I'm really happy with this mod, I had to go through a bunch of iterations to get the triggering to work right, but now that it does it's a pretty sweet gun.
Here's the stock Big Blast and Dart Tag Blaster, the BB is really sort of hideous, and the DTB is pathetically under powered.
So what do you get when you combine the power of a BB with the versatility of a 10-shot turret?
The DTB+BB! Yes, I know, the name sucks. Maybe the Big Turret Blaster or something. I don't know, either way, it's a pretty slick gun.
Here's your stock Dart Tag Blaster, the first step is to open this sadly under-rated gun up.
Here's the internals of the DTB, we're going to be gutting out the air plunger mechanism and leaving only the turret advancement mechanism in place.
You'll want to keep the very tip of the air plunger to attach to the big blast's barrel for a good air seal on the turret.
This is the back of the turret for the DTB, it's a real quick and easy disassembly. Remove the 4 screws attaching the orange part to the black part and it comes right off.
At this point if you're going to follow along with me, just discard the orange part, or hold on to it for future use in some odd gun that you dream up. I'll be attaching PETG directly to the black back-plane of the turret.
If you're not going to do CPVC or PETG, just remove the stock air restrictors and drill out the barrels, then put the turret back together.
Here's your stripped down DTB, make sure you remember where everything goes, the advancing mechanism in this gun is simple, but really really picky.
I also wanted to remove the "Clutch" from my turret, so I unscrewed the single screw holding the two parts of the advancing gear together and glued them together before replacing the screw.
If you're going to be doing CPVC or PETG, turn the turret over and dremel down the edges around the holes, they're not quite large enough to fit PETG inside them, and not quite small enough to fit PETG over them. In other words they're a pain. Just get rid of em.
Now to do this mod, I disassembled the Big Blast and laid it in the DTB shell without the turret in place in order to measure where to cut off the barrel so that I could add on the tip from the DTB. I ended up cutting off about 2.5" of barrel, but measure for yourself so you dont end up cutting too much off.
I also took the dremel to the DTB's shell and cut it so that the BB's chamber would fit.
After measuring, cutting and epoxying the tip from the DTB onto the BB's barrel, I put the stock BB shell back on and measured where to cut so that it would butt up against the DTB's shell. It ended up being a little bit in front of the BB's grip/trigger, so I cut the BB there and fitted the shell in place. This left the tank and some of the firing mechanism of the BB exposed, but I'll address that in a bit.
I added a small ring of FBR to the front of the barrel in order to insure a good seal between the barrel and the turret, the stock setup was woefully lacking in a good seal.
Here's the turret half-completed, I used Zap-A-Gap super glue to put these barrels in place and will fill in the gaps with hot glue to insure a good seal.
This is the turret with all the barrels in place, they look all nice now, sadly sometime overnight while I let this mess dry, they went all cockeyed. I'll fix it later, but as you'll see in the distance tests at the end of this guide, it doesn't really make a difference.
Originally I tried to stick with the stock triggering mechanism for the BB, but I quickly discovered that with over 5 pumps, the BB became incredibly difficult to trigger, making the plastic piece that was originally provided utterly useless.
As a side note, I also had to plug the overpressure valve on the BB's plunger, but that's just a standard "Hot Glue in the End" style job, and I completely forgot to take a picture of it.
Here you have the beginning of what ended up being a truly successful use of materials on hand.
The wire is the trigger pull from a Hornet (I have 2 dead hornets, so I can spare it) that I bent into shape. I added a U shaped bend so that the wire would catch the release pin, and then bent it in half near the trigger so that it would have a nice catch surface.
A view from below, you can see how the U shaped bend hooks over the pin.
Here's the original trigger pull piece for comparison, it's simply not strong enough to pull the pin back under a great deal of pressure.
To attach the top, I went cheap and hot glued the thing to within an inch of its tiny little life. I put a spare piece from the DTB shell under to make sure the glue didn't just drip off.
The trigger pull wasn't quite hard enough to yank the pin back, so I added a piece from the original BB trigger to extend it back a little bit.
The hot glue on the top actually impeded the return of the wire to the original location so I added a spring that was spare from another modification and hot glued it into place to push the wire back forward after the trigger returns to the forward position.
The view of the completed triggering mechanism from the side. I painted a bit before I added the front of the BB shell to the gun.
Here's your completed BB+DTB gun, as you can see, I cut a piece from the front of the original BB shell and used it to cover over the exposed portion of the BB's tank and firing mechanism. I hotglued the two pieces in place, making sure that the glue was only on the DTB shell, this way I can still take the gun apart if needed. The front part of the BB shell just comes up along with the DTB shell.
You can see here how the barrels got cockeyed, but for all that they're a little crooked, they still produce a really shockingly close pattern. I was expecting a couple darts to go off sideways or something but everything landed in a pretty close line to where I was shooting.
A view from the rear, I really sort of hate the BB's giant handle for the plunger but I don't have a good solution as to what to do about it so I left it alone.
Preparing to prime the DTB+BB here along with all the attachments for my modified Titan.
I primed it in gloss black, and after that I couldn't really decide what to do with it, so I went back to my Firefly and Titan painting projects to give myself a little time to think.
Here's the completed gun with 4 coats of black gloss and 3 coats of gloss clear coat.
I decided to leave the gun gloss black mainly because I think it looks really slick like this and because I have no idea what else to do with it at this point. I can always revisit it later.
And here's the gun in its place on my arsenal wall with the FireFly.
Distances when shot flat, 2 sets of 10 shots, 10 pumps per shot, rounded down to the nearest foot:
45, 44, 42, 42, 40, 38, 38, 38, 37, 33
46, 43, 43, 41, 41, 40, 38, 37, 37, 35
Not too bad for a turret gun. Although I don't really know what I could get out of this in an absolute sense, so that
could be complete junk and I wouldn't know it.
Hope you enjoyed the guide, I will be adding the disassembly steps for the Big Blast after I actually take pictures of one, I had the BB disassembled already before I decided to do this mod, so I'll get those pictures up in a couple days once I get around to disassembling my other BB.
Suggestions and constructive criticisms are always welcome, as well as questions.
You can find my Flickr based guides and a bunch of pictures here:
Nerf Pictures and Writeups
