SRP-2 Recoiling Foam Dart Blaster

UPDATE 8/17/2023: Updated Build Guide from v0.1 to v0.2. This includes more information and links in the electronics and internals section of the Parts List, more specifically adding the specific battery needed to fit inside of this blaster's battery compartment. Slightly edited Hardware portion of description to point more clearly to the Build Guide.

UPDATE 8/16/2023: Edited Contact Me portion of description to specify how to DM me. I will generally not be accepting random friend requests, so please join the /r/Nerf Discord server linked below for now.

BLASTER OVERVIEW

The SRP-2 is a flywheeler half dart pistol that accepts straight Talon mags and also has a slide that recoils upon trigger pull. It uses 130 motors and nightingale flywheels, and promises a more engaging pistol experience with FPS upwards of 110. I designed this as basically a modern Dessert Pigeon Mk8 by MHP. Like the Dessert Pigeon Mk8, the slide recoils upon trigger pull, it has a slide lock, it accepts straight Talon mags, and it is a micro-flywheeler. However, the SRP-2 is built from the ground up using a more comfortable grip angle, HK-inspired styling, uses more commonly available hardware, and is overall more compact than the Dessert Pigeon.

The battery tray is designed to fit Nightingale batteries, and that's pretty much it. I know that the 3S 550mAh 80C batteries fit, and in general should be enough to power this blaster, since all there is being powered is 2 motors.

It has multiple parts that can be easily swapped out to customize the blaster, and I have included STEP files as well so you can easily design your own attachments!

TOOLS REQUIRED

All you really need to build this blaster is a set of metric hex keys, a soldering iron, some cutting pliers, and a decently-tuned 3D printer that has a 220x220mm bed (so basically any Ender 3 class of printer). However, due to this being a 3D printed blaster, you may need to sand and trim certain pieces. A recommended set of tools is listed below:

• Cutting pliers
• Metric hex keys
• Soldering iron
• Solder
• Wire stripper
• 3D printer with a 220x220x250mm print volume
• Heat set insert tools for your soldering iron
• Cyanoacrylate glue
• Sandpaper and/or hand files

If you purchase the linked heat set inserts, the kit will come with some tips that should fit certain soldering irons. Using them will make installing the heat set inserts way easier; trust me, you don't want to have to deal with crooked inserts.

HARDWARE

The SRP-2 requires very little in terms of specialized hardware; it uses readily available metric fasteners and heat-set inserts, which you can find on Amazon using the links in the included build guide's parts list. The springs used in this build are from a spring kit I got at Home Depot; I give approximate necessary dimensions for springs in the build guide's parts list if you don't have a Home Depot near you. Keep in mind that trigger reset, trigger weight, and magazine release weight all were designed with these Home Depot springs in mind, and that using too light springs will make the blaster not function correctly or jam up a lot. 

A full parts list for this blaster is located in the Build Guide. You can find the Build Guide in the files section of this model. This parts list includes all necessary hardware, electronics, and other internals.

ASSEMBLY

The included build guide will guide you through assembly of this blaster. The build guide is a WIP, so if you have any suggestions or find any typos, please contact me. 

Certain parts may require glue, sanding, and more. This is way more of a complex build than an NSP-1k or a Gryphon, with a lot more moving internal parts that require pretty tight tolerances and fitment to work correctly. You may need to adjust such things as the feed ramp to get it to feed correctly, as the design is basically forcing a dart out of a straight talon at an odd angle. This requires some testing and sanding to get it smooth enough to reliably redirect darts into the flywheels.

The build guide is mainly a reference to use during assembly, and you may need to not follow it exactly to get your blaster to fit together and work correctly. As stated before, this is not a beginner friendly build! If you are really stuck, contact me via the methods listed at the bottom of this description.

3D PRINTING

For the base blaster, there is only about 30 parts you need to print. This will take you about a week of printer runtime and about 1.25kg of filament. I have grouped the files by color. Please print orange parts in orange and the rest of the parts in brighter colors; this blaster can be mistaken as a firearm if printed in dark colors!

If you plan to run this blaster continuously for a long time period, I'd recommend printing at least the frame, slide, and flywheel cage in PETG, as the motors will potentially start melting the blaster. I personally haven't experienced any melting using PLA, but I haven't ran more than 50 darts through it in quick succession. (I only have so many magazines, maybe this is an excuse to buy more…)

There have been issues printing some of the taller primary color parts, so files that also include adhesion aids are included. I had a few of the tall parts pop off the build plate when they were 95% completed, which is very annoying and wastes filament. Depending on your printer, your mileage may vary if you really need these or not.

All the main files come pre-oriented, so you won't have to mess with figuring out how to place things. This is the optimal orientation that I have found. Most parts will be able to print without any supports, however some will require supports from the build plate, such as the Frame and the Dart Guide to name a few. This entire blaster is designed to be printed with an 0.2mm layer height. Below is the recommended print settings for each part:

• ALL SECONDARY COLOR PARTS:
  • 4 walls
  • Octet infill pattern
  • 60% infill density
• ALL PRIMARY COLOR PARTS:
  • 4 walls
  • Octet infill pattern
  • 100% infill density
• ALL ORANGE PARTS:
  • 4 walls
  • Octet infill pattern
  • 60% infill density

ACCESSORIES, REFERENCES, AND EXPERIMENTAL PARTS

I have included STEP files for the barrel, battery tray, and basically all of the slide parts to make it easier to design alternate parts and customize your blaster! (STEP files are provided for non-commercial use only, per the Creative Commons license for this blaster.)

There are a few experimental parts included too:

• Slide w/ RMR mount
  • I have no idea if this works well, and personally I think RMRs look silly on the SRP-2 due to how big the pistol is and how small the RMRs are, but you can mount one on the slide. Do note, this probably will make the trigger pull even heavier, since now you aren't only moving the slide itself but also a metal sight mounted to it.
• Threaded Barrel
  • This allows the use of the included suppressor model. My main concern is that with a heavy enough thing hanging off the end of the barrel, you might snap the threaded portion off by aggressively swinging the blaster around. For reference, the thread is M22-2.2.
• Suppressor
  • Its modeled roughly off of the suppressor commonly seen on the HK Mk23 SOCOM. If you do try to run this, I would make this part as light as possible. A low infill would probably be the best so you don't end up possibly snapping off the barrel.
• Sight Inserts
  • A few sight inserts for the holes present on the stock sight pieces. On my personal SRP-2 I printed these using glow in the dark filament, which basically allows you to mimic having tritium sights, but without the annoying radiation! Printing these in a contrasting color to the other sight parts is recommended.

SUGGESTIONS, QUESTIONS, OR ISSUES? CONTACT ME!

I can be found on Reddit and Discord, but I am most active on Discord. I can be found on the /r/Nerf Discord server, but if you need, you can DM me. If you do make this blaster, I'd love to know!

My Discord username is: @brooklyn_tony198

My Reddit username is: u/BrooklynTony198

Please note that I will generally not be accepting friend requests for DMs; to DM me on Discord, please join the /r/Nerf Discord server first and DM me through there.

IF YOU WANT TO SELL HARDWARE KITS OR PRINTED COMPONENTS OF THIS BLASTER, PLEASE CONTACT ME FIRST.

NONE of my files are to be used or sold by Frontline Foam, by downloading my files, you agree that you are not Frontline Foam and/or related to Frontline Foam or Derrikk Sun.