I know web streaming on the Pi W under OctoPi is a no-no. So I disabled the webcamd via crontab at boot and verified that it was indeed disabled via SSH into OctoPi:
service webcamd status
and it is showing that its not started:
● webcamd.service - LSB: webcam daemon Loaded: loaded (/etc/init.d/webcamd; generated; vendor preset: enabled) Active: inactive (dead) since Tue 2018-08-14 21:54:19 CST; 34min ago Docs: man:systemd-sysv-generator(8) Process: 466 ExecStop=/etc/init.d/webcamd stop (code=exited, status=0/SUCCESS) Process: 407 ExecStart=/etc/init.d/webcamd start (code=exited, status=0/SUCCES Aug 14 21:54:19 Kossel systemd: Starting LSB: webcam daemon... Aug 14 21:54:19 Kossel webcamd: Starting Webcam Daemon: webcamd. Aug 14 21:54:19 Kossel systemd: Started LSB: webcam daemon. Aug 14 21:54:19 Kossel systemd: Stopping LSB: webcam daemon... Aug 14 21:54:19 Kossel webcamd: Stopping Webcam Daemon: webcamd. Aug 14 21:54:19 Kossel systemd: Stopped LSB: webcam daemon.
Yet, prints still stutter under the Pi W. And I even closed the OctoPi Web page, and it still stutters.
I popped the SD card out of the Pi W and put it in the Pi 3B+ and stuttering disappeared, of course (exact same gCode file)
This is on an AnyCubic Kossel Delta 3D Printer running Marlin 1.1.9
Latest version of OctoPrint v1.3.9
OctoPi version 0.15.1
I'm printing at 40mm/s
USB Baud Rate is 250000
Am I missing something or is the Pi W just not even fast enough to send G-code commands to the printer - period??