Using the HT Hotend

The HT Hotend is a high-temperature hotend. Its main benefit is enabling nozzle temperatures up to 400°C and offering broader material compatibility than the standard hotend configuration.

It is compatible with the following printers:

• CORE One
• CORE One+
• CORE One+ (Gen 2)
• CORE One L
• CORE One L+

General use recommendation

• The HT hotend can't be used with the standard Prusa Nozzle, high-flow nozzles, or standard Obxidian nozzles. Use it only with the compatible E3D ObXidian Standard Flow 500 nozzles in 0.4 mm or 0.6 mm diameters. 
• Do not exceed 30% print cooling fan power unless a specific, validated material profile explicitly permits a higher setting.
• For high-temperature polymers, start with the filament manufacturer's recommended parameters and tune only as needed, in small increments.
• Always operate the printer in a well-ventilated area with filaments appropriate for the intended application.
• Avoid contact between bare skin and the heater block. Natural skin oils adhere to the block and bake on at high temperatures, degrading heatblock performance. If touched accidentally while cold, clean the block thoroughly with a dry paper towel before heating.

Starting procedure

When the HT hotend is installed, the printer will briefly heat up the nozzle to detect whether it is a regular or HT hotend.

• Select the correct printer profile and matching nozzle diameter (0.4 mm or 0.6 mm) in PrusaSlicer.
• Always apply a filament profile specifically matched to the HT Hotend and the material being used.
• Properly dry and store hygroscopic filaments (such as the PA/nylon family) according to the manufacturer's recommendations before loading.
• Perform the Gearbox alignment required by the printer, and confirm the hotend upgrade menu prompt on initial start-up.
• Closely monitor the initial extrusion and first layers of your print to confirm smooth melting and stable temperature control.

Idler and hotend for each material

The HT Hotend Upgrade assembly kit also includes a new set of idlers. Each is intended for a different material type.

• Marked S: standard idler, has two bearings.
• Marked H: modified idler for more demanding materials, has one bearing.

For best results, we recommend installing the appropriate idler before each print according to the table below.

Installing the idler

After installing the HT hotend using the assembly guide, it will be possible to switch between the idlers without disassembling the extruder. For that, just open the idler and detach it from the tubular spacer.

Note that the screw head must face the front of the Nextruder.