Description
Rigid couplings for 3D printers provide a direct, solid connection between a stepper-motor shaft and a lead screw when both shafts can be aligned accurately. This product family is intended for compact motion systems where a rigid shaft connection is preferred over a flexible coupling.
Two bore combinations are available: 5 mm to 8 mm for connecting a typical 5 mm motor shaft to an 8 mm lead screw, and 8 mm to 8 mm for joining two 8 mm shafts. Both listed variants have a 20 mm outside diameter and a 25 mm overall length according to the supplier data already assigned to this product.
Product family SKU: 1072100
Dimensions and Available Variants
The drawing and technical table below show the dimensions and bore combinations for the two available rigid coupling variants.
| Model | Length L | Diameter D | Bore d1 | Bore d2 | SKU |
| 3D-Printer-Coupling-5-8-V1 | 25 mm | 20 mm | 5 mm | 8 mm | 1072101 |
| 3D-Printer-Coupling-8-8-V1 | 25 mm | 20 mm | 8 mm | 8 mm | 1072102 |
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| All product data (pictures, dimensions, tables, drawings) are provided as received from the supplier; we exclude liability for their accuracy or completeness. | |||||
Rigid Connection for Precise Shaft Alignment
A rigid coupling creates a solid mechanical link between two coaxial shafts. Unlike flexible coupling designs, a rigid coupling is not intended to absorb radial, angular or axial misalignment. Correct alignment is therefore important during assembly, especially when the motor shaft is connected directly to a lead screw.
- Direct shaft connection: connects the stepper-motor output shaft directly to the lead screw in compact 3D-printer motion systems.
- High torsional rigidity: the rigid connection reduces elastic twist compared with flexible coupling types.
- Two bore combinations: choose 5-to-8 mm or 8-to-8 mm according to the shafts used in the machine.
- Compact envelope: both variants use a 20 mm outside diameter and 25 mm overall length.
- Alignment-sensitive design: use only where the connected shafts can be positioned accurately on the same axis.
Typical 3D Printer Installation
The example below illustrates the intended application: a stepper motor and lead screw connected directly through the rigid coupling.
Before tightening the coupling, align the motor shaft and lead screw as closely as possible. A rigid coupling should not be used to force two offset or angled shafts into line, because the resulting side load can be transferred to the motor and screw support bearings.
How to Select the Correct Bore Size
Select the variant by measuring the diameter of both shafts that will be connected. The bore on each side must match its corresponding shaft diameter.
| Connection requirement | Recommended variant | SKU |
|---|---|---|
| 5 mm motor shaft to 8 mm lead screw | 3D-Printer-Coupling-5-8-V1 | 1072101 |
| 8 mm shaft to 8 mm shaft | 3D-Printer-Coupling-8-8-V1 | 1072102 |
Rigid vs Flexible Couplings
Rigid and flexible couplings solve different mechanical problems. A rigid coupling is appropriate when the shafts are accurately aligned and the goal is a stiff, direct connection. A flexible coupling is more suitable when the assembly requires limited compensation for shaft misalignment. For a rigid coupling, precise installation alignment remains essential.
FAQ frequently asked questions
Which variant should I use for a 5 mm stepper shaft and 8 mm lead screw?
Use model 3D-Printer-Coupling-5-8-V1, SKU 1072101.
Can this rigid coupling compensate for shaft misalignment?
No. Rigid couplings are intended for shafts that are aligned on the same axis and should not be used as a misalignment-compensating element.
What are the overall coupling dimensions?
Both listed variants are 25 mm long with a 20 mm outside diameter according to the supplier data on this product page.
When should I choose a flexible coupling instead?
Choose a flexible design when the machine requires limited compensation for angular, radial or axial shaft misalignment rather than a fully rigid shaft connection.
