# Knowledge Base **URL:** https://klipper.discourse.group/c/knowledge-base/16.md [Latest](https://klipper.discourse.group/latest.md) · [Categories](https://klipper.discourse.group/categories.md) --- ## [About the Knowledge Base category / Table of Contents](https://klipper.discourse.group/t/about-the-knowledge-base-category-table-of-contents/6228)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [January 27, 2023, 6:52am UTC](https://klipper.discourse.group/t/about-the-knowledge-base-category-table-of-contents/6228 "2023-01-27T06:52:12Z")
A collection of useful Klipper know-how and tips Table of Content General Installing Klipper with KIAUH Klipper Architecture / Ecosystem Klipper Versioning, Downgrading, and Bisecting The “dirty” Flag and the Team’s P… --- ## [Klipper-mcu Service Fails to Start](https://klipper.discourse.group/t/klipper-mcu-service-fails-to-start/12219)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [December 11, 2023, 7:16pm UTC](https://klipper.discourse.group/t/klipper-mcu-service-fails-to-start/12219 "2023-12-11T19:16:28Z")
Background The klipper-mcu process fails to start on certain Linux distributions, even when the relevant documentation is carefully followed. This issue primarily affects Armbian Linux distributions or those based on Ar… --- ## [BRLtty / ModemManager - Services Interfering with Klipper](https://klipper.discourse.group/t/brltty-modemmanager-services-interfering-with-klipper/10611)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [September 21, 2023, 3:04pm UTC](https://klipper.discourse.group/t/brltty-modemmanager-services-interfering-with-klipper/10611 "2023-09-21T15:04:05Z")
Background Some Linux distributions, particularly their desktop variants, may install services that interfere with connected printer boards. This can result in Klipper losing the ability to connect to the board or comman… --- ## [No trigger on \[X / Y / Z\] after full movement](https://klipper.discourse.group/t/no-trigger-on-x-y-z-after-full-movement/13404)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [January 22, 2024, 4:48pm UTC](https://klipper.discourse.group/t/no-trigger-on-x-y-z-after-full-movement/13404 "2024-01-22T16:48:55Z")
Background A No trigger on \[X / Y / Z\] after full movement is thrown during homing moves. This error occurs when Klipper fails to detect an end-stop signal during homing, despite utilizing the available movement range. … --- ## [Testing Klipper Pull Requests](https://klipper.discourse.group/t/testing-klipper-pull-requests/21551)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [January 22, 2025, 12:02pm UTC](https://klipper.discourse.group/t/testing-klipper-pull-requests/21551 "2025-01-22T12:02:49Z")
Rational New features and changes to Klipper are typically managed via Pull Requests (PR) against the Klipper main repository on GitHub. If one wants to evaluate individual PRs and potentially provide feedback, there is… --- ## [Move exceeds maximum extrusion (AA mm^2 vs BB mm^2)](https://klipper.discourse.group/t/move-exceeds-maximum-extrusion-aa-mm-2-vs-bb-mm-2/6636)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:18am UTC](https://klipper.discourse.group/t/move-exceeds-maximum-extrusion-aa-mm-2-vs-bb-mm-2/6636 "2023-02-13T11:18:27Z")
Move exceeds maximum extrusion (AA mm^2 vs BB mm^2) Background Klipper has a safety mechanism that checks if a single move extrudes an unhealthy amount of filament or if the extrusion of multiple moves add up to such an … --- ## [Timer too close](https://klipper.discourse.group/t/timer-too-close/6634)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:17am UTC](https://klipper.discourse.group/t/timer-too-close/6634 "2023-02-13T11:17:28Z")
Timer too close Background A “Timer too close” error occurs when the MCU is asked to schedule an action at a time that is already in the past. This typically results from delayed communication between the host and the MC… --- ## [Got EOF when reading from device](https://klipper.discourse.group/t/got-eof-when-reading-from-device/6638)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:19am UTC](https://klipper.discourse.group/t/got-eof-when-reading-from-device/6638 "2023-02-13T11:19:37Z")
