# Transition to shutdown state: MCU 'CB1' shutdown: Stepper too far in past **URL:** \ **Category:** General Discussion\ **Created:** [June 5, 2024, 11:07am UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850 "2024-06-05T11:07:04Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![TheDoshs](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TheDoshs](https://klipper.discourse.group/u/TheDoshs)\ **Post date:** [June 5, 2024, 11:07am UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/1 "2024-06-05T11:07:04Z")
### Basic Information: Printer Model: [Custom](https://klipper.discourse.group/t/scara-kinematic/11663) MCU / Printerboard: Bigtreetech Manta M8P Host / SBC: BIGTREETECH CB1 Good afternoon everyone! Sometimes it happens that during printing an error appears like > Transition to shutdown state: MCU ‘CB1’ shutdown: Stepper too far in past Any ideas why this might be happening? I am attaching the log file and gcode : [dino.gcode](https://klipper.discourse.group/uploads/short-url/g4nJnNtlpT3Eq7X4yIBs7wsYUmj.gcode) (5.6 MB) [klippy.log](https://klipper.discourse.group/uploads/short-url/4dmMgUKemlnVxW6D4ANv4CbePyM.log) (7.0 MB) ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [June 5, 2024, 2:09pm UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/2 "2024-06-05T14:09:44Z")
Likely connected to your `step_pulse_duration = 0.000005` setting. This artificially limits the max step rate and with this the max velocity that motor can achieve. If you nevertheless exceed this limit, then this error will be raised. ---
**Author:** ![TheDoshs](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TheDoshs](https://klipper.discourse.group/u/TheDoshs)\ **Post date:** [June 6, 2024, 6:44am UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/3 "2024-06-06T06:44:01Z")
According to the idea, we are already at the limit because of the driver or am I deeply mistaken? ![image](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/8/86b8c630f13c8da03cbc360546d3a5ba0ea94e34.png) ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [June 6, 2024, 6:59am UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/4 "2024-06-06T06:59:58Z")
I’m by no means an expert on stepper drivers. All I can tell you that my (hopefully correct) interpretation of the error is: You are generating more steps than the stepper driver can process / consume due to its timing constraints. As a consequence, the motor starts lagging behind its target and at some point Klipper is telling you that the “Stepper is too far in the past” ---
**Author:** ![TheDoshs](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TheDoshs](https://klipper.discourse.group/u/TheDoshs)\ **Post date:** [June 10, 2024, 7:10am UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/5 "2024-06-10T07:10:18Z")
Thank you! After increasing step\_pulse\_duration and decreasing microsteps this problem no longer appeared. ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [July 10, 2024, 5:10pm UTC](https://klipper.discourse.group/t/transition-to-shutdown-state-mcu-cb1-shutdown-stepper-too-far-in-past/16850/6 "2024-07-10T17:10:42Z")
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