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  • josephaguilarsanch

Firefall - Halo: Infinite

The most customizable MJOLNIR helmet ever designed


Major Features

The Most Customizable MJOLNIR helmet ever designed

This helmet comes with 12 optional attachments and can support up to 7 at any given time. This allows the Firefall helmet platform to support thousands of different combinations. This helmet can support the following:

- A suite of Picatinny rail compatible side attachments from Halo: Infinite and Halo: Reach

- A flat, universal overhead mounting plate

- Multiple UA attachment upgrades

- A suite of legacy ODST attachments

- Multiple removable vent covers

- The Unique Mk62 CBRN Module

All attachments are connected to the helmet by rail, 3d printed screws, or by magnets. Attachments requiring magnets will require 20x3mm disk magnets. These magnets are supported all the way down to 85% scale. This means that not a single drop of glue is required to assemble this helmet and that you will always be able to disassemble and reassemble with new exciting customizations.

This helmet comes with two common types of connectors in order to assemble the majority of the helmet. There is a master screw that comes with multiple side holes through which a small Alan wrench can be used to drive the screw. The holes in the top can also be used in conjunction with two small tools in order to spin the screw. This design was chosen as opposed to a typical hexagonal Alan key fitting as it prevents the deformation of the 3D printed plastic under the stresses of a singular twisting Alan wrench. You can view my personal assembly video to get a better understanding of the advantages. These screw allow the helmet to be securely assembled without any need for glue. The second common connector is a master peg. This common peg fits in every screw slot to make for a quicker an easier connection for quick helmet assembly and disassembly as well as a alignment tool if you do decide to glue the helmet together.

ODST Legacy Bucket

Also included, is an alternate legacy bucket that allows for the helmet to more closely resemble the original ODST helmet as it appears in Halo 3: ODST. This can be combined with all the legacy attachments to be able to recreate an updated Firefall variant of all of Alpha-Nine's helmets.

This bucket is also compatible with the UA visor attachment.

Magnetic Sealed Helmet

This helmet is comprised of a main bucket that closes around the head at the nape of the neck utilizing a magnetically attached neck seal. This neck seal supports 5 10x3mm disk magnets. The helmet will support these magnets all the way down to 85% scale.

Active Ventilation System

This helmet features two, side-mounted air intakes with internal fan integration. Each of these side vents come with optional vent covers for standard air flow, increased airflow (Dutch's vent covers), and closed air intake via the MK62 CBRN Module. The standard vent covers slot into the side of the electronics suit and rotate into place. They are held in place via a singular 10x3mm disk magnet, cordage, or a nut and bolt. The 10x3mm disk magnet is supportable down to a scale of 85% The internal electronics suite features a spot for a 40 mm fan as well as a 45 mm fan to provide airflow through these ducts. These two cavities are meant to allow for more flexibility in the size of fan that is used after scaling the helmet. For example, my personal helmet was scaled to 95%, so the larger fan slot was still able to take a 40mm fan. Additionally, there is a dedicated channel that leads to a rear battery pack located in the base of neck. The battery pack slot should be able to support either a 9V battery case or a dual AA battery case.

There is an additional overhead vent to allow hot air to flow up and out of the helmet.

Internal Audio System:

Also located in the internal electronics suite is a casing for a 40mm speaker. There is a speaker cap that will slide over the speaker to keep it in place. Both the cap and the housing itself feature a circular channel to snake through the speaker wires such that they can be snaked through channel in the base of the neck with the fan wires, or such that they can lead through the bottom of the helmet where an auxiliary cable or external audio source is located.

Scaling Templates:

This helmet comes with multiple scaling tools to ensure a perfect scaling for your new helmet. The three scaling rings slot together to form a skeleton that can let you know intuitively how the helmet will fit and how much clearance there will be between your head and the helmet walls. The entire ring may only take 2-3 to print and will save you many more hours in total printing when you can rest assured that you will get the perfectly scaled helmet during your first attempt.

Multiple Visor Options

There are multiple ways to go about fabricating complex visors such as the Firefall's visor. I included several files for different methods of fabrication for varying levels of experience. I have included a visor buck for those interested in vacuum forming, a thin shell version of the helmet for those interested in resin printing the visor, and a standard visor model for those looking to make a resin visor via mold. Additionally, I experimented with a two piece visor template system that will allow for a cheap, quick, and effective way for beginners to fabricate their own visor. See my assembly video for more info on how to turn these templates into visors. Whichever you pick, the visor is kept in place by slots and tabs that fit within the walls of the helmet itself



I have decided to migrate all the instructions to this page to help me more easily update as needed. Additionally, I'm hoping this will give you a better idea of the kind of project you will be potentially undertaking.

