12mm Rigid Metal Flange Shaft Coupling - Motor Hub Connector with M4 Set Screws

Specifications

• Inner Hole Diameter (d): 12mm

• Cylinder Outer Diameter (d1): 18mm

• Base Outer Diameter (D): 32mm

• Total Height (H): 13mm

• Cylinder Height (h1): 10mm

• Base Thickness (h2): 3mm

• Mounting Hole Distance (L): 24mm (diagonal)

• Mounting Hole Size (d2): 4mm / M3 compatible

• Set Screw Hole Size (d3): M4

Key Applications and Projects

• Heavy-Duty Robotics: Bolting large Mecanum or Omni-directional wheels directly to the 12mm shafts of powerful planetary gear motors.

• CNC Rotary Axes: Attaching a flat aluminium build plate or rotary chuck to a large stepper motor for a DIY 4th-axis CNC attachment.

• Custom Winches: Creating a spooling mechanism by bolting a custom 3D-printed drum to the flange to lift heavy payloads.

Unlock New Capabilities (Project Evolution)

• The All-Terrain Rover Base: Standard robot wheels often snap under heavy loads. Evolve your robotics project by pairing four of these 12mm flange couplings with high-torque Planetary Gear Motors and 8-inch Pneumatic Rubber Tires. By bolting the wheels directly to the flange faces, you distribute the weight away from the shaft tip, creating an industrial-grade, all-terrain rover capable of carrying significant payloads across rough outdoor environments!

Package Includes:

• 1 x 12mm Rigid Metal Flange Coupler

• 2 x M4 Set Screws (Grub Screws)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What size motor shaft does this fit? It is machined precisely to fit standard 12mm diameter motor shafts.

2. What is the overall diameter of the flat base? The flanged base has an outer diameter of 32mm.

3. How tall is the entire coupler? The total height is 13mm (which includes the 3mm thick base and the 10mm tall cylinder).

4. How does it attach to the motor shaft? It utilizes two M4 set screws (included) on the side of the cylinder that tighten down and grip the motor shaft.

5. What size screws do I need for the four mounting holes on the base? The holes are 4mm in diameter, making them perfectly sized for M3 or M4 machine bolts.

6. What is the diagonal distance between the mounting holes? The diagonal center-to-center distance between the mounting holes is 24mm.

7. What material is this made from? It is constructed from a rigid, non-corrosive metallic alloy (typically aluminum or a hardened zinc alloy).

8. Does it come with the set screws? Yes, two black M4 grub screws are included in the package.

9. Does it come with the hex key to tighten the screws? No, you will need to provide your own standard metric hex key (Allen wrench).

10. Can I use this to connect two 12mm shafts end-to-end? No, this is a "flange" coupling meant to connect a single shaft to a flat surface or a wheel. If you need to join two shafts together, you need a standard cylindrical shaft coupler.

11. Is this a flexible coupling? No, it is 100% rigid. It will not absorb vibrations or compensate for shaft misalignment.

12. Will this fit a standard NEMA 17 stepper motor? No. Standard NEMA 17 stepper motors typically have 5mm shafts. You would need a 5mm version of this flange. This is for much larger 12mm shafts.

13. What does "flange" mean? The flange is the flat, disc-like base with the four holes. It provides a wide surface area to distribute load when surface-mounting.

14. Do I need a motor with a flat spot (D-shaft)? While it works on perfectly round shafts, a motor with a D-shaft (a flat spot) is highly recommended. It gives the set screws a flat surface to bite into, ensuring zero slippage under extreme torque.

15. How many of these do I need for a 4-wheel robot? You will need one flange coupling for each driven wheel on your robot (so, four couplings for a 4WD rover).

16. Can it handle high torque? Yes, because it is made of solid metal and uses dual set screws, it is designed specifically for high-torque power transmission in robotics and light industrial machines.

17. What is the outer diameter of the middle cylinder? The cylindrical collar portion has an outer diameter of 18mm.

18. Is the inside of the 12mm hole threaded? No, the main 12mm center bore is completely smooth to allow the motor shaft to slide in easily.

19. Can I use this for a DIY steering wheel for a racing simulator? Yes! It is an excellent piece of hardware for bolting a real steering wheel rim to a 12mm steering column or force-feedback motor shaft.

20. Can I use this outdoors? Yes, the metal body is resistant to standard environmental moisture, but you should apply a drop of machine oil to the black set screws to prevent them from rusting over time.