My kitty destroyed a months worth of work on my thumb drive this morning, so my plans to work on something a little more original got slammed to a halt. So I decided what better time to finally get started on my mechanical Aedes project. I shared a tiny bit about it in new ion's thread about his project, but I'll go into a lot more detail here as it progresses.
The gun is retrofitted into a Spyder body. If you haven't noticed by now, I like to put new systems into existing bodies because it is a hell of a lot faster and cheaper than building a new body. Can't be an all bad idea, look how far Intimidators have come....
Despite what most people have thought, and what I have even claimed myself, it is possible to get an Aedes style system into a Spyder body. There is no reason that the air transfer port between the tubes needs to be completely behind the bolt from the start, as long as there is enough of an overlap that air can get behind the bolt to start it forward.
I got the drive train done today, I'm hoping to get the valve done some time this weekend as well. It's near identical in function to the valve in my closed bolt Ion, but instead of an inline power tube, it takes a left at Albuquerque and goes to the top tube.
I tried making an aluminum linkage, but it turned out pretty ****ty, so I just turned down the head of a 3" 10-32 machine screw, and cut it to length. Wish I had just done that to begin with. I also just used a nut instead of making a new spring stop. With the flat faces on the nut, and the slot in the front of the linkage, I can just stick something next to the nut, and use a screwdriver on the front of the linkage face to adjust the valve throw - no special tools required.
The little conical piece is dual purpose - it helps reduce a bit of wobble in the system by locking the linkage into the bolt, and it eliminates the flat face between the ports in the bolt.
The middle o-ring groove is for a bolt bumper for the return stroke.
Got part of the PCP valve done today - the spacer and one of the 2 valve bodies (the one the firing seal is made at). Took me a lot longer than I would have liked, boring almost 4" deep accurately on a 9x19 lathe takes a lot of patience, let alone getting a bore that is smooth enough to make a good seal. The spacer is somewhat multi-purpose. It holds the 2 valve components a set distance apart, but it also holds the pressure of the dump chamber. The design I'm running with has the valve in the back half of the gun instead of the front, and with all of the slots in the back half of a Spyder, something needs to be done.
The piston and rear valve body are hopefully tomorrow.
Got the rest of the valve done this morning. 2 shots on the piston, the first one I made last night had too small a lip that stops the forward movement, and it lodged itself into the valve. I've decided to just use screws to hold the valve and bolt assemblies into the body, the body is tapped for 10-32 screws and the assembly units have 3/16" holes that capture the machine screws and lock them in place.
Lower tube assembly. Uses the standard poppet valve retaining screw at the front, and a 10-32 machine screw to lock in the back end.
Now the similarities to my closed bolt Ion valve become a bit more apparent.
Piston retracted as if it were firing.
Piston forward as if it were filling the dump chamber
So I got it firing this afternoon. I have 2 normally closed valves running through a tee to the back port. Open the first valve, and the piston moves forward, sealing the valve and filling the chamber. Release the button, and it stays pressurized (pending leaks). Push the second valve, and the chamber behind the piston vents, forcing the piston rearwards. This isolates the supply air from the dump chamber and opens the main valve seal.
Of course, like many of my prototypes, I get off half a dozen shots before breaking it. I knew there was a reason I hadn't just used a nut when I designed the bolt assembly, I had the spring stop act as the bolt movement stop just like Colin did with the Aedes. I had set it up to stop upon full compression in the build though. A few solid shots, and my spring was toasted. I need to hit the hardware store, hopefully tomorrow, and grab a few more of the springs. I made a shim stop that goes between the spring and the nut that will make a positive stop against an inner lip of the bolt carrier, but I need to replace the spring before I see how effective it is.