EHC Knobs - Control Knobs - Micro Vernier Reduction Drive Knobs Details

Providing input shaft ratio, for fine tuning & precise control. The EHC Micro Vernier Reduction Drive Knobs are available with a range of custom options.

EHC Reduction Drive delivers a variety of ratios & mechanical interface options.

• Ratio Reduction Control
• Easy to Install
• Backlash Friction Drive

The EHC Ratio Reduction Knob Controls are available with a Locking Micro Vernier option - A friction lock mechanism, designed to prevent movement.


The EHC Reduction Drive Knobs provide input shaft reduction ratios, ideal for fine tuning through a backlash planetary friction drive mechanism. The EHC Micro Reduction Drive offers a variety of standard ratios and mechanical interface options.


• Zero backlash
• Integral assembly
• Infinite resolution with absolute shaft registration
• Driving torque-10inch-ounces
• Saves space behind the panel
• Simple installation, no special tools required
• Knob and component shaft rotate in the same direction
• As small as1”diameter, front or rear mounting

Micro Venier Ratio

"A” Vernier Drive 10:1with“B” Direct Drive 1:1
“A” Vernier Drive 40:1with“B” Direct Drive 4:1
“A” Vernier Drive100:1with“B” Direct Drive10:1

*MicroVernier Ratio  - Contact us on: 01524 770 777 for more detailed information.

MicroVernier with Locking Mechanism

A Locking EHC Micro Vernier is available with a friction lock mechanism to prevent inadvertent movement of the setting, integral to the unit.

RDL61 Reduction Drive

A ball drive device with a 6:1 reduction ratio:

• Dial flange is directly coupled to output shaft
• Provided with 2x 2:56 x 3/16 pan head slotted screws &  x 6:32 x 1/8 set mounting screws
• Working temperature range 0ºC to 55ºC
• Storage temperature range -40ºC to 70ºC
• Torque values:Output >26inch-oz.; Input >3inch-oz.