Binocular Tripod Mount

Binocular Tripod Mount

I inherited a pair of 1945 vintage Navy Surplus Binoculars. These are 7 x 50mm binoculars and weigh approximately 3 pounds (1.4kg). I have many fond childhood memories using these binoculars with my Father. I can remember looking at the moon through them and it was difficult because it was hard to keep the binoculars centered on the moon. Having the binoculars on a tripod would have made them so much easier to use.

For the August 2017 Solar Eclipse, we were going to be viewing in the path of totality. I wanted to have these binoculars mounted to a tripod to make viewing easier and to allow me to take some hand-held cell phone photos through them. I decided to see if I could design and 3D print a binocular tripod mount.

The binocular tripod mount was designed in Fusion 360 and printed in PLA on a Kodama Trinus 3D printer. No supports were needed to print the mount.

The binoculars have a central pivot point that incorporates a metal rod. I chose to fasten my tripod mount to this central rod as it was structurally robust, close to the center of gravity of the binoculars and convenient. The mount is designed with a foot that includes a threaded insert ( a nut with ¼-20 threads) that allows the tripod’s mounting screw to engage and firmly hold the mount’s foot to the tripod.

The top of the mount is forked and fits around the central pivot rod of the binoculars. The pivot rod is captured by the mount and a spacer that includes a half round to match the pivot rod profile. The spacer slides down between the forks of the mount. The spacer and therefore the pivot rod are clamped to the mount by a sliding clip that engages groves on either side of the forked portion of mount. The spacer was sized so that the clamping clip fits very tightly. The mount is very firmly attached to the binoculars.

In designing the mount for 3D printing I wanted to avoid all supports so I laid the mount on its side. The foot surface that mounts to the tripod is 90 degrees to the build plate. The foot has to have a nut inserted from the 'top' of the foot so the tripod mounting screw can engage it from below. To get access to the hole and location where the nut is supposed to be located I needed to have an opening above the nut's location. I decided to make a triangular opening so that I could have the sides of the opening printed at a 45 degree angle so that I could avoid having to have supports. The sides just print nicely on their own.

When I designed the clip I actual drew the clip on top of the fork as if it was installed in place. I provided 0.5mm of gap to allow it to slide into place. I then moved the clip out of the way so it could be seen easier and to be printed separately. In most of the screen captures the clip is shown closer to the forks and the spacer is located behind it – out of order of how they are actually installed.

I have attached the Fusion 360 archive file so you can modify the file if you like. I have also attached STL files of each of the three parts; Body, Slide and Spacer.

Orienting the tripod mount on its side seemed logical in order to avoid having to provide 3D printing supports. The foot of the mount needed to have a nut with ¼-20 threads inserted so access behind/above the base of the mount was needed. In order to avoid supports you can see that this opening was printed as a triangular opening so that the sides were at a 45-degree angle and did not require supports.

The top of the mount is forked and fits around the central pivot rod of the binoculars. Slide the mount between the optics and up over the central pivot rod.

Insert the spacer with the curved side down to match the shape of the pivot rod. Slide the spacer down between the forks of the mount.

Slide the clip into place on top of the fork to capture the spacer and pivot rod. The spacer was sized so that the clamping clip fits very tightly. In fact, I had to use pliers to get the clip to slide into place.

The 1/4-20 nut was pressed into the opening in the foot of the tripod mount from the opening behind/above.

You may have to enlarge the hole in the plastic of the foot to allow the threads of the tripod mounting screw to easily fit through the plastic to get to the nut. It's a good idea to test fit this before installing the nut.

If the nut does not fit snuggly it can be encouraged to stay in place with a drop of glue. ;-)

With the binoculars firmly attached to the mount the mount can be attached to a tripod. The tripod mounting screw screws right into the 1/4-20 nut.

The binocular mount performs flawlessly; firmly attaching the binoculars to the tripod, making viewing much easier. It is so nice to be able to view hands free and not have to hold up 3 pounds of binocular for any length of time!

I really enjoyed having the binoculars on a tripod. It made viewing the eclipse so much easier and let me take some wonderful photographs.

I adapted the filters from cardboard eclipse viewing 'glasses' to mount over the binocular lenses. This allowed me to take some great partial eclipse images. The filters were removed when the total eclipse was in force.

Enjoy!