- Stock: 419
- Model: Special-Hardware-Set
Special hardware set intended for assembling a Prusa i3 Rework 3D printer. It includes the spring-loaded screws used by the extruder tensioning system, set screws for the idler arrangement and small wheel, and M5 polymer nuts for the Z-axis movement system.
This product brings together several less common components that may be difficult to source individually. It is not the complete printer hardware kit: it is designed to complement the general fasteners and corresponding printed parts.
Kit contents
- 2 × partially threaded M3 × 40mm screws with springs.
- 1 × M8 × 20mm stud or set screw for the extruder idler.
- 1 × M3 × 10mm stud or set screw for the small extruder wheel.
- 2 × M5 polymer or nylon nuts for Z-axis movement.
The M5 nuts may be supplied in white or black depending on the available production batch. The photograph shows the components assembled with their corresponding auxiliary pieces; presentation may vary.

Purpose of each component
- M3 × 40mm spring-loaded screws: provide adjustable pressure for the extruder drive system.
- M8 × 20mm set screw: used by the extruder idler arrangement provided by this design.
- M3 × 10mm set screw: used to mount the small wheel.
- M5 polymer nuts: form part of the Z-axis movement system in this configuration.
Compatibility
The kit is prepared for the Prusa i3 Rework design used by HTA3D. It complements the complete Prusa i3 Rework hardware set and the Prusa i3 Rework printed-parts kit.
The Prusa i3 family includes many revisions, adaptations and different extruder designs. Therefore, compatibility with every printer described as a Prusa i3 should not be assumed without checking:
- The printed-part revision.
- The installed extruder design.
- The thread used by the Z-axis rods or lead screws.
- The position and purpose of every fastener in the assembly.
The included M5 nuts are not compatible with T8 trapezoidal lead screws or systems using a different thread.
Not included
- The printer’s general hardware set.
- Printed parts.
- Rods, lead screws or bearings.
- Extruder motor, gears or pulleys.
- Assembly tools.
Assembly recommendations
- Identify the printer and printed-part revision before starting assembly.
- Do not overtighten the spring-loaded screws: the pressure should provide reliable filament drive without deforming the filament or printed parts.
- Make sure the set screws do not protrude into moving areas.
- After fitting the M5 nuts, check that the Z axis moves freely without binding.