Telescope Smartphone Adapter 3D Print: Build Your Own in 6 Steps

Updated November 2026

A telescope smartphone adapter 3d print project lets you mount your phone to a telescope eyepiece and take sharp photos of the Moon, Jupiter and bright star clusters. You only need a 3D printer (or access to one), a design file that matches your eyepiece size, and a few basic tools. This guide walks you through choosing a design, measuring, printing and testing the adapter so it holds your phone steady on the first clear night.

Choose a Design That Matches Your Setup

Most printable adapters fall into two groups. Clamp-style designs grip the eyepiece barrel with a tightening screw or flexible sleeve, while slide-in designs fit a fixed-size tube and hold the phone with spring arms. Clamp-style adapters suit families with several eyepieces, because one adapter can fit different barrel diameters. Slide-in designs tend to be more stable but only work with the exact eyepiece size they were drawn for.

Shopping for one? See our guide: Smartphone to Telescope Adapter: 4 Best Picks for Stargazing Families (2026).

Look for files that list their target eyepiece diameter and phone width range. Well-documented designs often state their tolerances in millimeters, which saves guesswork.

Measure Your Eyepiece and Phone

Use digital calipers or a ruler to measure the outside diameter of the eyepiece barrel where the adapter will sit. Common barrel sizes are 1.25 inches (about 31.75 mm) and 2 inches (about 50.8 mm), but many budget eyepieces vary slightly, so measure rather than assume. Then measure your phone’s width and thickness, including any case you plan to keep on.

Add a small clearance of roughly 0.2 to 0.3 mm to the barrel measurement when you adjust the design. A tighter fit can crack the print, while a loose one lets the phone drift off-center.

Print and Prepare the Adapter

1. Slice the file using PLA or PETG at a layer height of about 0.2 mm, with 30 to 40 percent infill.
2. Print the adapter flat-side down and add a brim if the base is narrow.
3. Remove supports carefully and sand any rough edges that might scratch the eyepiece.
4. Test-fit the adapter on the eyepiece before attaching your phone.

Print a quick test piece of the clamping section first if you are unsure about the fit. It costs little time and can save a full print.

Align the Phone and Take Your First Photos

Center the phone’s camera directly over the eyepiece lens. Start with the Moon, which is bright and easy to find. Turn on the phone’s night or pro camera mode, lower the exposure if the image is washed out, and use a 2 to 5 second timer so vibration from your finger does not blur the shot. Adjust the phone’s position until the camera lens and the eyepiece’s exit pupil line up, then lock the adapter tight.

Common Mistakes and Tips

• Using a tight clamp on a thin plastic barrel, which can crack the eyepiece housing.
• Skipping test fits and printing a full adapter with the wrong diameter.
• Trying to shoot faint deep-sky objects before mastering the Moon.
• Forgetting to check that the phone case does not block the camera or flash.
• Leaving the adapter on the telescope during transport, where a bump can shift the phone out of alignment.

Recommended gear

A basic digital caliper makes measuring eyepiece barrels and phone dimensions much more accurate than a ruler. View on Amazon

A small phone tripod or clamp holds the phone steady when you are not using the adapter, which helps when you are adjusting the setup in the dark. View on Amazon

A red-light headlamp preserves your night vision while you work with the phone and telescope. View on Amazon

FAQ

Do I need a 3D printer to make a telescope smartphone adapter?

Not necessarily. Many makerspaces, libraries and local print shops offer 3D printing access, and some online services will print a design for you. Ask for the filament type and dimensions you need before ordering.

Which filament is best for a telescope adapter?

PLA is easy to print and holds up well for light use. PETG is more durable and handles temperature changes better if you store your telescope outdoors or in a cold garage.

Can a 3D printed adapter damage my eyepiece?

It can if the clamp is too tight or the inside edges are rough. Sand the contact surfaces smooth and tighten gently, checking the fit before each observing session.

Conclusion

A telescope smartphone adapter 3d print project is a practical way to capture the night sky with gear you already own. Measure carefully, test your fit, and start with the Moon before moving to fainter targets. With a little patience, your first photos can show craters and planetary detail that surprise the whole family.

Related reading

• DIY Telescope Smartphone Adapter: 5 Best Picks for Stargazing (2026)
• Carson Refractor Telescope with Smartphone Adapter: 7 Best Picks (2026)
• 5 Best Universal Smartphone Adapters for Telescope (2026): Our Picks
• 5 Best Smartphone Adapters for Telescope Picks for Stargazing (2026)
• 4 Best Monocular Telescopes with Smartphone Adapter for Stargazing (2026)

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