4.0 KiB
Klipper is a 3d printer firmware with several compelling features:
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High precision stepper movement. Klipper utilizes an application processor (such as a low-cost Raspberry Pi) when calculating printer movements. The application processor determines when to step each stepper motor, it compresses those events, transmits them to the micro-controller, and then the micro-controller executes each event at the requested time. Each stepper event is scheduled with a precision of 25 micro-seconds or better. The software does not use kinematic estimations (such as the Bresenham algorithm) - instead it calculates precise step times based on the physics of acceleration and the physics of the machine kinematics. More precise stepper movement translates to quieter and more stable printer operation.
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Best in class performance. Klipper is able to achieve high stepping rates on both new and old micro-controllers. Even an old 8bit AVR micro-controller can obtain rates over 175K steps per second. On more recent ARM micro-controllers, rates over 450K steps per second are possible. Higher stepper rates enable higher print velocities. The stepper event timing remains precise even at high speeds which improves overall stability.
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Configuration via simple config file. There's no need to reflash the micro-controller to change a setting. All of Klipper's configuration is stored in a standard config file which can be easily edited. This makes it easier to setup and maintain the hardware.
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Portable code. Klipper works on both ARM and AVR micro-controllers. Existing "reprap" style printers can run Klipper without hardware modification - just add a Raspberry Pi. Klipper's internal code layout makes it easier to support other micro-controller architectures as well.
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Simpler code. Klipper uses a very high level language (Python) for most code. The kinematics algorithms, the gcode parsing, the heating and thermistor algorithms, etc. are all written in Python. This makes it easier to develop new functionality.
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Advanced features:
- Klipper implements the "pressure advance" algorithm for extruders. When properly tuned, pressure advance reduces extruder ooze.
- Klipper also implements a novel "stepper phase endstop" algorithm that can dramatically improve the accuracy of typical endstop switches. When properly tuned it can improve a print's first layer bed adhesion.
- Support for limiting the top speed of short "zig-zag" moves to reduce printer vibration and noise. See the kinematics document for more information.
To get started with Klipper, read the installation guide.
Common features supported by Klipper
Klipper supports many standard 3d printer features:
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Works with Octoprint. This allows the printer to be controlled using a regular web-browser. The same Raspberry Pi that runs Klipper can also run Octoprint.
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Standard G-Code support. Common g-code commands that are produced by typical "slicers" are supported. One may continue to use Slic3r, Cura, etc. with Klipper.
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Constant speed acceleration support. All printer moves will gradually accelerate from standstill to cruising speed and then decelerate back to a standstill.
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"Lookahead" support. The incoming stream of G-Code movement commands are queued and analyzed - the acceleration between movements in a similar direction will be optimized to reduce print stalls and improve overall print time.
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Support for cartesian, delta, and corexy style printers.
Step Benchmarks
Below are the results of stepper performance tests. The numbers shown represent total number of steps per second on the micro-controller.
| Micro-controller | 1 stepper active | 3 steppers active |
|---|---|---|
| 20Mhz AVR | 177K | 117K |
| 16Mhz AVR | 140K | 93K |
| Arduino Due (ARM) | 462K | 406K |