Scope of application: This high-quality rod coupler is widely used to connect servo motors, stepping motors, encoders, screw drives, mechanical platforms, etc. Final question. On the flexible couplers, there are four screws. I've only tightened the two that clamp onto the motor shaft and ACME screw. What about the other two - they seem 8mm Flexible Motor Coupling Jual Stepper Motor Flexible Shaft Coupling Coupler 6.35x8mm Online Shaft Coupler These are torsional stiffness, backlash, torque, life, and attachment system. uxcell 8mm to 8mm Bore Rigid Coupling Set Screw CNC Milling Machines 6 Pvc Coupling BQLZR Blue Aluminum Shaft Coupling Motor Connector With Spanner Pack 811159 Quick Couplers Specifications: The flexibility of this coupler removes stress between the motor and driving... This high quality shaft coupler is widely used to connect servo motor, stepper motor, encoder, screw driving, machine platform, etc., Material: aluminum alloy Brand New CNC 8 x 8mm Shaft Coupler Flexible Coupling Servo Motor Connector ... $1.00 (7%). Sold by: Bqlzr. $12.95. FREE Shipping. Taxes calculated at checkout Motor Shaft Coupler Coupling