Fully 3D Printed External Battery Head Brace Mod for Oculus Quest 2

Hello, and welcome! My name is Sebastian, and I'm a Freshman at Suncoast Community Highschool in Florida. I am currently an IB student at Suncoast and as part of my program, I am required to create a "Personal Project" over the summer. As for my choice, I chose to learn about some Fusion360 skills and challenged myself to apply them in a project. I've already created my first project utilizing Fusion360, xMod an affordable, sustainable, and modular alternative to traditional housing, and you can check it out here: xMod Instructable. I've now moved on to create a solution to a problem I've been having for a long time now: short-live battery life on my Oculus Quest 2. To fix this problem, I created an external battery mount for my Oculus that also serves as a head brace that balances the weight of the headset evenly. Like most of my Instructables, I will take you through the design process step-by-step and hopefully teach you some new things that you may not have known previously. Additionally, I will also show you how to assemble and mount the external battery mount. I hope you enjoy, and let's get started!

Supplies Used

-Hatchbox Orange PETG Filament - 1.75MM, 1KG Spool - Link

Parts Used

-3D Printed Oculus Brace MK2 - 1x

-3D Printed Battery Mount - 1x

-3D Printed Oculus Brace Buckles - 2x

Tools Used

-Prusa I3 MK3S+

All STL, STEP, and G-Code files that I've used can be found on my Printables Page. You can use the STEP Files to modify any aspect of the original design to suit your particular VR Headset

Unlike my previous instructables, in this instructable I will going through the steps of actually modelling the part so that you can modify the step files provided to suite your own VR Headset. I'll also go through some tips and some other details that got me to the final product. Now, lets get started!

Design Steps

1.) First, I created an ellipse that suites my brother and I. I got the measurements for the ellipse by simply measuring the length and width of the lower back part of the head, the occipital bone (I guess memorizing the parts of the head in biology does actually come in handy XD). After measuring both of our heads, I just averaged out the measurements and got 125x100MM. You could also design several head braces customized for each user because they are easily swappable.

2.) After created the ellipse, I created a line tangent to the ellipse near the bottom of the ellipse. The length of this line will affect how concave the head brace will be, so you can adjust this value to your needs. After creating the line I just mirrored the line across ellipse and then trimmed unnecessary part of the ellipse.

3.) After trimming, I offset the ellipse portion by 20MM to create the main head brace. I then went on to create a 12MM line at 90 degrees to the tangent line. I then finished creating the main head brace profile by connecting the offset ellipse and the 12MM line.

4.) With the profile created, I then filleted the corners on each side by 6MM. After that, I connected the center points of the fillets to create a line and then connected the points where both lines meet the ellipses. I finally connected the midpoints of the lines I created. This line would serve as the mid point for the buckle that makes the head brace concave.

Background Info - You may be wondering "How did you know that buckling the corners would make the brace concave?". I got this idea when I was fiddling around with a paper, if you pinch and fold a piece of paper over itself, the paper will become concave. I applied the same idea to the head brace so I wouldn't have to model it concave from the get-go and have to waste a lot of filament on supports.

5.) After creating that line, I created the holes for the buckles to fit into. I made sure to leave some extra space so that the actual buckle would easily fit into the holes. For example, in my scenario I used a 4.5MM base and 8MM head for the buckle so I would make the opening hole 8.5MM and the locking hole 5MM. I used the same principle throughout the design.

6.) Lastly, I extruded the profile to create the main brace. I then created another sketch and used the same process as I did with the holes to align the buckle (Step 4). I made sure to space the buckle to the point where the natural resting position would be locked (essentially further down than the opening whole on the main profile). I then created the 4.5MM diameter circle and extruded 2.5MM to clear the thickness of the head brace. I then created the 8MM head of the buckle, extruded 2MM, and filleted the corners by 0.75MM. Finally, I filleted the corner where the neck of the buckle meets the head of the buckle to the point where it meets the main profile ( About 3.2MM) so that it would not require supports when printing.

3D Printing

1.) To print this part, I used my Prusa I3 with a 0.8MM nozzle. I used PrusaSlicer to slice the part at 0.3MM Detail Layer Height so that the buckle would print nicely. I recommend bumping up part cooling when the print reaches the buckle layer as you may encounter some difficulties there. Finally, I recommend using PETG because of its strength and ease of use. You can access my G-Code through the Printables page in the supplies section.

Design Steps

1.) First, I started by creating the main buckle portion. To do this, I measured the dimensions of the Oculus' strap which turned out to be 31MMx2MM. With these dimensions in mind, I created the back part of the buckle which was a 35x2MM rectangle. I then went on to create the sides of the buckle by creating a 2x4MM Rectangle and then creating a 2x7MM rectangle adjacent to the original. I then went on to extrude the profile 25MM.

