What the thread found

• The CDM-100 motor is extremely compact and lightweight, making it suitable for setups where size and weight are critical constraints.
• Performance varies depending on which gear configuration is installed—the smaller of two available gear sizes produces significantly faster operation.
• Speed performance is comparable to established motors like Betz and Heden models when properly configured, achieving similar response times on standard cinema lenses.
• Torque output is reduced compared to heavier-duty motors, which limits its suitability for lenses with high resistance or demanding focus pulls.
• The motor operates quietly during normal use.
• At the $900 price point, the motor offers practical value for backup applications, iris control, or budget-constrained productions.
• Some users experienced minor chattering noise when used with Preston MDR focus control systems, though the cause was unclear.
• Real-world performance on actual productions has been satisfactory for moderate workloads, though it has not been extensively tested under demanding conditions.
• The motor functions as an effective iris motor regardless of its focus application performance.

Depends on

• Testing was conducted on specific lenses including an Angenieux 24-290 and a Canon lens, which may have different drag characteristics than other cinema lenses.
• Limited field experience exists—most observations come from controlled tests and light commercial work rather than extended production use.
• Chattering behavior with Preston MDR systems remains unexplained and potentially unresolved.
• Gear configuration significantly affects performance, and users must verify which gear is installed for consistent results.
• The reduced torque makes it unsuitable for demanding focus pulling tasks or high-resistance optics.

Gear in this thread

MDR

Parts

Follow Focus

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