Ships Marlin 2.0 (LGT board); Klipper only after you install it.
Source
Doesn't ship with Klipper: it runs Klipper after you install it in place of its own firmware, a modification
What works with SimplyPrint
Connected through OctoPrint, SimplyPrint is expected to support everything the Longer LK4 lets other software do: the camera and AI failure detection, remote printing, temperature and movement control and AutoPrint. 3 features depend on how it's set up: the table says what each needs.
Every SimplyPrint feature, for each way of connecting it to SimplyPrint
Connected to SimplyPrint through
SimplyPrint feature
OctoPrint
Expected to work
Monitoring
Live status and progress
Yes
Webcam
Yes1
AI failure detection
Yes1
Time left
Yes
Layer progress
Yes
Temperatures
Yes
Printing
Starting a print
Yes
Pause, resume and cancel
Yes
Skip objects
Depends2
Files
Print binary G-code (.bgcode)
Depends3
Printer control
Change temperatures
Yes
Moving with the controls
Yes
Homing
Yes
Extrude and retract
Yes
Change print speed
Yes
Fan speed
Yes
Baby stepping
Yes
Send G-code
Yes
Calibration
Change filament
Yes
Bed leveling
Yes
Z-Offset Calibration
Yes
Automation
AutoPrint
Pro
Yes
Download the file before the print starts
Depends4
Connected to SimplyPrint through OctoPrint
Expected to work
Monitoring
Live status and progressYes
WebcamYes1
AI failure detectionYes1
Time leftYes
Layer progressYes
TemperaturesYes
Printing
Starting a printYes
Pause, resume and cancelYes
Skip objectsDepends2
Files
Print binary G-code (.bgcode)Depends3
Printer control
Change temperaturesYes
Moving with the controlsYes
HomingYes
Extrude and retractYes
Change print speedYes
Fan speedYes
Baby steppingYes
Send G-codeYes
Calibration
Change filamentYes
Bed levelingYes
Z-Offset CalibrationYes
Automation
AutoPrint ProYes
Download the file before the print startsDepends4
Works
Depends
Not supported
Needs a camera
Requires the OctoPrint plugin Cancel Objects
Requires the OctoPrint plugin BGCode
Requires version 4.2.0 or newer of the SimplyPrint plugin
What slicer to use for the Longer LK4
None of the slicers in SimplyPrint's cloud has a ready-made profile for the Longer LK4, but it takes standard G-code: start from a similar printer's profile and set the bed size, height and nozzle to match.
We only list slicers you can use in the SimplyPrint cloud, so there may be others for the Longer LK4.
Cloud-Based Slicer for Longer LK4
All supported slicers - directly in your browser with SimplyPrint's online cloud slicer. No installation required. Slice your Longer LK4 models from any device, anywhere in the world!
Automatic Profile Updates: Profiles are automatically checked and fetched from the slicer GitHub repositories every day, as well as from our own open-source community-driven slicer profile database. This ensures you always have access to the latest profiles.
Note: Other slicers, such as Simplify3D, ideaMaker, SuperSlicer and KISSlicer, aren't in our cloud, so we don't track their profiles. They may still work well with your Longer LK4: check the slicer's own documentation or forums for a profile. You can also contribute profiles to our open-source slicer profile database on GitHub.
The app for the Longer LK4
SimplyPrint works as the Longer LK4's app: on your phone and in any browser, with a slicer in the cloud.
There's no plate swapper or auto-ejection kit for the Longer LK4 in SimplyPrint yet, but AutoPrint can still keep it printing: once the plate is clear, it starts the next job from your queue.
Bed slingers are the easiest to automate
The Longer LK4 moves its bed back and forth, so its plate comes out to the front of the printer. That's what plate swappers like these use: they take the finished plate off and slide a fresh one on. Without a kit, a G-code routine can push cooled prints off with the toolhead.
Longer LK4 specifications: bed size, print height and more
Its size, temperatures, multi-material and how it connects, from the maker and our own research.
Read more by the manufacturer
Size
Build volume
220 x 220 x 250 mm
Bed type
Square
Bed size
220 x 220 mm
Max print height
250 mm
Printing
Enclosure
Open frame
Motion system
Bed slinger
Max print speed
180 mm/s
Max extruder temperature
250 °C
Has heated bed
Yes
Max bed temperature
100 °C
Number of nozzles
1
Toolheads
1
Direct drive
No
Probing tool / Auto Bed Leveling
No
Filament width
1.75 mm
Multi-material
Toolchanger or hotend changer
No
IDEX (independent dual extruders)
No
Connecting
Connectivity
USB, SD card
Prints from
microSD card
Supports serial printing
Yes
Shipped firmware
Marlin
Files and slicing
Supported file formats
G-code (.gcode, .gco, .g)
The printer
Printer manufacturer / brand
Longer
Printer model name
LK4
Made by a company from
China
Launched
2020
Disclaimer:
We strive to keep this information as current and accurate as possible, but cannot guarantee its completeness or reliability. Our data is based on user submissions and manufacturer references.
What filament can the Longer LK4 print?
Filament compatibility for the Longer LK4: the materials Longer lists for it.
Filament
Suitability
Notes
PLA
Great
On the maker's list of materials for this printer.
PETG
Great
Comfortably in range (PETG likes a ~230-250C hotend and a ~70-85C bed).
TPU & flexibles
With care
Possible, but a Bowden extruder makes flexibles harder - print slowly and prefer firmer (higher-shore) TPU.
ABS & ASA
Great
On the maker's list of materials for this printer.
