Positron 90 Degree Hot End

LDO Positron V3.2 90° Hotend Kit — Custom Phaetus 90-Degree V6 Hotend, Bimetallic Heatbreak, 75W Heater, 0.4mm Nozzle

The Positron V3.2 90° Hotend is the only hotend that exists specifically for the Positron V3.2 — a custom assembly manufactured by Phaetus for LDO that bends the entire filament path and nozzle exit at a 90-degree angle. This geometry is not an afterthought: the Positron prints upside down, with the toolhead at the base and the bed suspended above it. A conventional vertical nozzle exit would collide with the Positron's inverted kinematics. The 90° exit allows the nozzle to point upward toward the glass bed while the toolhead moves in XY below it — the physical prerequisite for the entire Positron concept to function. If you need a replacement or are building a Positron V3.2 from BOM, this is the only correct hotend.

⚠️ Positron V3.2 only. This hotend is not compatible with any other printer. The 90° exit geometry has no application outside the Positron's inverted printing architecture.
⚠️ Hot tightening required. Always perform final nozzle tightening at operating temperature to prevent leaks between nozzle and heatblock.
⚠️ Max temperature: 260°C. Designed and rated for PLA and PETG on the Positron platform. Verify hotend temperature limits in your Klipper config before attempting higher-temp materials.

Why the Positron Needs a 90° Hotend — The Engineering Behind It

Every other FDM printer in existence points its nozzle downward — gravity assists the extrusion and the bed is below. The Positron inverts this: the toolhead is on the base plate, the gantry folds over it, and the transparent ITO glass bed hangs above the toolhead. The nozzle prints upward into the glass. To achieve this while keeping the heater block, heatbreak, and cold end in a practical orientation, Phaetus designed this hotend with a 90° bend at the V6-style nozzle exit — the filament enters vertically from the bowden tube, transitions through the 90° heatblock, and exits horizontally toward the glass bed above. It's mechanically unusual, thermally demanding to design correctly, and entirely unique to this printer.

75W Heater — Oversized Power for Consistent Melt-Zone Performance

The Positron's 90° heatblock geometry creates a longer thermal path from heater to nozzle tip than a straight heatblock — more metal to heat through the bend. The solution is a 75W heater cartridge, significantly more powerful than the 40W or 60W heaters in most consumer hotends. The higher wattage compensates for the thermal path length and ensures the melt zone reaches and holds target temperature quickly even during sustained high-speed printing at the Positron's rated 250mm/s. Fast heat-up, stable temperature under load.

Bimetallic Heatbreak — Sharp Thermal Gradient Through the Bend

Managing heat creep through a 90° bend is more challenging than in a straight hotend — the heatbreak has to maintain a sharp thermal transition at the curve without creating a stress concentration point. This hotend uses a bimetallic heatbreak that combines a stainless steel inner tube (low thermal conductivity, resists heat migration) with a copper or aluminum outer body (high conductivity, efficient heatsink coupling). The design is optimized with finite element analysis to achieve the steepest possible temperature gradient at the transition zone — keeping the cold end cold and the melt zone hot for clog-free operation.

V6-Style Nozzle — 0.4mm Included, Standard Ecosystem

Despite its unusual exit angle, the Positron hotend uses a standard V6-thread nozzle at the tip — meaning your existing library of V6-compatible nozzles (brass, hardened steel, plated copper) is directly usable. A 0.4mm nozzle is included in the kit to get you printing immediately. Nozzle changes follow the same procedure as any V6 hotend — with the standard hot-tightening step required for a leak-free seal.

Specifications

What's Included

When Do You Need This?

If you're building a Positron V3.2 from BOM, this is a required component — there is no substitute. If you're replacing a damaged or failed hotend on an existing Positron, this is the only correct replacement. Because the 90° exit geometry is unique to this printer and manufactured in limited quantities by Phaetus specifically for the Positron platform, keeping a spare on hand is worth considering if the Positron is your primary travel machine.

Resources

• Positron Wiki — official build documentation, hotend installation, Klipper config
• LDO Positron V3.2 Assembly Guide — hotend mounting and wiring

Browse all Positron V3.2 spare parts and accessories at 3D Printer Hotends, or explore all motion and toolhead upgrades at 3D Printer Upgrades.