Recently, i've been modding a few blasters which came in single barrel designs, they have great performance but with all the new blasters available nowadays with much higher ammo capacity and RoF, single barrel blasters tend to be at a slight disadvantage in Nerf games, so i resumed working on modular PVC turret designs to further improve the effectiveness of those single barrel blasters.
Some modders may have also seen the excellent 8-shot turrets made by SorrowX in this forum, he used a 3D printer to create his turret parts and the result is nicely made parts... though unfortunately the parts creation process itself is largely inaccessible to most of us modders.
My modular turret design aims to achieve a similar goal, except that it does not require a 3D printer, just PVC pipes and epoxy glue.
Here is the process...
These are the basic materials and tools that you'll need.
- 13mm / 16mm / 20mm SingaPlastics PVC Pipes (Thinwall Versions)
- 1/2" PETG Tubes (.528" ID / .572" OD)
- 2-Part Epoxy Glue (I use Selleys Super Strong Epoxy Glue)
- Pipe Cutter
Note that all the pipes and tubes i use are able to nest within each other. This turret design is built around those material specifications.
Its also possible to make this turret with non-nesting pipes and tubes too, you'll just have to adapt the parts to fit and align with each other.
We will start with the barrel spacers first.
For each barrel spacer, cut 8 x 1cm length 13mm PVC pipe and 1 x 1cm length 20mm PVC pipe. Ensure that the cuts are even and matching, avoid making angled or uneven cuts.
Use the pipe cutter's reaming tool or a hobby knife to trim off any sharp bits sticking out, so that the barrel spacer ports have a smooth surface.
Position the smaller pipe rings in a balanced circle around the central large pipe ring, then fill the space in between with epoxy glue. Constantly make sure that the parts are all aligned properly.
I did the gluing process in stages. The glue is applied in successive layers, each time the glue is properly cured for a few hours before the next layer is applied. After 3-4 layers, the space will be filled in nicely and forms a very tough bond between the parts.
Do this twice to create 2 x barrel spacers.
Next will be the PETG barrel assembly.
In my example, i use 1ft length barrels.
Cut 8 x 1ft PETG tubes and slot them into the barrel spacers, check that they are all aligned.
Do NOT glue the barrels in yet! We still need to mount the barrels onto the main turret assembly later.
This is the main component of the turret system, which comprises of the connection and turret rotation points.
Cut 1 x 4.5cm length 16mm PVC pipe, 1 x 2cm length 20mm PVC pipe and 1 x 2cm length 16mm PVC pipe.
Epoxy glue them together vertically, make sure they are aligned with the barrel spacer positions.
Build up the rest of the turret fitment parts.
Note that i design my turret connection point to connect to 20mm pipe couplers which i use in all my modded blasters, if you use other kinds of couplers, you'll have to adjust accordingly.
Cut 1 x 2cm length 20mm PVC pipe (as the connection point), 1 x 4.5cm length 13mm PVC pipe (to slot into the main nozzle to reduce deadspace), 1 x 5cm length 16mm PVC pipe (as the barrel spacer holder and rotation point) and 1 x 1cm length 13mm PVC pipe (as a base for the bottom turret "barrel stopper", explained later).
Epoxy glue everything in.
Prepare the turret system.
Cut out a suitable sized ring of foam padding and attach it on the top nozzle for the turret seal, put a rubber o-ring around the middle rotation point (i used a Nerf Stampede o-ring, apply grease to it so that the rotation is smooth) and stack some foam inside the bottom section along with a dome shaped stopper (i used a plastic button from a coat).
The dome shaped part at the bottom acts as a "barrel stopper", when the turret turns, the stopper will be pushed back and compress the foam behind, then when the next barrel is in position, the stopper pops back forward and locks the barrel in place.
My earlier designs used a toothed clutch system, but i found that too troublesome to make (alot of tedious precision cutting of the PVC sections needed), and they were not really required since there isn't an integrated auto-rotation mechanism anyways.... the system just required something simple to hold the barrels in place.
Connect the turret system to the barrel assembly.
I used 1 x 1cm length 16mm PVC pipe as a fastening collar to secure both components together, bolted on with 2 x machine screws. This also facilitates easy changing of parts if required.
The fit of the fastening collar is very important, make sure it secures the parts tightly (but still allowing smooth rotation with the o-ring), this keeps the barrel assembly constantly level with the air exit nozzle at the top section. This is essential to achieve 100% turret air-seal.
The barrels can now be glued in permanently if you wish... but in my case i leave them secured by friction fit, i've test fired hundreds of shots and they all still stay in position (just adding an extra layer of tape on the looser barrels did the trick), so i can also have the option to change the barrels anytime if needed.
Every barrel has been tested with 100% turret air-seal, the plunger stops mid-way when the barrel is blocked and it can even vacuum load foam darts too.
Completed SGN-8T : Modular PVC Turret!
Edited by SgNerf, 21 August 2011 - 03:00 PM.