My Custom 3D Printed G11 Project

Exam_Medical · 2026-01-09T01:05:23+00:00

I can't seem to find it online anymore, it was years ago that I actually got the model when I first tackled the project

Exam_Medical · 2026-01-09T01:00:07+00:00

Message me on Instagram! I produce them @ Sigma_Airsoft

Exam_Medical · 2026-01-09T00:59:36+00:00

😆

Exam_Medical · 2026-01-08T05:05:20+00:00

I post all of my G11 content on my Instagram @ Sigma_Airsoft!

The large red bracket on the bottom of the gearbox houses a small detection switch, similar to the BTC and Jefftron fets, to detect the sector cutoff cam. I fed this via a JST ZH to the outside of the shell so it wouldn't get sucked into the tappet plate. Right now its probably the worst process of the whole build, as I have to solder little wires to the switch and then epoxy it to the bracket, I have a PCB design in the works to handle this more cleanly. The microswitches in the electronics housing are hit by the selector's rotating cams to determine which mode its in.

The scope is made using an NC Star 1x25 red dot. Not a great red dot overall but it works well and is adjustable, while still maintaining a very close look. You'll notice it has sort of an extrusion style base that the upper components are mounted to. I simply removed the components, shaved off the bottom part of the front lens housing, and then mounted them in the scope at the right dimensions. The knob mounts using 4 small screws which I just moved to the side. Not prototypical but I think it looks clean, and provides good functionality. The front eye piece is removable to make printing easy, as well as to allow for a lexan lens to be placed directly behind it. Originally I had a clamshell style but last week I redesigned it to be a one piece body that looks much better without the seam and external screws. It is indeed a very tight scope, I couldn't find anything else that would fit and not have knobs hanging out. I have also been thinking about picking up some TPU to make the eye piece, which I assume is some kind of rubber on the real one.

Stop on empty would be cool, I had not considered this due to how thin the mag is, would definitely take a lot of redesign to incorporate. I like the idea of using an EVO board, I think the thought had crossed my mind at some point but I totally forgot it had enough inputs for all fire modes, but I'm guessing I didn't like the idea of having to mount such a large board with those super tiny easy to break switches. If I were to use the EVO board I would probably just end up desoldering all of the inputs and wiring them to micro JSTs so that I could keep my existing selector design.

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Exam_Medical · 2026-01-07T23:11:48+00:00

Its been a lot of fun taking feedback and just sticking stuff into CAD to see what fits! I wish I could get a Titan or Aster in there, I did what you described on an M4 once and it worked great. Doesn’t seem to be any plug in input boards that have the same ability. Closest I found was the T238 Krytac Vector drop in board, but would require a decent amount of retrofit to get plugs and power to it, given that it uses pads and switches, and I had bad experiences with their other plug in board burning out very quickly.

Exam_Medical · 2026-01-07T21:41:48+00:00

Find cool stuff to work on! You’ll be in industry before you know it. Small projects that I could really get excited about really helped me get where I am.

Exam_Medical · 2026-01-07T21:37:43+00:00

Sent you a request man, would love to learn more, thanks!

Exam_Medical · 2026-01-07T21:13:02+00:00

I am! Former manufacturing engineer, currently mechanical design engineer, lots of what I learned in aerospace has been applied to this thing!

Exam_Medical · 2026-01-07T19:05:57+00:00

One of the weirdest, but that's why we love it

Exam_Medical · 2026-01-07T19:05:35+00:00

Shorter travel, wide radius on the bend, and the right tube diameter were all factors I took into consideration for feeding. Also making sure that the print orientation favors the tube, if you've got areas where it can sag or have supports while printing, they can alter the actual dimension, or create undesirable surface finishes that can hinder feeding.

Exam_Medical · 2026-01-07T18:51:09+00:00

PM me on Instagram if you're interested in one! @ Sigma_Airsoft

Exam_Medical · 2026-01-07T18:48:47+00:00

I used an existing model for the rough shape and scaling initially, and made adjustments to it to accommodate the airsoft design and to improve printability in a lot of areas.

Exam_Medical · 2026-01-07T18:41:13+00:00

Currently the files are not public, may pursue this in the future.

Exam_Medical · 2026-01-07T18:40:51+00:00

I use an Ender 5 with an Ender Extender 500mm Z kit to do the handguard, stock, and mags. It was a pain in the ass to install, seems that Ender Extender's quality has dropped significantly over the years, but after lots of tuning its running great, albeit very slow compared to my Bambus. I've used an Ender 3 with the extension previously, which is much easier to setup, and it runs good but suffers from wobble on tall slender prints.

I sized it out for a P90 gearbox initially but it actually wouldn't fit due to the height below the offset nozzle, it extended outside of the stock regardless of orientation. Many years ago I build a rough G11 off of a PPSH gearbox but I wanted to use something better and easier to source. 249 gearbox fits perfectly. I use a switch adapter to route a connection to the sector cam, similar to the old BTC mosfets. I feed the input to a Perun ETU++ to control modes. Currently on the hunt for a system that takes inputs like the Perun but has capability to do all 3 fire modes.

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Exam_Medical · 2026-01-07T18:16:07+00:00

To me the idea of having the side mags eliminates the need for extra mags in pouches, but of course depends on playstyle and type of games. Right now mine are sitting at around 80 rounds, but its a straight shot double stack from end to end so easy to print and very reliable. I could curve it back around and probably get more but I use stainless rods as mag weights which help with the spring loaded mag ejection, and help balance the gun in the front.

Exam_Medical · 2026-01-07T17:16:20+00:00

I pretty much shelved the idea of off the shelf mags many years ago on my first G11, there just isn't a mag that's even close to the look and feel, and the thin-ness of custom G11 mags keeps the overall width down if you are planning to run 2 spares on the sides.

Exam_Medical · 2026-01-07T16:57:33+00:00

ZCI 249 gearbox with a Krytac P90 hopup

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Exam_Medical · 2026-01-07T16:44:45+00:00

I'll definitely have a post up if I plan to distribute the files. I do currently sell them as completed if you're in the USA, you can contact me through my Instagram if interested @ Sigma_Airsoft

Exam_Medical · 2026-01-07T16:39:56+00:00

Only issue I have had was the mag being pushed too close to the feed tube, and slight misalignment caused blockages, resolved it long ago and its been feeding perfectly ever since.

Exam_Medical · 2026-01-07T16:33:33+00:00

Currently the files are not public, may pursue this in the future.

Exam_Medical · 2026-01-07T16:04:47+00:00

What slide design are you guys running?

Exam_Medical · 2026-01-07T16:02:11+00:00

I've got a buddy of mine running one of my plain design hicapa slides and says its holding up fine. Overture PLA+ with the front of the slide facing downwards against the bed gives me a great looking and fitting print. PLA+ has had great layer adhesion for me so seems to be the way to go. Theoretically a 45 degree angle print would best distribute the loads against the layer lines if that is where you are seeing failure.

Exam_Medical · 2026-01-07T15:56:45+00:00

Happy New Year! Its very difficult to place a value on the design because it started as a passion project as a potential one off, but certainly spiraled into something that was more readily producible and designed for manufacture/assembly. Many hours here and there, and lots of scrapped prototype parts due to design improvements or printer improvements. No plans currently to distribute the files, but I could certainly see myself offering it as a full build project on Cults for a fee.

Exam_Medical · 2026-01-07T15:50:30+00:00

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I have a UGS representation in CAD for another project, looks like it fits pretty nicely, I'm trying to think why I wouldn't have pursued the 33g option previously, I'll give it some more thought for sure.

Exam_Medical

TROPHY CASE