Spindle delay is not delaying!

Community Support ❓ Something's Up
1

I have the Longmill MK 1 with the SLB and spindle upgrades.

I have set the delay to 11 seconds both in the firmware $392 and in gsender setting under spindle delay, but there is no delay what so ever.

Thanks in advance for any help to fix this problem.

2

Without more info, I’ll take a stab in dark:

  • if you’re using gSender, check that you’ve selected ‘grblHAL’ as the firmware when you connect to your machine, not ‘grbl’.

Or an AI thought or two to help you get started on the problem:

Verify VFD “At Speed” Tolerance Settings

With the SLB and the Sienci H-100 VFD spindle upgrade, the board handles delays dynamically by checking if the spindle has reached its target RPM before starting the cut. If the threshold parameters are misconfigured, it may falsely assume the spindle is ready instantly. [1, 2]

  1. Go to the Firmware tab in gSender.
  2. Verify that $340 (Spindle at speed tolerance) is set to its default value of 5.
  3. Ensure $395 (Current Spindle) is correctly set to 6 (H-100 VFD Spindle). If it resets to 0 or another value, the board won’t listen to the VFD’s state. [1, 2, 3]

3. Check for a gSender Software Bug

There is a known bug in certain versions of gSender (notably version 1.6.0) where the built-in spindle on-delay fails to execute altogether, regardless of what is typed into the configuration.

  • Fix: Check your gSender version. If you are on an affected build, updating to the latest stable release or rolling back to a stable version (like 1.5.7) usually restores the delay.

4. The Fail-Safe Workaround: Post-Processor Dwell

If you need to cut projects immediately and can’t get the firmware delay to trigger, you can force the machine to pause by editing your CAM post-processor. [1, 2]

  • In your CAM software (like VCarve, Fusion 360, or Carbide Create), edit your Post Processor to insert a G4 (Dwell) command right after the M3 (Spindle On) command.

  • For an 11-second delay, the code injected into the g-code should look like:

    gcode

    M3 S18000 ; Spindle turns on
G4 P11    ; Dwell/pause for 11 seconds before moving

    Use code with caution.