I know this is an old thread, but I don't check back often enough...anyway, if your still interested in the hammer assembly its very easy to make, and without any machining experience mind you. you can get all of this stuff at a hardware store for about $10 (except clipard QEV), and then spend about 4 hours (exaggeration) assembling and tuning it to work properly. Also not that I can do this for a halfblock, a full block will need to rout the QEV through the bottom of the body, but its a similar build)
parts:
-standard hammer
-threaded 10/32 shaft (has to be cut to final length, as I am not sure of exact length off the top of my head, and I have it all epoxied together as a precaution to prevent any drop off in velocity due to an unscrewing hammer)
-a 1/2 inch aluminum spacer, threaded for 10/32
-3 nylon spacers of 3/8 inch outer diameter, threaded 10/32
-2 o rings that has an outer diameter of 3/8
-Clipard QEV (it has to be clipard as it has the proper input setup with a small area where it has no threads, allowing it to go into the ivg farther...an SP QEV may also work...)
-3/8 ID aluminum tubing for ram tube (should polish it when finally cut to length, and debured)
-a steel spacer that has a 1/2 inch ID so the assembly doesn't wobble in the body, and cause inconsistencies.
-conical spring for a return spring.
-a good valve spring kit (you will use the lightest spring for sure, unless your going mech, then you may use the medium, and run the gun at mid to high pressure=efficiency)
in order to properly build this ram, the above parts are needed (QEV is optional, but makes a HUGE difference in shot to shot consistency)
setps to build:
1. Remove all gas from marker, and disassemble the entire lower tube...
2. Begin with the hammer, cut off the back ring on which the hammer spring sits inside of
3. Thread the rod all the way in the hammer till it goes in no more, this way you have a base in which to attach you hammer, and build the rest of the ram.
4. Thread on the aluminum spacer
5. Take 2 nylon spacers and make a small bevel on one edge of the spacer, the bevel should be around a 1/4 of the way down the side wall of the spacer. This acts as an oring adjustment, so you can adjust how tightly the oring slides in the ram tube, giving you maximum performance, and no hammer stick.
6. Thread on one spacer with the bevel facing away from the hammer, and slide on the oring, if it sits on the bottom of the bevel, or not at all (you can use a smaller than 3/8 diameter if you wish, but thats what I recommend as its easier to install) then thread on the other nylon spacer with the bevel towards the oring.
7. Thread the spacers up so that they both touch the oring, slowly twist the top spacer until the oring is in a makeshift "oring grove grove" created by the bevels. Note there should be a small space between the spacers, unless you cut your bevel too deep, this allows for some adjustment of the oring stretch when you finally get the tube cut to length, and will also adjust the friction it will put on the lower ram tube.
8. The end of the second spacer is now the point where you need to cut off the threaded rod, this is your hammer assembly.
9. Next you will need to cut an oring grove in the remaining nylon spacer, this is the seal in the back of the ram tube, and allows the QEV to attach directly to the ram, rather than go through a short manifold.
10. Drill FROM THE INSIDE of your IVG with a 1/2 inch drill bit, to recess the ram tube into the IVG. this is not to be drilled all the way through, this is just in about 1/8 of an inch on the walls, so the tube has more stability in the bottom of your gun. (avoid this step if your not using a QEV, as its not really needed, if you are going to use a standard barb...proceed to step 15 )
11. Next take your QEV and figure out what drill bit size the short area that is not threaded, but not into the body of the valve, this is the size you will need to drill out the allen hole to accept the QEV, and drill this all the way through.
12. Check to see if your counter sink hold drilled with teh 1/2 inch bit is deep enough by comparing the remaining metal on the IVG, if the QEV can go through but not all the threads are showing and are able to be threaded onto the nylon spacer, drill it slightly deeper, until the QEV is able to seal against the spacer.
13. Drill 4 small holes on opposite sides of the outer face of the IVG so you can use a pair of split ring pliers to thread it into the body.
14. Thread the spacer onto the QEV, with your IVG in the center of it all. thread this in the body with a pair of split ring pliers as stated, adjust the position of the IVG as shown, so it points down.
15. Lay the hammer assembly next to the aluminum tube on a flat surface, eyeball about 1/2 inch from the factory cut end of the aluminum tube (its cut straight, and only needs to be deburred) to the back of the hammer, and mark this length. cut off the tube and debur it with a round file. slightly rounding out the openings is also beneficial to the ram when assembling.
16. Slide your hammer assembly in one end of the newly cut off ram tube, and insert the nylon spacer (removed from the IVG setup for now) and see how far in it rests with the hammer back as far as possible, if its 1/8 inch or less, leave it at that, and go on to the next step, if its longer you need to cut it off so its 1/8 or a little less. if its shorter than the spacer is tall, that may be ok, as long as the oring has about 1/8 inch to seal inside of the tube, you will be fine, if its shorter than that, recut a new one.
17. Inspect the steel spacer, file down the inner weld point if needed, as it can dent your ram tube making your work of getting it the right length completely wasted, and you will have to make another one. once the weld point is flat and smooth on the inside of the steel spacer, slide it over the ram tube, it should be slightly snug, if its not, slightly smash it in a vice, or with pliers, and when I say slightly, I mean so slightly that it is not even noticeable, just so it holds on the ram tube securely, and rests in the center so some ram tube is showing on either side of the spacer.
18. Polish out the inner bore of the ram tube.
19. Lube throughly with grease, and assemble the ram kit completely. if the hammer portion of the ram slides fairly rough, or its very stiff, pull it out of the tube, and back off the back nylon spacer to alleviate some of the pressure it exerts on the ram tube, but still has enough pressure to seal and slide very smoothly.
20. Replace the valve with the lightest spring in the kit you have.
21. Drop the conical spring into the lower tube, so that the small side is down. you want the small side to go over the valve stem so that when the hammer comes forward its able to hit the valve stem.
22. Install the hammer kit as a unit, making sure that the conical spring exerts a small amount of pressure on the hammer at all times, very small amount of pressure (you want the spring as light as possible and still return the hammer, as this will allow you to tune the valve easier)
23. Attach the qev to a second 3way, or to an electronically controlled noid, and air up the gun (once you get all of the hose routing and 3way mounting sorted out.
24. When firing for the first time, it should either not open the valve at all, or very little. you will want to up the hammer LPR until the noid leaks (if electro) or up it so you see fit on a mech (mech pressure should be around 80 PSI in the hammer)
25. Now set the HPR, on a mech set it high enough to fire a ball, and stop venting air out of the valve when the trigger is held. mech users may need to change to the medium spring.
26. Enjoy your osiris moded cocker, it took a while to build, but its definatly worth it to have a walkable mech or a super smooth electro that happens to shoot around 30 shots a second...
BTW, this works with mechs, but you have to very carefully regulate input pressure to the ram, input pressure to fire the gun, and valve spring pressure. most guns work fine at the lowest spring strength, 70-80 PSI in the hammer and around 400 PSI on the HPR at 300 FPS...just takes some tuning.
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