LH Stinger is a cartesian FDM printer built for 400 to 600 mm/s daily printing

A design, not a product

LH Stinger is described as a no-compromise cartesian 3D printer designed for speed and precision, created as a long-lasting platform for those who like to push quality and speed to the extreme, and the readme marks it as a community-driven project.

That framing decides what the repository is. It is not a manufacturer's product page with a download button for a manual. It is a set of design files, and the top level listing shows what that means in practice. There is a CAD/ directory with the CAD source files, an STL/ directory with the printed parts and their printing instructions, a DXF/ directory for the bed drawings, a PCB/ directory with the electronics designs, a Config/ directory with the Klipper configuration and the slicer profiles, a KITS/ directory, a User_Mods/ directory for the modifications people have made, and an Images/ directory.

The status is V1.0, and the release list shows the shape of getting there. LHS-R1.0 on 2024-08-25, LHS-R1.0RC on 2024-08-12, and LHS-R1.0B2 on 2024-01-29. The last push to the repository was on 2026-09-30, so the design is still being worked on after the 1.0 release.

The licence is recorded as a custom one that GitHub cannot classify, so the terms are in the LICENSE.md file, and there is a FUNDING.yml file, which is where the project's GitHub sponsorship accounts are configured.

The frame is six extrusions and a low centre of gravity

The frame design is the foundation everything else sits on, and the readme is specific about it.

The design is a cross frame focused on stiffness and stability with a low centre of gravity, with a streamlined frame assembly consisting of only six extrusions. It is built using 30 series T-slotted extrusions, with parts up to 3090, and all bracket assembly.

Six extrusions is a small number, and it is a design decision rather than an omission. A printer that has to accelerate a 235 millimetre bed at 20,000 millimetres per second squared has to resist the reaction force, and the way to do that is to make the structure a closed shape with few joints, rather than a loose gantry that flexes. The cross shape is what stops the frame from twisting, and a low centre of gravity is what keeps it from rocking when the Y axis slams into a stop.

The build volume is 235 by 235 by 200 millimetres at maximum, and the readme notes it is easily expandable to other sizes. There are two bed configurations, a 200 millimetre square carbon fibre bed for the high speed setup and a 235 millimetre square bed support for the larger volume.

The bed itself is supported by a lightweight carriage assembly with carbon fibre components, a rigid carbon fibre bed mount, and a lightweight dual plate carbon fibre bed carriage with an integrated tensioner that is compatible with different bed sizes and carriage configurations.

The printer is also designed to be enclosed, with the main electronic components outside of the build chamber, and the 200 millimetre bed configuration can be fully enclosed up to the frame bounding box with no extra space needed for the bed movement.

The numbers the design is built around

The feature list is written around performance figures, and it is worth reading them as design constraints rather than as claims.

The daily print speed target is 400 to 600 millimetres per second with 20,000 millimetres per second squared of acceleration, and the readme links three tests for it. The motion system is capable of 1,000 millimetre per second with 100,000 millimetres per second squared, which is the limit rather than the working point. The maximum volumetric flow rate is about 55 to 60 cubic millimetres per second.

Those three numbers describe a printer for large, fast prints. 600 millimetres per second is a speed where the limiting factor is usually the hotend's melt rate rather than the motion system, which is why the volumetric figure is quoted next to it, and why the toolhead section discusses alternate hotends including the Rapido and the Goliath.

The components match the numbers. The entire motion system is based on high preload MGN12H linear guide rails, which are 12 millimetre rails, larger than the usual 9 or 10. It is fully belt-driven with minimal belt paths, using 9 millimetre 2GT belts in a symmetrical configuration for the Y-axis and 6 millimetre 2GT belts for the rest of the axis, so the Y axis, which carries the mass of the bed, gets the larger belt. The Y-axis uses an AWD stepper configuration with an optional conversion for an X-axis AWD setup, so a stepper on each side of the rail rather than one.

The steppers are high torque LDO-42STH48-2504AC motors supplied with 36 volts for the X and Y axes, and the Z axis has independent stepper motors with Z Tilt capability for the X-axis, which is a detail that matters if you want the bed to stay level as the gantry moves. Both axes use double shear shaft supports for their steppers.

Electronics in a box outside the chamber

The electronics are described with the same specificity, and the arrangement is unusual enough to be worth explaining.

The printer is driven by the Octopus Pro 1.1 board with TMC2240 drivers, running Klipper or Kalico firmware, and a fully featured Klipper configuration with slicer profiles is available in the Config directory.

The power is a dual power supply supporting 24V and 36V standards, and the readme says it is easily configurable for 48V.

The structural decision is the external electronic box, which is described as easily serviceable with good airflow, and it supports multiple power supplies, SSRs, a Raspberry Pi and large controller boards. The reason for putting the electronics outside the build chamber is heat. A 200 watt bed heater and a chamber that can be fully enclosed make the inside of the printer a hostile place for a stepper driver, and the box is the answer to that.

Cable management is handled by a quick disconnect breakout board between the printer and the box, and the board is named the LHS Breakbeat in the kit highlights, which is the name the distribution board goes by.