Links to all the products I used can be found below

General Assembly

For general assembly, almost all the pieces necessary are printable. However, for some of the magnetic pieces here is a list of all the pieces I would recommend.

10x3mm Magnets for the magnetic neck/electronics suite/vent covers

20x3mm Magnets for any overhead attachments

These magnets should fit inside the helmet all the way down to 85% scale.

Electronics Assembly

For the electronics you will need the following.

An up to 40mm circular speaker (I salvaged some random speakers from some old electronics, so I dont have a link)

An up to 45mm fan

A battery case either double A or 9V (I would recommend 9V)

An on/off toggle switch (the 9V case in the link included includes an on/off switch)

This is the mirror tint that I used for the example visor

General Printing Instructions

I have a few printing tips to give on certain pieces to ensure that you get the best print quality. These are just recommendation and are by no means the only way that these parts can be printed.

The very first pieces to print of this helmet should absolutely be the sizing rings. They can be printed flat and only take 2-3 hours for the set. In the long run this will likely save you hours if not days of printing when you can be sure that you will print the helmet at the correct scale the first time around. Keep scaling the rings up or down till you find your ideal fit and then scale the rest of the helmet to that scale. While there is a demo model that can be used for things like armor smith, this will also ensure that the throat of the helmet can fit over your head. The "neck" of the sizing ring assembly is equal in shape and size to the throat of the helmet.

The pieces are not pre-oriented so you will have to adjust them to ensure they are in an orientation more optimally for printing (flat surfaces touching the build plate). Additionally, for pieces that have no ideal flat surface, I highly recommend using the Cylindric Custom Support downloadable plug-in for the Ultimaker Cura Slicer. It allows you to place custom supports on parts to ensure that you can get much safer and reliable prints on parts with odd geometries. Some of the examples below will show these custom supports, you will need to add them, or something similar to your own prints.

The electronics suite has a nice flat surface in the rear that can be aligned to the build plate. The external faces with supports will likely need to be sanded down smooth to ensure a nice fit with the other main bucket pieces.

Similarly, the vent covers also have a rear flat surface that is good for printing

For the thin vent rail, I recommend selecting the bottom of the hinge arms to align with the build plate.

This will ensure that the layer lines run along those arms and reduce risk of snapping. Keep this principle in mind for other pieces such as the Bucket Alignment Pegs, chassis alignment rods, or Master Pegs. I would warn against this for the Master Screw however as this could effect the screw tolerances.

The Bucket Rear piece has a nice flat surface where the bucket alignment pegs insert.

While there is a similar flat surface on the bucket front piece, I recommend printing it in the orientation that it comes in. It will required custom supports on the little brim piece that actually touches the build place and some large ones right on the corners of the overhang. You can also remove the need for supports on the little overhands where the magnets insert. I have printed 3 buckets in this orientation and have not run into any issues.

The central air intake does not have an ideal orientation, so for sake of print speed, I set it on its side. It is likely you will have to sand the sides to ensure it can smoothly slide into the main bucket.

Both types of attachment ports can lie flat.

The speaker cap's internal face is completely flat

The Chin UA Attachment has a flat bottom face

The UA Visor Brim attachment does not have any ideal print orientation but I like to slightly angle it upwards until there is just a slight overhang left on the top ledge there. I still want the entire bottom surface to get standard supports so I dont angle that too high. For reference I use 70 degree support angle. Additionally as this will cause it to start printing on a corner, I like to put a small cylindrical support right on those corners

For the Beck base, I like to set it on its back to make sure there are no supports on the internal wire channels. Additionally I like to prevent any supports from printing inside the chassis alignment rod channels. Lastly I put some cylindrical supports on the overhang where the latch accent goes to ensure it has a stable platform to start printing

Lastly, the CBRN attachment has a flat rear face, and the Outer Vent has a flat surface on which it can be printed.

Use the tips above where applicable on any attachments or pieces not covered here. I hope all these tips have been useful to you, if you require any more advice or have any questions at all, feel free to contact me here on my website. I can't wait to see everyone's custom Firefall helmet!!!


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