Buzz Bee Big Blast that packs a punch.

Today I will be doing a write-up to build your very own Buzz Bee Big Blast with an integrated Airtech 2000, with a shared stock pump. The point of this project is to install a secondary air chamber into the internals of this toy, so that some of the air from the main pump is redirected to the smaller tank. One reason for this is so that their is a lower air pressure in the large air tank, meaning the foam darts hurt less if shot out of that tank’s barrel. Also, the secondary air chamber means a nerf player has a backup shot ready at any point, for situations where they are caught reloading the primary barrel.

Materials needed:

  • 3/4″ to 1/2″ PVC slip fitting
  • 1/2” PVC coupler
  • Polycarbonate in varying sizes
  • Various hardware
  • Goop, Gorilla glue, and Solvent weld
  • Polyester Resin – optional but recommended
  • Vinyl tubing- 1/4” OD 1/8” ID
  • Super Soaker Shot Blast pump., or any check valve that will fit
  • Brass tubing connectors

Step 1. Get your Big Blast

Remove the Orange Ring

And open it up

Step 2. Find the section of plastic on the side of the tank (See pic)

And remove it

And then remove the stock barrel

Step 3. Get a 3/4″ to 1/2″ PVC slip fitting

And then sand the 3/4” side till it fits the end of the tank

Apply solvent weld to the tank and bushing and let it dry, be sure to do so in a well ventilated location, preferably outside

Step 4. Find the middle wall where the tank/barrel goes (see pic)

And trim it down, repeat for the other side of the shell

Make sure your tank fits in place nicely

Step 5. Now minimize the shell

Then you will need to widen out the hole for your PVC barrel.

You could stop here and have a great simple and clean primary

But part 2 of this mod is integrating an Airtech 2000 tank

Part 2, step 1. Get a 2k tank, and glue it to a pvc coupler that is cut down so it rests snuggly in the tank

Line up where you want the tank’s coupler to be on the gun

And cut a hole for the PVC barrel

Step 2. Next you will need to machine a trigger

Then line up where the pin would go in this trigger. and cut it to fit- also cut a notch in the shell for the trigger pin

Step 2 Continued. Then you will need to screw a side-plate on both sides of the triggerStep 3. To hold the tank in place, I poured a Polyester resin into the shell, making sure to cover the tank to protect it. You can get this resin at a local craft store, I will explain it further in a future topic

If you have any resin left over, go ahead and reinforce the shell

Now all that’s left is to link the air lines!

Step 4:The pickup line for the 2k needs to be close to the base of the pump tube, to
receive a full “stroke” of air each pump.
That’s where you’ll drill the hole for 1/4″ OD tubing. Clean up any debris that might find its way into the pump tube. Crumbs of plastic will destroy your pump’s oring quickly.

I followed my usual routine of tacking the tubing in place with super glue(I
use Gorilla brand exclusively), then following-up with some Oatey’s red can
PVC/CPVC/ABS cement. Goop could be an alternative sealing method, but I hate
the long cure time and the solvent in PVC cement will “weld” the tubing in

Step 5:
While that assembly cures, use the same process to attach tubing to the 2k tank. Add a narrow diameter spring to the tubing here, to prevent pinching of the line when bent. Pinched lines won’t allow air into the tank efficiently.

Here’s the check valve in place on the line from the pump tube. The check valve is necessary to prevent both tanks from emptying each time you fire one. In this particular case, the 4B has a check valve in the base of the pump tube, so we only need to add one to the 2k’s input line. Obviously you want the valve’s flow oriented into the tank.

Step 6:
A little creative routing gets the tubing from the 2k tank to the rear of the shell. Drill a hole through the bulkheads, larger than the tubing to allow movement. Debur the holes to prevent unnecessary chafing. Be sure that no lines are pinched, and that no lines impede movement of the trigger assembly.

And finally, all linked up.

This setup is efficient, but doesn’t provide “lethal” pressures to the 2k tank; so it’s a great backup or “mercy” shot rather than launching a full-bore 4B shot to someone point blank.

Final picture!

Mattel Ultimator with enhanced inner workings.

This is the Mattel Ultimator, circa 1994. It features a rather large and space wasting extension spring as a power source. To me, that just seemed silly, as far as critiques for a foam missile launcher can be silly that is. So like any modder aficionado, I sought to make it better, and documented the build log so others could follow my steps.

To begin, naturally, find yourself a Mattel Ultimator and dive in.

Mattel Ultimator unmodified

Now open it up, take extreme note of all the small pieces, and marvel at how ingenius its design truly is.

Step 2. Take the barrel and spring and put them aside

Step 3. Order a 1’ section of 2.5” ID 2.75” OD Polycarbonate tubing, a pack of K14 springs, and a 2” to 1/2” PVC reducing bushing from McmasterCarr

Step 4. Slap a large metal washer in front of the priming-mech to protect the plastic (Ignore the k26 spring)

Then go ahead and slide on a cut down K14 spring and bolt the plunger head back on

Step 5. Machining the Plunger tube. This is where it gets tricky and people have asked me to do it for them.

First, cut a slot on the top and bottom of the plunger tube, using the stock one as a guide. I did this using my Band-saw.

The slots were 1.25” wide, on both sides, and went down about 1.75” Then you will need to line up the plunger tube for the 2 holes on each side that secure the plunger tube to the gun

And drill them out with a 3/8” drill bit

I screwed this part up a bit and had to widen the holes.

Step 6. Assemble the gun. Tape the bushing, bolt it in, liberally apply some amazing goop to keep the air loss to a minimum, and slap a hopper clip on it.

You know have a Mattel Ultimator that is much more optimized for firing the traditional homemade nerf darts. The dead space of the large orange barrel is now a thing of the past! Congratulate yourself and go play with your cool new toy.

Alternatively, however, you can keep the stock spring, and just use the clear plunger tube for a striking visual effect

For those of you that are curious, this is how the Ultimator catch system works:

It’s essentially a large caulking gun made with parts from Ace.

Issues with this mod:

The Ultimator was able to send a dart 115’ in about 8-10 pumps of the cocking mechanism, however I came across the issue of the plunger rod gradually slipping forward. I’m sure this is a result of lubricant from the plunger coming into contact with the friction based catch mechanism, if this happens to you too, it should dry out eventually to solve the problem.

Mcmaster-Carr #s:
Plunger tube- 8585K341 1 Ft.
Polycarbonate Round Tube, 2-3/4″ Od, 2-1/2″ Id, 1′ Length
Clear Plunger Tube Bushing- 4880K172 1 Each Std-wall (schedule 40) White Pvc Pipe Fitting, 2″ X 1/2″, Hex Bushing, Pipe End Male X Socket F
K14 Springs- 9637K14 1 Pack Continuous-length Compression Spring, Spring-tempered Stl, 11″ L, 1.093″ Od, .105″ Wire

Thanks for reading as always, feel free to post comments, questions, or concerns.