Please watch this video for more information and to see the design process: https://youtu.be/eYADRNSjYlU
This is an adjustable tripod that is designed to mount with this phone holder: https://cults3d.com/en/tool/spring-loaded-phone-holder
You'll need to print the base and 3 of the legs. I printed them at 0.3mm layer height using PLA on my Robo 3D. They should be fairly quick prints and shouldn't need any support material.
I use #8 screws that are a 1/2 inch long. I also used 3 1/4" x 7/8" extension springs. The springs just clip on to the legs to hold the wedge in place and the screws and bolts hold the leg to the base.