Got EOF when reading from device Background This is actually an error raised by Linux operating system (OS) of the host and only reported by Klipper. It indicated that the contact to an attached hardware (mostly the MCU … --- ## [Advanced Trouble-Shooting / Graphing Klipper](https://klipper.discourse.group/t/advanced-trouble-shooting-graphing-klipper/6613)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 12, 2023, 2:51pm UTC](https://klipper.discourse.group/t/advanced-trouble-shooting-graphing-klipper/6613 "2023-02-12T14:51:06Z")
Advanced Trouble-Shooting / Graphing Klipper The klippy.log is key for trouble-shooting and diagnosing errors, containing an abundance of information and also low-level details. In Klipper’s tool-box are additional tools … --- ## [Internal error in MCU 'mcu' stepcompress](https://klipper.discourse.group/t/internal-error-in-mcu-mcu-stepcompress/6644)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:22am UTC](https://klipper.discourse.group/t/internal-error-in-mcu-mcu-stepcompress/6644 "2023-02-13T11:22:22Z")
Internal error in MCU ‘mcu’ stepcompress Background An unforeseen issue in the stepcompress logic has happened. Reasons This is an error that should not happen under normal operating conditions Often this appears in th… --- ## [Working with Line Voltage (110 V / 230 V / \>50 V)](https://klipper.discourse.group/t/working-with-line-voltage-110-v-230-v-50-v/10805)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [October 3, 2023, 12:35pm UTC](https://klipper.discourse.group/t/working-with-line-voltage-110-v-230-v-50-v/10805 "2023-10-03T12:35:32Z")
Dangers of Line Voltage Line voltage poses serious hazards and can cause injury or death or damage to equipment. Voltages above 50 volts are typically considered dangerous (depending on the regulation). Always obey loca… --- ## [3D Printers with Preinstalled and Modified Klipper Versions](https://klipper.discourse.group/t/3d-printers-with-preinstalled-and-modified-klipper-versions/20467)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [December 5, 2024, 8:37am UTC](https://klipper.discourse.group/t/3d-printers-with-preinstalled-and-modified-klipper-versions/20467 "2024-12-05T08:37:20Z")
Rationale With the growing popularity of Klipper as a firmware option for high-speed, high-quality 3D printing, some Original Equipment Manufacturers (OEMs) have started shipping 3D printers with preinstalled, modified v… --- ## [Debian 11 (Bullseye) udev bug - No board or serial found](https://klipper.discourse.group/t/debian-11-bullseye-udev-bug-no-board-or-serial-found/10711)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [September 27, 2023, 6:09pm UTC](https://klipper.discourse.group/t/debian-11-bullseye-udev-bug-no-board-or-serial-found/10711 "2023-09-27T18:09:47Z")
Background In recent updates, Debian Bullseye (Debian 11) introduced a bug in udev that causes the command ls /dev/serial/by-id/\* to fail, because the bug prevents the creation of this device path. As of writing this,… --- ## [Creality Sonic Pad and Alternatives](https://klipper.discourse.group/t/creality-sonic-pad-and-alternatives/6324)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 1\ **Last updated:** [May 19, 2023, 9:40am UTC](https://klipper.discourse.group/t/creality-sonic-pad-and-alternatives/6324 "2023-05-19T09:40:12Z")
Creality Sonic Pad :exclamation: Update Since July 11, 2023, Creality seems to have released a firmware with a newer Klipper version. Again, they have not released the sources for this and the other components as requ… --- ## [Can not update MCU '\' config as it is shutdown](https://klipper.discourse.group/t/can-not-update-mcu-name-config-as-it-is-shutdown/9392)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [July 10, 2023, 11:33am UTC](https://klipper.discourse.group/t/can-not-update-mcu-name-config-as-it-is-shutdown/9392 "2023-07-10T11:33:39Z")
