Boom Toob

A new version of the Boom Toob is available!

This is the Boom Toob Two (Boom Twoob?). It is very similar to the first iteration, but with a number of improvements, the most important of which being its polycarbonate plunger tube, which is better in every way than PVC, and compatibility with silly shells, which enables compatibility with many other shotgun-style blasters, and virtually all dart types.

The adapter for the original, custom shells from the original Boom Toob is still compatible, as are all the custom shells.

FPS Numbers (when tuned properly):

Six short darts (silly shell): upper 80s

Six short darts (custom shell): low to mid 90s

Triple mega: upper 70s

MXL (custom): 103

MXL (silly shell): 90

Hardware:

Lots of M3 screws and nuts (six of these nuts should be locknuts. More on that later)

One M4 screw and nut

4 M2 screws and nuts

K26

2mm craft foam (for seal)

Something rubber to use as plunger padding (dart tips, bits of rubber, o-ring) (I don't recommend using foam)

Superglue

2.5 mm elastic cord

Specialized hardware:

Impact-Resistant Polycarbonate Round Tube, 1/16" Wall Thickness, 2" Od, 1-7/8" Id, 1 Foot Long

8585K27

Oil-Resistant Buna-N O-Ring, 3.5 Mm Wide, 40.7 Mm Id

1302N62

Assembly tips:

Use locknuts on the barrel pivot screws to prevent your nuts from popping out over time

Use locknuts for the plunger cap screws, and loosen them slightly so that you can fit a razor blade between it and the main body. This will allow the plunger tube to push forward when firing. Although this step is not necessary, it will improve the seal and performance. 

Use lots of lube. Slug Slym Tube Lube works very well.

Certain moving parts might require sanding to work smoothly. Sand as needed.

Included in the files is a plunger tube cutting guide. Slide the tube into the main body, then place the guide around the tube. This should make cutting easier. I have no idea what the correct way to cut PC tubing is, but I used a utility knife (DEFINITELY not the correct way).

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Original Boom Toob:

Update 3: Added a new version of the plunger cap with stronger reinforcements and a tighter central hole for a slightly better seal.

Update 2: Reinforced several weak points of the Main Body Back to improve longevity. Added plunger rod V2 with metal threading.

Update 1: added plungerhead v2. It should help prevent the blaster from ‘eating’ o-rings as it did previously (o-rings used to wear out very fast and were often pulled out of place). In addition, it has a slightly better seal and less of a tendency to twist during assembly.

This is the Boom Toob. It is a compact, yet powerful nerf shotgun designed to be used as a specialty secondary blaster, and, as such, can fit in large holsters. It is roughly the size of a Mega Magnus. It can fire anything you can fit in the barrel. Currently, I have designed shells that can fire six short darts simultaneously, three mega darts simultaneously, or one mega XL dart.

Whether you want as much power as you can fit into a sidearm, or are just plain tired of aiming, it has a place in any arsenal. It can even be used as artillery to rain darts from above.

Designed to use a 1.5 in PVC pipe as its plunger and a K25 or k26 as its main spring, it has more than enough power to fire almost anything effectively.

Required hardware:

(All screws must be countersunk machine screws. All screws should ideally be Allen wrench compatible because some spaces are tight, and using a screwdriver may be difficult, but not impossible.)

6X M3x8 screw

10X M3x16 screw

2X M3x12 screw

4X M2x12 screw

1X M4x20 screw

Every screw needs a corresponding nut, except for the M4 screw, which threads directly into plastic. Unless, that is, you use the plunger rod V2

A roughly 125 mm length of 1.5 in ID PVC pipe (you will need to shave it slightly for exact fit)

2.5 mm elastic bungee cord (you can use rubber bands instead, but they will wear quickly)

K25 or k26 spring

2mm craft foam for air seal

Use old dart heads for plunger head padding, as the foam plunger head padding tends to wear out quicker and cause failures (in my experience)

3 springs that are roughly 9-10 mm in diameter and 36-37 mm long (you may be able to scavenge these from household soap pumps)

1 size 126 O-ring

Tools and supplies:

CA glue

o-ring safe lube

Allen wrenches or screwdrivers

sandpaper

knife

hot glue or some kind of putty-like adhesive

Printing:

Some parts may be difficult to print without a good machine. all parts except for the plunger rod, catch, trigger, and plunger head require at least some supports.

Post processing:

some parts will need to be sanded and lubed to work properly, depending on how precise your printer is, this may include the catch, trigger, and inside of the grip where the trigger slides.

Assembly:

If it looks like it goes together, it probably does.

If your nuts are loose, try adding glue to it, then pulling it into the socket with a screw from the other side.

The breech requires two springs to open. The one in the front will remain full size, and pop into the two opposing holes. Hot glue the spring for the rear hole, and ensure it lines up properly with the breech as you close it. Trim the spring as necessary to allow full closure of the breech. This spring does not need to be very long.

The barrel release and the catch both use elastic instead of springs.

There are hooks in the barrel release and the end of the barrel to allow you to use elastic to hold the barrel open (but you still will need a spring in the back to overcome the friction from the seal)

This blaster loves lube. Do not be stingy with it.

Other notes:

As with other high-power nerf blasters, do not dry-fire. I did that once accidentally, and the plunger cap exploded.

The shell adapter has a tight friction fit, as well as a grove to allow it to twist into place. If your machine struggles with tolerances, you will likely have some sanding to do.

It is highly recommended to use locknuts for the breech pivot. The repeated opening and closing tends to cause standard nuts to shake loose.

If you remix or modify this (which I encourage), post a link in the comments, I wanna see the cool stuff you do with this platform!