This folder contains the mechanical assets necessary to build a Project North Star AR Headset with calibration stand.
Mechanical Release 3 bundles together all the lessons we learned into a new set of 3D files and drawings. Its main objective is to be more inviting, less hacked together, and more reliable. The design includes more adjustments and mechanisms for a larger variety of heads and facial geometries. Overall, the assembly is lighter, more balanced, and stiffer.The parts were designed for an FDM style 3D printer
This is a work in progress. This is not a finished guide, nor end-user friendly.
Major sections are missing. Assembly requires care and patience. Nothing worth having is ever easy.
CAD Render
Getting Started
Open the and construct each sub-assembly as illustrated. A full list of the parts needed can be found in the . Not all sub-assemblies are required as there are multiple designs to choose from. Additionally, the CAD files are included in STEP format to help design new parts.
Design Overview
The headset consists of two basic sections: the optics and headgear . The optics subassembly currently has two variants: Release 3 optics and Update 3-1 (i.e. the simplified optics assembly). The headgear assembly utilizes the rear adjustment mechanism from a Miller branded welder’s helmet, but several models can be made to work.
Optics assembly: Release 3 vs 3-1
Functionally, the two optics assemblies are the same. Release 3 is closer to the original design aesthetic and it’s marginally (8g) more lightweight. On the other hand, Update 3-1 halves the print time by removing the need for supports on the sides. Overall, the simplified 3-1 bracket is easier to print with lower print failures and stiffer too. It’s recommended to start with the simplified Release 3-1 optics assembly for the first build. See drawing for more information.
Notes on 3D printed parts
All development was done using filament. We've found it to be strong, easy to print, and have great surface finish.
A build plate of approximately 250x200mm is recommended for the largest parts
.25mm layer height, 2 perimeter shells, 15% infill
Filament: eSun PLA Pro (PLA+)
3D Printer: MakerGear M2
Slicer: Simplify 3D
Installing heat set inserts
Several parts in the optics assembly use brass inserts for increased clamping load and the ability to swap out the components multiple times without wear. These inserts need to be heated above the plastic's melting point and pressed into the plastic. It's recommended to use an installation tip designed for brass inserts.
Demonstration of using a soldering iron to install brass inserts. The wire cutters are used to prevent the insert from pulling back out when not using an installation tip.
Parts that require inserts:
Display trays (4 inserts each) - and
Driver board mount (2 inserts) - /``
Installing brass inserts into the optics bracket is optional. They're intended as mounting points for future testing.
Bending thermoplastics
The headgear assembly includes parts that print flat but bend to fasten to each other. Although not necessary, it’s suggested to drape these parts around a form while the 3D print is still soft from the heated print bed. This minimizes strain inside the plastic and prolongs the life of the part.
Preheating the print bed to 70C softens a print enough to shape the part
Changelog
All notable Mechanical changes will be documented in this file.
August 21, 2019
Added
BOM for Update 3.1 Assm
Cable guides (#113-002, #114-002)
Changed
Simplified folder structure
Updated BOM with links
Exported updated CAD STEP files of assemblies
Associated part numbers with simplified assm (#130-003, #130-004, #130-005, #130-006)
May 8, 2019
Added
New endcap with M2.5 screw mount (#110-005, #110-006)
Changed
Cutout size and shape for al. bar slides (#110-003, #230-002, #240-002)
Apr 18, 2019
Added
Modular lid and Vive tracker mount (#130-002, 3, 4, 5, and 6)
Blank mounting plate STEP file
Apr 12, 2019
Added
New slide end cap with cable mount (#110-003)
Changed
Chamfer on optics bracket display screws, removed lip around rubber washer (#130-001 and #110-001)
Mar 23, 2019
Added
Added simplified optics assembly (#130-000)
Flattened bottom for easier printing (#112-002, #111-002)
Thickened and fillet corners for strength (#230-001,#240-001)
Keyed mates for faster assembly (#220-001,#220-002,#210-003,#210-004)
Thickened for strength, offset edges, removed old cable guide holes (#130-005, #130-006)
Added L+R labels to headgear for easier assembly (#230-000, #240-000)
Added corresponding screwholes for cable guides (#113-001, #114-001)
Parts may need to be rotated to align with print bed.
Some parts have optimized versions (labeled “FDM OPTIMIZED”) with extra plastic tabs that need removing. These versions aid in minimizing warping and gripping the print surface.
A video guide from Tasuku Takahashi is available below, it's best to supplement the written documentation with this video. If you run into problems or have questions, feel free to reach out on the discord.
Item No 6 (#230-004) of the Left Brake Assembly was removed and thus no longer packaged due to undesired cable catching. The new method of managing cables is by attaching a zip tie to the end cap.
000-000
100-000
110-000
130-000
111-000
113-000
120-000
121-000
131-000
200-000
210-000
230-000
Item No 6 (#230-004) of the Left Brake Assembly was removed and thus no longer packaged due to undesired cable catching. The new method of managing cables is by attaching a zip tie to the end cap.