Can not update MCU '\' config as it is shutdown Background The Klipper host process on the SBC is starting or restarting, but cannot properly connect to the respective MCU because it is in a shutdown / error state. … --- ## [Troubleshooting Spontaneous SBC Reboots and Crashes in Klipper](https://klipper.discourse.group/t/troubleshooting-spontaneous-sbc-reboots-and-crashes-in-klipper/24476)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [August 3, 2025, 5:17pm UTC](https://klipper.discourse.group/t/troubleshooting-spontaneous-sbc-reboots-and-crashes-in-klipper/24476 "2025-08-03T17:17:19Z")
Troubleshooting Spontaneous SBC Reboots and Crashes in Klipper This guide provides a structured approach to diagnosing and resolving system instability or sudden crashes with the Single Board Computer (SBC) used for your… --- ## [MCU 'mcu' shutdown: Command request / Shutdown due to webhooks request](https://klipper.discourse.group/t/mcu-mcu-shutdown-command-request-shutdown-due-to-webhooks-request/6641)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:20am UTC](https://klipper.discourse.group/t/mcu-mcu-shutdown-command-request-shutdown-due-to-webhooks-request/6641 "2023-02-13T11:20:54Z")
MCU ‘mcu’ shutdown: Command request / Shutdown due to webhooks request Background This is not an error but an information that the Klipper Host actively and intentionally received a request to shutdown Reasons A M112 (… --- ## [Issues flashing the printer board](https://klipper.discourse.group/t/issues-flashing-the-printer-board/14015)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 10, 2024, 6:35pm UTC](https://klipper.discourse.group/t/issues-flashing-the-printer-board/14015 "2024-02-10T18:35:15Z")
Background Some printer boards are seemingly unwilling to accept flashing the Klipper firmware. Typically, this results in: No board serial output with the command ls /dev/serial/by-id/\* Mcu: Serial connection closed /… --- ## [Interpreting the Input Shaper Graphs](https://klipper.discourse.group/t/interpreting-the-input-shaper-graphs/9879)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [August 11, 2023, 6:56am UTC](https://klipper.discourse.group/t/interpreting-the-input-shaper-graphs/9879 "2023-08-11T06:56:21Z")
Interpreting the Input Shaper Graphs Content Theory - Resonances Theory - Power Spectral Density (PSD) Understanding the Graph How the shaper is recommended General Guidelines Identifying Mechanical Problems If you ar… --- ## [SpreadCycle and StealthChop (an advanced guide)](https://klipper.discourse.group/t/spreadcycle-and-stealthchop-an-advanced-guide/23938)
**Author:** [@koconnor](https://klipper.discourse.group/u/koconnor)\ **Replies:** 0\ **Last updated:** [June 19, 2025, 4:13pm UTC](https://klipper.discourse.group/t/spreadcycle-and-stealthchop-an-advanced-guide/23938 "2025-06-19T16:13:17Z")
This article is about the implementation details of Trinamic stepper motor drivers. The goal is to give an intuition for how these drivers operate. This may be useful for those interested in tuning the low-level parame… --- ## [Unable to write tmc spi 'stepper' register GLOBALSCALER](https://klipper.discourse.group/t/unable-to-write-tmc-spi-stepper-register-globalscaler/24193)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [July 10, 2025, 5:25pm UTC](https://klipper.discourse.group/t/unable-to-write-tmc-spi-stepper-register-globalscaler/24193 "2025-07-10T17:25:27Z")
Unable to write tmc spi ‘stepper’ register GLOBALSCALER Background The error “Unable to write tmc spi ‘stepper\_…’ register…” indicates that your printer’s microcontroller unit (MCU) has failed to communicate with a speci… --- ## [Move out of range: X Y Z \[E\]](https://klipper.discourse.group/t/move-out-of-range-x-y-z-e/6637)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:18am UTC](https://klipper.discourse.group/t/move-out-of-range-x-y-z-e/6637 "2023-02-13T11:18:51Z")
Move out of range: X Y Z \[E\] Background A movement beyond the physical limits was attempted. Also refer to Understanding X and Y Axes Limits and Homing Reasons A direct movement command (G1 et al.) tried to move to a l… --- ## [Will a Klipper Printer print much faster?](https://klipper.discourse.group/t/will-a-klipper-printer-print-much-faster/6322)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [January 31, 2023, 6:45am UTC](https://klipper.discourse.group/t/will-a-klipper-printer-print-much-faster/6322 "2023-01-31T06:45:46Z")