The heating side is a lightweight polyimide flex PCB 200 watt bed heater, and the part cooling is a dual 5015 fan setup for part cooling plus dual auxiliary cooling modules based on 9733 blower fans providing 64 CFM of auxiliary cooling. The auxiliary figure is large, and it is what a high speed print needs, since the time available for the layer to cool is measured in seconds.

Toolhead, extruder and probe

The toolhead is based on the Dragon HF hotend with an HF extender, and the readme is generous about alternatives, listing the Dragon UHF, Ace, Mellow NF-Crazy-Volcano HF, Rapido and Goliath as supported alternate hotends, with the user modifications for them in a User_Mods directory.

That list is really a menu of melt rates. A printer that targets 55 to 60 cubic millimetres per second needs a hotend that can deliver it, and the range from the Dragon HF to the UHF to the Rapido is a range of how much plastic each one can push before the melt rate becomes the limit. Since the extruder is a direct drive LDO Orbiter 2.5 with a Sherpa Mini also supported, the hotend and the extruder can be swapped independently, which is a useful property when you are tuning for a specific material.

The probe is the Annex Engineering Quickdraw, and the two reasons given for it are about geometry rather than about the sensor itself. Zero Y offset probe placement for no gantry twist deviation, and full bed probe coverage.

The printed parts are described as minimalistic and focused on strength and easy printability, and they are printed in ASA for high temperature resistance, which is the right material for a printer that is designed to be run hot and fast.

The bed heater and the carbon fibre bed are also the parts of the design most likely to need replacing, since a flex PCB heater is a consumable, and the DXF directory exists so you can cut a different bed size.

Two ways to get one, and what you still have to supply

There are two routes to a printer, and the readme is clear that one of them does not remove the work.

The first is to source it yourself, following the BOM guide, which is a spreadsheet. The second is an official upgraded LH Stinger Rev2 kit, produced and sold by FYSETC. The readme notes that a portion of every kit sale goes towards supporting the project, and gives the discount code FYSBKSALELH for a total of 699 dollars with free shipping from the US or the EU.

The kit highlights are worth reading closely, because the Rev2 kit is not simply the base design in a box. It ships a Phaetus Dragon UHF hotend, an FYSETC Sherpa Mini CNC extruder, MGN 12H Z1 preload linear rails, an FYSETC Spider V3.0 H7 board running at 550 megahertz, 48 volt power with TMC5160 drivers for the AWD Y and X axes, high torque 2.5 amp 580 millinewton metre steppers with 30 millimetre shafts for double shear support, and Delta and Meanwell power supplies. The bed is a carbon fibre bed with a pre-applied PI heater and a pre-epoxied carriage assembly, and the LHS Breakbeat distribution board and wiring harness are included.

The Rev2 kit therefore differs from the base design in the hotend, the extruder, the controller board and the drive electronics, which is worth knowing before you compare a kit price against a self-sourced bill of materials.

And there is a line in bold in the kit section that decides the real cost of the kit route. You require the printed parts and a BTT Pi V1.2 or a Raspberry Pi single board computer as the Klipper host. So even with the kit, you still print the parts and you still provide the board.

The project is sponsored by JLCPCB Flexible Heaters, which provides custom flex heaters for the build.

What the repository gives you to work from

The Resources section lists the artefacts a builder actually needs, and together they are a complete package for constructing the machine.

The Assembly Guide is in the project wiki, the STL files and printing instructions are in the STL directory, the CAD source files are in the CAD directory, the Klipper configuration is in the Config directory, and the Build Log is a wiki page, which is where the assembly decisions and their consequences get written down.

Two directories are worth calling out because they change what the design is. User_Mods holds the modifications people have made, and the readme points at it for the alternate toolheads and for the Sherpa Mini extruder, so the community's own experiments are part of the official resource set rather than scattered across forum posts. And the KITS directory is the packaging side, which is where the parts a commercial kit contains get enumerated.

There is also a DXF directory for the bed drawings, which matters if you want a different bed size, since the design allows expansion beyond the standard 235 and 200 millimetre configurations, and a PCB directory for the electronics designs, which includes the bed heater flex PCB and the breakout board.

The resonance test images for the X and Y axes are in the Images directory, and the readme includes them under the features, which is a sensible inclusion for a high speed design: the frame's response to a given input frequency is what decides whether a print at 600 millimetres per second is clean or ringing, and publishing the measurements lets somebody else check the claim on their own build.

Editorial conclusion

Adopt the LH Stinger design if you are comfortable sourcing a printer from a bill of materials and configuring Klipper yourself, since the repository gives you every artefact needed and the money saved goes into parts rather than a manufacturer's margin. Do not adopt it if you want a plug and play machine, because the official kit still requires printed parts and a Raspberry Pi or BTT Pi single board computer that you provide. Verify first which revision of the bill of materials the instructions in the repository match, and read the Kit Highlights list, because the Rev2 kit swaps in different hotend, extruder, board and power supply parts from the base design.

Frequently asked questions

Official sources

1. Issues
2. lhndo/LH-Stinger on GitHub
3. README
4. Releases