For more information and background, please read:
http://www.thetylergibson.com/improving-spectator-view-a-usable-hololens-mount

Amazon wishlist for all the optional goodies that make life easy with this mount:
https://www.amazon.com/gp/registry/wishlist/2CVA3M6A6YEED/ref=cm_wl_list_o_3

Three mounting options

All three of the brackets are 3D Printable on most consumer 3D Printers. With a build volume of just under 200mm95mm75mm, and two of the three are designed to print without any supports.
The center mount point is positioned at the HoloLens’ center of gravity at a height offset that should fit nearly every DSLR camera on the market today.
You will only need to remove the nose-piece before installing any of the mounts. You will need to drill each screw hole out to size after printing. I did this to enable you to use M5 machine screws if desired, or drill out to use 1/4”-20 screws. I used a #3 drill bit with very good results, but you should measure twice and drill once.
I highly recommend using either PETG or ABS as your print material. My mounts are all printed with Hatchbox PETG @ 250c on a e3dv6 hotend with .2mm layer heights. I used 50% infill and 3 perimeter layers with 8 layers top and bottom. This will produce an extremely rigid part.

Mount 1: Light and simple

The first mount option is for folks who want the absolute least weight. It has a single hot shoe screw mount. You will need to purchase a set of Velcro cable ties, a Tripod Screw hot shoe adapter and one 1/4”-20 nut. You will need to print this mount with supports. Print, insert into the cutouts on each arm of the HoloLens and use 4 cable ties through the cutouts to secure the arms to the mount securely. Ream the tripod mount hole with a drill bit. Press fit the nut in the cut-out (you may need to use a pair of pliers or a clamp to get the nut securely pressed into place) and then secure with the tripod screw hot shoe adapter.

Mount 2: Simple and flexible

The second mount option uses the same Velcro ties, but has a more traditional mounting plate configuration. It provides 1/4"-20 holes spaced 9mm on center alternating with 3/8”-16 holes. The tripod drop mount still provides a standard 1/4"-20 center hole with countersink for a nut. The drop mount area also features additional 1/4"-20 holes for more secure mounting to camera cage rigs as well as ARRI 3/8”-16 mounts with pogo pins for alignment.
This mount is useful if you want to mount other gear to the bracket, especially if you’re mounting to a camera cage. I use the internal volume to mount my Tascam audio recorder and wireless mic receiver.
You can optionally use the top mount plate with this mount for a super-secure and rigid rig. The top plate slots into the risers snugly. Secure the top to base with two 1/4" bolts through any of the internal holes in the cheese grid.

Mount 3: Heavyweight

This mount provides the most flexibility for professional operators. It moves the drop mount to a separate printable adapter and just provides the base plate with cheese grid. Similarly to mount 2, you can secure with Velcro straps or use the top mount place with 1/4” bolts.
This mount is useful if it is being installed as part of a larger camera rig system or larger cage.

I hope this helps you create even better mixed reality experiences, and happy coding!

Rigidbot Big

No

No

0.2mm

50%

Use PETG or ABS.

The cheese grid is designed to work with both M5 and 1/4"-20 screws. For M5, you can thread directly from the printed part. For 1/4"-20 you will need to ream the holes out larger with a drill bit. A #3 bit worked well for me, but you should double check for yourself.