Nylon (PA)
With care
Possible with care - an enclosure and very dry filament are essential.
Polycarbonate (PC)
Not ideal
Not recommended - PC needs very high hotend temps and an enclosed chamber.
Carbon-fiber & glass-filled
With care
Possible if you fit a hardened or wear-resistant nozzle - the abrasive fibers quickly wear a stock brass nozzle.
Tip: this is a general guide from the printer's specs - always check your filament's recommended settings. With SimplyPrint you can save a profile for each spool and track exactly what filament you have in stock.
Best filament for the Longer LK4
Filaments the Longer LK4 prints well, Longer's own first, then the best known.
Printers from the same maker, of a similar size, printing the same engineering materials or multi-material like it, that you can buy today. Compare up to four side by side, with their specs and how each connects.
Who makes the Longer LK4, and how open Longer leaves you: whether its printers run without its cloud, take any filament and slicer, and can be repaired. Each area is rated from public sources.
Openness: Mixed (3.4 of 5)
Mixed
Walled gardenOpen
Longer (Shenzhen Longer 3D Technology Co., Ltd.) is a Chinese maker of budget FDM and resin 3D printers, laser engravers and UV printers. Its LK series of open-frame bed slingers, up to the LK5 Pro it still sells, is aimed at beginners, and it also built the Alfawise U20 and U30 sold under another name. In 2026 it added the LK10 and LK10 Plus, which run on a Klipper board.
Headquarters:
Shenzhen, China ·
Ownership:
Shenzhen Longer 3D Technology Co., Ltd., privately held ·
Website:www.longer.net
Published Marlin source, spare parts and slicer support for the older LK line; we found no published source for the new Klipper-based LK10.
Firmware and custom firmware ●●●●●
Longer published Marlin source for the LK1, LK4 Pro and LK5 Pro on GitHub (GPL-3.0, last updated 2022) and Klipper configs for older models (updated 2024). We found no source for the LK10's Klipper firmware.
[9][10][11]
Third-party filament, slicers and parts ●●●●●
Any filament, and no Longer slicer is required: Cura ships profiles for the LK1 to LK5 Pro and OrcaSlicer for the LK10 and LK10 Plus. Longer sells nozzle kits and hotend parts; we did not confirm which third-party nozzles fit.
[12][13][6]
Repairs and spare parts ●●●●●
Longer's shop sells LK-series mainboards, touch screens, heated beds, stepper motors, extruders, fans and nozzle kits; it publishes no CAD files.
[6]
Community and documentation ●●●●●
Longer runs a download centre with firmware, slicer builds and manuals, and a GitHub account with firmware source and Klipper configs; we found no official forum.
[7][8]
Pros
Low prices for simple, beginner-oriented printers.
Marlin source published for the LK5 Pro and older models.
Spare parts sold, from mainboards to nozzles.
Profiles in both Cura and OrcaSlicer.
Cons
No published source for the new LK10's Klipper firmware.
The LK5 Pro's firmware has not been updated since February 2022.
No official forum or community documentation hub found.
Track record
2026: Longer launched the LK10 and LK10 Plus, bed slingers on a Klipper board rated up to 500 mm/s.
[3][4]
February 2022: Longer released LK5 Pro firmware V0.4.0, based on Marlin 2; in October 2026 it was still the newest LK5 Pro firmware in Longer's download centre.
[7]
November 2020: Longer published the Marlin source for the LK1, LK4 Pro and LK5 Pro on GitHub under the GPL-3.0.
[9]
Researched from 13 sources, last checked October 18, 2026. Show sources
Most likely. We expect the Longer LK4 to connect to SimplyPrint via OctoPrint, but nobody has confirmed it yet. If you have one, the setup guide shows within minutes whether it works, and your answer confirms it for everyone.
How do I connect the Longer LK4 to SimplyPrint?
Follow our step-by-step setup guide for the Longer LK4. It shows how to connect it via OctoPrint, what you need for each, and which to pick.
What slicer should I use for the Longer LK4?
Cura, PrusaSlicer and OrcaSlicer all work with the Longer LK4, and you can run any of them in SimplyPrint's online browser slicer - no install needed, on any device.
Can I use OrcaSlicer with the Longer LK4?
Yes, but OrcaSlicer has no built-in profile for the Longer LK4 that we know of: start from a similar printer's profile and set the bed size, height and nozzle to match.
What filament can the Longer LK4 print?
Longer lists PLA and ABS & ASA for the LK4.
Does the Longer LK4 work with OctoPrint or Klipper?
The Longer LK4 works with OctoPrint, and SimplyPrint connects to it through them - so you get cloud access, a queue and camera monitoring on top.
What is the Longer LK4's bed size and build volume?
The Longer LK4 has a 220 x 220 mm print bed and prints up to 250 mm tall, a build volume of about 220 x 220 x 250 mm. See the full specifications table above for bed type, temperatures and more.
When did the Longer LK4 come out?
Longer launched the LK4 in 2020.
Can the Longer LK4 eject prints automatically?
There's no kit for it that we support yet, but SimplyPrint's AutoPrint can push prints off with the toolhead, or run your own ejection G-code, and then start the next job from your queue.
Where can I buy the Longer LK4?
From Longer's own store, which has shops for everywhere else. The links on this page go to those stores; some are affiliate links, so we may earn a commission at no extra cost to you.
Affiliate disclosure: Some links on this page are affiliate links. We may earn a commission if you make a purchase, at no extra cost to you. As an Amazon Associate, we earn from qualifying purchases.
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