This is pretty sweet. I have a 2.5" telescope that's getting old, but still works very well. Being a newbie star gazer, I have absolutely no knowledge of star names or know where to look for them. There are a number of apps that are very good at names and locations, so I decided to marry my iPhone to my telescope thinking it might help me out. I wasn't prepared for the result. I thought the app would get me in the neighborhood of where I wanted to be, but I had no idea how accurate the setup would be. Because the clamp is locked into position, everything is automatically set in place. The telescope's area of coverage is dead center on the iPhone's screen. If I type a star's name, the app shows me which direction to point my telescope. The app I use is Sky View. There are both free and paid versions in the app store. Sky View has a virtual reality mode that shows the actual sky along with the graphics. A target in the middle of the iPhone screen highlights the star when the scope is pointed directly at it. Not only does this make it easy for me to locate any star, but I gain a little knowledge about it as well. The device will hold the iPhone vertically or horizontally.The print is made in 2 parts so the entire project can be made without supports. The clamp portion with the hinge is printed as one part. The iPhone holder is separate. Glue this part to the clamp. I use a mixture of scrap plastic and acetone. This attaches parts together as well as a weld does. The plastic hinge worked loose on the prototype after I cranked the wing nut too hard. I've added a small hole for a wire to be inserted. Depending on what size wire is available, the hole can be enlarged to fit. Drill the hole undersize to keep the wire in place. I drilled a 0.093 dia hole through the center of the hinge I had weakened, and pressed a 0.100 stainless wire into it. Now, the part should last a long time. Post Posting Notes: With a bit of post-printing modification, this should fit a 2" to 3" telescope. Not everyone has a 3D printer, so I'm including a pop-riveted aluminum version that should be simple to make. Look at the drawing, use the concept and size it to your telescope and phone. Don't forget to put padding between the aluminum, pop rivets and your telescope. I've been bitten by the astronomy bug... I ordered a 114mm reflector and re-draw a new iPhone holder. I'm thinking of mating it directly to the spotter scope's permanent mount. I won't be needing the spotter and I can use the adjustment screws to fine tune the phone's alignment.