Will a Klipper Printer print much faster? There is a widespread word that installing Klipper will make the 3D printer much faster than with any other other firmware. This is essentially false or only true under certain… --- ## [Klippy.log - Statistics and Interpretation](https://klipper.discourse.group/t/klippy-log-statistics-and-interpretation/23563)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [May 22, 2025, 7:46pm UTC](https://klipper.discourse.group/t/klippy-log-statistics-and-interpretation/23563 "2025-05-22T19:46:07Z")
klippy.log - Statistics and Interpretation Table of Contents Introduction Statistics Explained Classification 1. Host System Statistics 2. Print Progress Statistics 3. MCU Specific Statistics MCU Load & Task Timing C… --- ## [Understanding X and Y Axes Limits and Homing](https://klipper.discourse.group/t/understanding-x-and-y-axes-limits-and-homing/10779)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [October 2, 2023, 5:57am UTC](https://klipper.discourse.group/t/understanding-x-and-y-axes-limits-and-homing/10779 "2023-10-02T05:57:20Z")
The X and Y Axis Klipper needs to know from its printer.cfg settings how far the X and Y axes can safely move without hitting the printer’s frame. It also needs to know where the origin (X=0 / Y=0) is. This origin is th… --- ## [Mcu: Serial connection closed / Timeout on connect / Wait for identify\_response](https://klipper.discourse.group/t/mcu-serial-connection-closed-timeout-on-connect-wait-for-identify-response/6645)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:22am UTC](https://klipper.discourse.group/t/mcu-serial-connection-closed-timeout-on-connect-wait-for-identify-response/6645 "2023-02-13T11:22:46Z")
mcu: Serial connection closed / Timeout on connect / Wait for identify\_response Background The printer-board / MCU did not respond to the connection attempt of the Klipper Host until finally the serial connection timed o… --- ## [Rescheduled timer in the past](https://klipper.discourse.group/t/rescheduled-timer-in-the-past/6635)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [February 13, 2023, 11:17am UTC](https://klipper.discourse.group/t/rescheduled-timer-in-the-past/6635 "2023-02-13T11:17:55Z")
Background Whereas Time too close rather indicates an overloaded / jammed host, this error points to an overloaded MCU Reasons Too high step rate Potential solutions Check for approaching the limit: Check the Benchm… --- ## [How-To Ask for Help](https://klipper.discourse.group/t/how-to-ask-for-help/6327)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [January 31, 2023, 6:56am UTC](https://klipper.discourse.group/t/how-to-ask-for-help/6327 "2023-01-31T06:56:25Z")
How-To Ask for Help General All contributors here help out in their spare time and because they want to give something back to the Klipper project. Be respectful and patient. If someone knows the answer to your question,… --- ## [TMC 'stepper' reports GSTAT: 00000001 reset=1(Reset)](https://klipper.discourse.group/t/tmc-stepper-reports-gstat-00000001-reset-1-reset/19801)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [November 1, 2024, 5:07pm UTC](https://klipper.discourse.group/t/tmc-stepper-reports-gstat-00000001-reset-1-reset/19801 "2024-11-01T17:07:51Z")
TMC ‘stepper’ reports GSTAT: 00000001 reset=1(Reset) Background During the startup phase of the printer, the relevant TMC driver registers are programmed by Klipper. This includes, but is not limited to, run\_current, mic… --- ## [Missed scheduling of next digital out event](https://klipper.discourse.group/t/missed-scheduling-of-next-digital-out-event/14775)
**Author:** [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Replies:** 0\ **Last updated:** [March 9, 2024, 8:01am UTC](https://klipper.discourse.group/t/missed-scheduling-of-next-digital-out-event/14775 "2024-03-09T08:01:14Z")
Missed scheduling of next digital out event Background When the host activates a heater on the MCU (heater\_pin is set high), the MCU will request a confirmation every 5 seconds to secure that the heater is intended to be… [Next page](https://klipper.discourse.group/c/knowledge-base/16.md?page=1)