8mm Rigid Metal Flange Shaft Coupling Hub

Specifications

• Inner Bore Diameter (d): 8mm

• Outer Flange Diameter (D): 32mm

• Total Height (H): 13mm

• Flange Thickness (h2): 3mm

• Center Boss Diameter (d1): 16mm

• Center Boss Height (h1): 10mm

• Mounting Hole Diameter (d2): 4mm (M3 Compatible)

• Mounting Hole Diagonal Pitch (L): 24mm

• Set Screw Thread (d3): M4

• Material: Rigid Metal Alloy

Key Applications and Projects

• Robotics Chassis: Mounting heavy Mecanum, Omni, or standard rubber wheels directly to the 8mm shafts of high-power DC gear motors.

• DIY CNC Machines & 3D Printers: Coupling large timing belt pulleys or custom lead screw mounts to NEMA 23 stepper motors.

• Rotary Actuators: Attaching custom acrylic or metal arms and levers to motorized pivots for animatronics or mechanical displays.

Unlock New Capabilities (Project Evolution) The Heavy-Duty Omni-Directional Rover: Move beyond basic differential drive! By utilizing four of these 8mm flange couplers, you can solidly mount a set of heavy-duty Mecanum wheels to four independent DC gear motors. Because these couplers are rigid and provide zero backlash, your microcontroller's PID motor control algorithms will translate into immediate, precise lateral and diagonal movements, allowing you to build an industrial-grade rover capable of complex pathing!

PACKAGE INCLUDED

• 1 x 8MM Rigid Metal Flange Coupler

• 2 x M4 Set Screws (Grub Screws)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What is the exact inner bore diameter? The inner bore (d) is precisely 8mm, designed to slip smoothly over standard 8mm motor shafts.

2. What is the outer diameter of the flat flange? The flange has a total outer diameter (D) of 32mm.

3. How tall is the entire coupler assembly? The total overall height (H) of the coupler from top to bottom is 13mm.

4. How thick is the flange base? The flat flange base has a thickness (h2) of 3mm.

5. What is the diameter of the raised center section? The raised center boss has an outer diameter (d1) of 16mm.

6. What is the height of the center boss alone? The center boss height (h1) protruding above the flange is 10mm.

7. What is the distance between the mounting holes? The diagonal distance or pitch (L) between the opposite flange mounting holes is 24mm.

8. What size are the mounting holes on the flange? The four mounting holes (d2) are 4mm in diameter. This allows for standard M3 bolts to pass through easily, or M4 bolts if tapped/forced depending on tolerances.

9. How does the coupler secure to the motor shaft? It secures using two M4 set screws that thread into the side of the central boss and press tightly against the motor shaft.

10. What thread size are the set screws? The tapped holes (d3) for the set screws use an M4 thread size.

11. Are the set screws included with the purchase? Yes, two black M4 set screws are included with the metal coupler.

12. Is an Allen wrench/hex key included? No, a hex key is not included. You will need a standard metric hex key to tighten the M4 set screws.

13. What material is this coupler made from? It is manufactured from a solid, rigid metal (typically a zinc-plated steel or heavy aluminum alloy).

14. How many mounting holes are on the flange? There are four mounting holes evenly spaced at 90-degree intervals around the flat flange.

15. Is this a flexible coupling? No, this is a completely rigid flange coupling. It will not flex to accommodate shaft misalignment.

16. Can I use this to mount a robot wheel? Absolutely. Flange couplers are the industry standard for mounting custom plates, gears, or robot wheels to motor shafts.

17. Will this fit a standard NEMA 17 stepper motor? Standard NEMA 17 motors usually have a 5mm shaft, so this will be too large. This is designed for NEMA 23 stepper motors or geared DC motors that utilize an 8mm shaft.

18. Can it mount to D-profile shafts? Yes, it works exceptionally well with D-shafts. Ensure you align one of the set screws so it presses flat against the flat portion of the D-shaft for maximum hold.

19. Can I mount a pulley to this flange? Yes, as long as the pulley has a matching mounting hole pattern (24mm diagonal pitch) or can be custom-drilled to match.

20. Do I need to use threadlocker on the set screws? While not strictly required, using a mild threadlocker (like blue Loctite) on the set screws is highly recommended for robotics or high-vibration applications to prevent them from vibrating loose over time.