Simmod Simple Fit Follow Focus Gear - Mini

Follow focus gears are typically a compromise between fit and durability.
This system is designed to remove that compromise.

The Simmod SIMple Fit Follow Focus Gears are precision-machined aluminum gears designed to provide a standardized cine interface on virtually any lens, while maintaining accurate fitment across varying barrel diameters.

Construction and Gear Standard

Each gear is machined from solid aluminum and built to industry-standard specifications:

• 0.8 MOD / 32-pitch gear profile for compatibility with cine follow focus systems (simmod)
• Available in 10mm and 20mm widths depending on application (simmod)
• Outer diameters vary by size, typically ranging from ~80mm to over 100mm depending on model (simmod)

The gear profile is cut directly into the aluminum body to ensure consistent engagement with follow focus motors.

Fitment System

The defining feature of the system is its interchangeable compressible insert design.

• Each gear includes a set of rubber inserts matched to specific diameter ranges
• Inserts sit inside precision-machined internal channels within the gear
• When installed, the insert compresses slightly to create a friction-based, uniform grip around the lens barrel

This allows a single gear size to accommodate a range of lens diameters without permanent modification.

Sizing Structure

The system is organized by lens barrel diameter ranges, for example:

• Micro: ~45–49mm
• Mini: ~50-54mm
• XXS: ~55-58mm
• XS: ~58–61mm
• S: ~562–65mm
• M: ~66–77mm
• L: ~70–73mm
• XL: ~74–77mm
• XXL: ~78–83mm
• Jumbo: ~87–93mm
   

Each size includes multiple inserts in incremental diameters, allowing fine selection based on the measured lens barrel.

If the lens diameter falls between sizes, selection of the next larger size is recommended for proper compression fit. 

Installation Method

Installation is mechanical and does not require adhesives or heating:

• Measure the lens focus ring diameter using a caliper
• Select the closest matching insert size
• Install the insert into the gear’s internal channel
• Set lens focus to infinity
• Slide the gear onto the focus ring with even pressure 

Shimming tape is included to compensate for minor tolerances if needed.

Mechanical Behavior

• Creates a uniform gear interface for follow focus systems
• Maintains consistent engagement without slippage when properly fitted
• Does not require permanent modification to the lens
• Allows removal and reuse across different lenses within the same size range

Optional CineStops can be added to establish physical A/B limits for focus pulls. 

System Characteristics

• Fully mechanical solution
• No adhesives, no heating, no permanent installation
• Designed for repeatable mounting and removal
• Compatible with standard cine follow focus motors

Notes

• Proper measurement of the lens barrel is required for correct fitment
• Over-tight sizing may damage lens helicoids if forced
• Compression-based fit relies on correct insert selection

A mechanical gear system designed to standardize lens focus control while maintaining flexibility across multiple lens diameters.