Leica Summicron-R 50mm f/2 follow focus gear

A 3D-printable module 0.8 follow focus gear for the Leica Summicron-R 50mm f/2: a free slip-on STL or a clamp ring for your follow focus or wireless focus motor. Start with the saved measurements below, check them on your copy and print a test ring first.

Clamp ring for this lens with automatic outside diameter. The ring and the measured surfaces are to scale; the lens around them is a schematic.

Saved measurements
Mount	Leica R
Version	Version I
Focus-ring contact diameter	59.4 mm
Clamp opening (+1 mm allowance)	60.4 mm
Ring width	10 mm
Ribbed focus grip	4.2 mm

Lenses vary between versions and copies: measure yours with a tape before printing.

Choose your ring

Slip-on focus ring

A slim module 0.8 gear with this opening and width, dimensions engraved inside. One STL, no account.

Free

Clamp ring

Three built-in clamps with M4 set screws hold it on the lens. STL, print and assembly notes, hardware list.

€14.90

Added hard stops are for mechanically coupled focus rings without usable end stops. They are unnecessary on lenses with built-in stops and unsuitable for focus by wire. This preset is offered for clamp and slip-on rings.

Several lenses? Every further clamp or hard-stop ring in the same order costs €9.90. Keep one outside diameter and your focus motor stays in place when you swap lenses.

Before you print

Check the focus-ring diameter on your copy. A tape circumference must be divided by π to obtain its diameter.
Print a test ring first. Material, printer and shrinkage change the fit.
Module 0.8 teeth fit standard follow focus units and focus motors from ARRI, DJI, PD Movie and Tilta.
New to this? Read how to measure a lens for a focus gear.

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