Smartphone holder

I'm using the smartphone at the telescope eyepiece at all times. The most convenient way of keeping it at hand is the wrist lanyard. It's often possible to find a phone  case with a lanyard attachment holes or use the USB hole with a special lanyard plate. But all of that is not 100% reliable, nor very functional. Thus I have made my own solution: the sliding frame.

Aside from super reliable lanyard attachment point it's also providing two mounting options.

The holder is designed to glove fit my Samsung Galaxy S24 Ultra with or without protective/functional phone case(s). I have several frames like that for different cases. All providing the perfect fit with the serious tension preventing any free sliding.

On the back there is a standard photo tripod dovetail. On one of the ends there is a standard 1/4x20 camera screw hole used with camera heads, for the HD lanyard screw, and for general mounting on my instruments. Very versatile for my typical tasks. Like imaging with it or using with the telescope (on the OTA or its mount). In addition, the phone can free-stand on either side when desired.

The sliding design is not only minimalistic while 100% accidents free, but allows different lanyard configurations and mounting positions to leverage the phone CoG to your advantage. E.g. when free-standing or hanging on your chest, when used in different hand, or when you need to operate a certain app single handed or prevent your fingers obstructing the camera block.

Also note inside groves preventing the frame from pushing phone buttons when sliding. As well as the chamfered bulge on the end with the camera screw hole, which is not only providing enough space for the screw length but also serving as the thumb rest (over the base of your thumb). You can also hold it in your fingers reliably as a tiny selfie/camera leveling/panoraming stick.

You want to print it with solid infill on the side with CF PETG to maintain its dimensional stability.