Well, this is my first post that has any sort of mod/integration in it, so here goes.
Dremel (cutting wheel and a cutting burr smaller than the vinyl tubing you are using) AT2K (preferably with shell) 1/4" OD Vinyl tubing. (Home Depot) Plumber's Goop (or other adhesive) (lowe's / K-Mart) 3"x1.75" Plastic sheet (thickness doesn't matter, just make sure it isn't flimsy) 2' of your preferred barrel material (I used brass) Hobby Knife
Start with your pump, break off the nipple that holds the tubing on it, it should break rather easily. It looks like this when done:
Then, with your cutting burr, drill the existing hole where the nipple was, use your tubing every few seconds to make sure the hole doesn't get too big, the fit should be tight, and make sure you can push the tubing in so you get a nice seal.
Once you've done that, goop up the tubing and the hole and slide it in, you can use the pump to flow some air through it to make sure that you haven't gooped the valve.
I put mine in far, this reduces airflow a tiny bit.
Put that aside to dry and get out your AT Tank, cut at the green line (on the pic), and using another piece of tubing use the same sizing procedure as you did with the pump. Be very careful, I made sure I blew all of the plastic pieces out of the tank. Remember, you can always make a smaller hole larger, but you can't make a larger hole smaller.
You can disregard the blue tape on the front, this is another tank I have and I am using it to illustrate where to cut.
Ok, now that our tank is done (DO NOT GLUE THE TUBING IN YET) we can goop it onto the plastic. In reality you can really use any sort of sheeting that is 3"x1.75" but the plastic was the best option for me, and would fare better than metal or wood. Anything that lifts the tank up enough so it doesnt hit the front hand portion of the BBB will be fine.
I sanded down the surfaces that the tank was going on, and if you want you can use a dremel to make the surface rougher (more surface area = stronger bond) but I just used sandpaper on the tank and the dremel cutting wheel on the surface. You can make small channels by going at a slow speed and grinding across the surface of your 3"x1.75" sheet.
Glue the tank on the straight edge of your surface like this, the green is whatever sheeting you're using. This would be from the side of the tank. Use a rubber band to secure it as your goop dries.
Once this was dry, I sanded the surfaces of my BBB that touched the plastic when I set it in place on the front grip. In this video you can see how I positioned my plastic. NOTE: This MUST be on the side of the BBB with no screws. If you want it on the other side I suggest you drill holes and make sure they don't get filled in when gooping (plastic straws would work nicely).
I applied liberal amounts of goop where it touches the larger main cylinder of the BBB, and again let it dry. (make sure goop doesn't flow down and seal the two halves together, or else you'll have a hard time opening your BBB again).
Don't worry when you see the pump, it's not supposed to be there yet.
Once the goop had dried, I used a dremel to cut out the plastic that was going over the edges of the forward grip, and the part that went over the curve on the bottom.
Now, you are ready to add the pump. Sand down the pump so that it's surface is rough, and sand down the area at the top where the pump will be going, look at the pictures and video for reference on how to position it. Then, goop the surfaces and apply a rubber band around the pump so that it will dry in place. Let the gun dry vertically (how you would hold it) so that goop does not seep through the small interstices underneath the small upper cylinder. Let this dry.
Now, get the two plastic shells of the AT2K and cut the front part that makes a + sign out:
Cut at the green line, and get this part from both halves of your shell.
Now, position those two pieces on the pump front and use any adhesive to glue it in place. If they don't fit, use the dremel to trim the pieces so they fit. I used hot glue since that can be removed more easily than other options (if pump handle breaks etc.)
Then, after those have been put in place, cut your tubing to the length you want (make sure it reaches the tank) and then using your goop put some over the tank opening and then some around the tube and slide it in as far as you choose, I don't know how far mine went in, but it's pretty stable. Pump some air through the system to make sure that you haven't clogged anything.
Let this dry.
Once this part is done, your BBB should look like this (sans my aluminum barrel).
Now we are ready to add the turret. I will tell you how to do this part as it can be done with whatever barrel material you want, all you need to do is cut the front off around the line near the bottom of the barrels, take out the AR's, widen the openings if you want, and glue in your barrels.
I used 4x 6" 9/16 OD K&S Brass for my barrels, however please choose whatever is best for your darts.
Once this is completed, using your goop, goop the turret on to the front part of the tank, and then also at the plastic where it will touch. It should look akin to this:
The rubber band there is to hold it in place for the picture, as I hadn't glued that on yet.
When it is drying I suggest leaning it against a wall so that it stays aligned. As for the trigger, you can use whichever system best fits you, I leave this open ended.
When that is done you will have a greater primary.
Here's my final product:
The PVC and brass you see on the rear of the tank is my trigger system. The trigger pin was wrapped in E-Tape until it had a snug fit inside the spare bit of 9/16 brass, then glued in. The PVC (1/2") was then trimmed and cut so it could be gooped to the bottom of the tank, which provided a guiding for the trigger pin. then I used Epoxy Putty to support the PVC at it's other end, resulting in an extremely sturdy mount. My reasoning for this is that w/o of any support or guiding I was likely to bend or twist or injure the tank in some way, so that provided security, the turret is set in place with goop and epoxy putty. All in all, it turned out great.
And yes, you can do this to both halves of the gun, just make sure to drill holes in your base for the screws if you want to keep the BBB shells seperate for fixing.
In case anyone asks, I have done the following mods to the BBB: Spring Replacement (that one from home depot) 12" Aluminum Barrel with washer on the end cap of the plunger assembly to keep darts from falling in, and all dead space has been removed to the best of my ability. The two top annoying things have been sawed off. I added extra springs to both the trigger and the catch plate I added two layers of Foam Rubber to the 'wings' of the punger rod where the tube impacts after firing, still is loud as hell but at least it won't destroy itself.
No, I do not have ranges nor will I any time soon. (Accuracy > Range anyway).
If you have any questions at all or would like some pictures of something, feel free to ask.