In the e3d config.g, I see: Code: [B];[/B]Stall Detection [B]M915[/B] C S5 F0 H200 R4700 [B];[/B] Coupler [B];[/B]Stall Detection [B]M915[/B] X Y S5 F0 H400 R4700 [B];[/B] X / Y Axes However, from the latest RRF gcode reference I can find (https://duet3d.dozuki.com/Wiki/Gcode#Section_M915_Configure_motor_stall_detection) M915: Configure motor stall detection ... - Rn Action to take on detecting a stall from any of these drivers: 0 = no action (default), 1 = just log it, 2 = pause print, 3 = pause print, execute /sys/rehome.g, and resume print Legal values for R appear to be 0/1/2/3. 4700 is just a bit out of range. I'm using RRF2 at this point, but this documentation covers RRF3 as well and it seems to be the same for both. [Partly answering my own question, I found this from dc42: "The R parameter is not relevant when using stall detection endstops.". That changes my question to "Why is R4700 even in there, then??" Magic numbers in my config bug me, so trying to understand the background.