 12". I actually aimed for the same area as the earlier two shots with steel and marble. But this went flying off the mark, to the left. In this pic, I am shooting the pic from the right side of the plywood. The rod itself is in the distance.
Luka () Mon Dec 20 2010 04:28 PM Attachment	Re: Airgun take two
	And now, the pic from the back of the plywood. One thing that I don't like about pictures is that everything gets foreshortened. The damage is labeled.

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