Motor shaft does not fit your gearbox? Get a custom coupling, quoted within 48 hours.

+91 76982 63509

Custom couplings for any motor, gearbox or robot joint

Motor shaft does not fit your gearbox? Gearbox output does not match your joint or housing? Tell us both sizes and we machine the coupling or adapter flange that joins them, bored to each side.

  • Any ID/OD mismatch: different diameters, key, D-cut, spline, inch to metric
  • Motor to gearbox, motor to joint, gearbox to joint or housing
  • 2D proposal and quote within 48 working hours, from one piece
MotorGearboxMotor shaft Ø14Gearbox input Ø19Custom coupling Ø14 ↔ Ø19
Example: a 14 mm motor shaft and a 19 mm gearbox input. The coupling (yellow) is bored to each shaft.

What do you want to connect?

Pick the case that looks like yours. Each coupling is made to your two sizes, so it does not matter whether the parts came from us.

MotorGearboxMotor shaft Ø14Gearbox input Ø19Custom coupling Ø14 ↔ Ø19

Motor to gearbox coupling

Your servo or stepper shaft does not fit the gearbox input.

We make: A coupling bored to the motor shaft on one side and the gearbox input on the other, plus an adapter flange if the mounting faces differ.

Quote this coupling
MotorJointMotor shaft Ø11Robot joint bore Ø16Custom coupling Ø11 ↔ Ø16

Motor to robot joint coupling

You drive a joint, wheel or axis directly and the motor shaft does not match its bore.

We make: A coupling or bore adapter that takes the motor shaft into your joint, hub or pulley.

Quote this coupling
GearboxHousingGearbox output Ø22Housing bore Ø30Custom coupling Ø22 ↔ Ø30

Gearbox to joint or housing coupling

The gearbox output shaft or flange does not match the joint, housing or load you connect to.

We make: An output coupling or adapter flange sized to the gearbox output and to your part.

Quote this coupling
Shaft Ø6.4Shaft Ø8Custom coupling Ø6.4 ↔ Ø8

Shaft size adapter (ID/OD mismatch)

Two shafts of different diameter, key type or unit (inch and metric) need to turn together.

We make: A coupling, sleeve or bush with a different bore on each side: smooth, keyed, D-cut or clamped.

Quote this coupling

Shaft or bore does not match? Find your fix

The most common mismatches we solve. Sizes are examples; we work to yours.

ExampleThe mismatchWhat we make
Motor shaft Ø14 mm, gearbox input Ø19 mmDifferent shaft diameters (OD)Coupling bored 14 mm on one side and 19 mm on the other
Motor shaft Ø8 mm, joint or pulley bore Ø12 mmShaft smaller than the bore (ID)Bore adapter sleeve or bush, or a coupling to your hub
Stepper shaft 6.35 mm (¼ in), gearbox Ø8 mmInch shaft to metric boreInch-to-metric coupling
Keyed motor shaft, smooth gearbox shaftDifferent shaft typesKeyway on one side, clamping bore on the other; D-cut and spline too
Motor pilot Ø50 mm, gearbox input face for Ø70 mmMounting face does not matchAdapter flange with your pilot and bolt circle on each face
Gearbox output flange PCD 58 mm, joint PCD 80 mmOutput does not match the joint or housingOutput adapter flange or coupling
Shafts too far apart or too closeAxial gap or overlapCoupling or spacer made to the length you need

How to measure for a coupling

A motor model number or a drawing is often enough. If you measure, these six sizes cover a coupling and an adapter flange. Measure the other part (gearbox, joint or housing) the same way; for a bore, give its inner diameter and depth.

A
Shaft diameter (OD) with a caliper, in mm or inch
B
Shaft length that sticks out of the face
C
Shaft type: key width, flat (D-cut) depth, or spline
D
Pilot (spigot) diameter of the round step on the face
E
Bolt circle (PCD), centre to centre across two opposite holes
F
Bolt hole size and whether it is tapped or through
ABCDSideEFDFront

Couplings, flanges and housings we make

Custom shaft couplings

One-piece couplings with a different bore on each side: clamping, keyed, D-cut or splined, in metric or inch sizes. Motor to gearbox, motor to joint, gearbox to load.

Motor adapter flanges

Adapter plates with pilot, bolt circle and bolt holes machined to your servo or stepper on one face and the gearbox or housing on the other.

Output adapters

Output flanges, shafts and hollow-bore adapters so a gearbox bolts straight to your robot joint, pulley, pinion or wheel hub.

Housings and brackets

Foot mounts, joint housings and motor brackets in aluminium or steel, made to your drawing.

Get your custom coupling quoted

Enter the two sizes and watch the coupling drawing update. Add a drawing or motor model if you have one.

MotorJointMotor shaft Ø11Robot joint bore Ø16Custom coupling Ø11 ↔ Ø16
Coupling bored Ø11 mm on one side and Ø16 mm on the other.
  1. Send both sizes or a drawingThis form. A motor model often covers one side.
  2. We confirm the design2D proposal and quote within 48 working hours.
  3. We machine and fit itChecked against your sizes before dispatch.
What are you connecting?
mm
mm

Inch sizes: 1/4 in = 6.35 mm, 3/8 in = 9.525 mm, 1/2 in = 12.7 mm.

What do you need?
Motor, gearbox and mounting optional
mm
mm
    Your details

    Files are stored privately and used only to quote and make your parts.

    Custom coupling questions

    How do I connect a motor shaft to a gearbox with a different bore size?

    Use a coupling with a different bore on each side. We machine the coupling to your motor shaft diameter on one side and the gearbox input shaft or bore on the other, for example 14 mm to 19 mm, with a clamp, key or D-cut to suit each shaft.

    Can you make a coupling to connect a motor directly to a robot joint or housing?

    Yes. Send the motor shaft size and the bore, hub or flange of the joint or housing, or a drawing of both. We make the coupling or adapter that joins them.

    Can you connect a gearbox output to my joint, pulley or housing?

    Yes. We make output couplings and adapter flanges that match the gearbox output shaft or flange on one side and your part on the other.

    What do I need to measure for a custom coupling?

    For each shaft: the diameter, the usable length and the type (smooth, keyed with key width, D-cut, spline). For a bore: its inner diameter and depth. For a mounting face: the pilot diameter, bolt circle (PCD) and bolt size. A motor model number or a PDF/STEP drawing is often enough.

    Do you make inch-to-metric couplings?

    Yes. Couplings can be bored to inch shafts such as 1/4 in (6.35 mm) on one side and metric sizes such as 8 mm on the other.

    Can I order a single custom coupling?

    Yes. There is no minimum order quantity. We make single couplings and flanges for prototypes and batch quantities for production.

    Which files can I upload?

    PDF, DWG, DXF, STEP/STP, IGES, Parasolid (X_T), SolidWorks part files, ZIP archives and photos (JPG, PNG, WEBP), up to 25 MB each. Files are stored privately.