2.) After extruding the profile, I then went on to create the opening for the actual locking head to pass through. In order to do this, I first created a 12MM circle on the back face of the buckle and then created an 8MM circle on the same center. I then extruded the 12MM circle 1MM and then the 8MM circle 2MM. I did this so that the locking head would be able to pass partially through the buckle but not all the way.

3.) After creating both of these holes, I then went on to chamfer the inner edge of the 12MM indent so that the locking head would sit nicely on the main buckle. I also made the buckles this way because 1: a two part buckle reduces waste by eliminating the need for supports and 2: Can be easily interchanged between longer locking heads for other accessories.

4.) After created the base of the buckle, I went on to create the locking head of the buckle. To do this I started out by creating a 12MM circle. I then extruded this circle by 1MM. Then, I created a 4.5MM circle on top of the 12MM circle. I extruded the 4.5MM circle by 7MM, you can adjust this value to your needs if you decide to use a different accessory with these buckles. I then went on to create the 8MM circle at the very top and extruded it by 2MM.

5.) Lastly, I cleaned up the locking head by apply some fillets and chamfers. First, I filleted the top and bottom sides of the head of the locking head by 0.75MM. Then, I filleted the bottom side of the head to a degree where I wouldn't need to apply supports (About 3.2MM). Finally, I chamfered the bottom edge to match the edge on the buckle.

3D Printing

1.) To print this part, I used the same settings, filament, and printer as the part before. I recommend that you print the main buckle portion on its side so you won't need to add supports. Also, remember that you will need to print 2 of these buckles. Like the head brace, you can access my G-Code through the Printables page in the supplies section.

Design Steps

1.) First, I create a spline that runs 100MM long with a 12MM high point. I measured this AFTER I printed out the head brace and buckles. If you want to adjust this value, I suggest that you print the other parts just to make sure that your value will work. After creating the spline, I created a 2MM offset of the spline. Notice that the value was not negative, this is because the inner spline is the one we measured for so we don't want to use an offset. After creating this profile, I extruded it 90MM up.

2.) After creating this body, I created another sketch on the bottom portion of the body. I projected the offset spline and created a "rectangle" with the bottom side being the offset spline. I then extruded this rectangle to create the bottom part of the external battery mount. I then went on to create another sketch, offsetting the rectangle I created before by -2MM. I extruded this profile 30MM upwards to create the wall of the battery mount.

3.) After finishing the basic body, I went back and cleaned up all the corners. To do this I selected all the bottom and inner corners and filleted them by 5MM. Then, I went to the sides of the box and filleted those as well. I suggest you keep the fillet value quite low if you are going to make a variation as you want to make sure that you have plenty of flat surface area for the printer to make its first layer.

4.) Lastly, I went on to create the mount holes. To do this, I created a sketch on the XZ plane and projected the geometry of the battery mount. I then created a line perpendicular to the top side of the geometry so I could then create a plane at an angle (±15 Degrees). I then proceeded to create the exact same mounting holes from the head brace and extruded and mirrored the operation.

3D Printing

1.) To print this part, I used the same settings, filament, and printer as the part before. I recommend that you print the battery mount with the bottom of the mount as the first layer, don't worry about the mounting holes they won't need supports at 0.3MM Layer height. Like the buckles, you can access my G-Code through the Printables page in the supplies section.

Assembly Steps

1.) First, get both buckles that attach to the Oculus' harness. To attach the buckles, first push the locking head through the hole on the buckle. After pushing the locking heads through, place the top part of the harness into the top part of the buckle, and then, fold the harness in half with the edges facing towards the buckle. After folding the harness in half, try to fit the bottom part of the harness into the bottom part of the buckle. Repeat this process for both buckles, and make sure that you have placed your buckles about 100MM-125MM apart.

2.) After attaching the buckles, get your head brace and buckle it up to make it concave. Carefully, place the locking pins from the buckles into the unlocked position on the head brace and move it upwards to lock the head brace in place.

3.) After Attaching the head brace, get your battery mount. To attach the battery mount, bend the front part of the battery mount and carefully position the locking heads of the buckles into the unlocked position on the battery mount. Finally, push the battery mount downwards so that the battery mount is locked. Make sure to keep the head brace in the locked position while performing this step.

I've already used the head brace and battery mount for about a week now and I've been consistently getting about 2 hours worth of extra gameplay with my battery. Also, I feel that, with the head brace and the weight of the battery, the headset's weight is distributed more evenly, causing less fatigue. Overall, I think its a great mod that is fairly easy to make with a 3D printer at about 50grams and 3 hours of print time. I hope you enjoy the mod as much as I do!!

Happy VR-ing!!

-Seb