Things seem to work fine at a speed of 800mm/s, but as I am not under time pressure I usually set the cutter to 100mm/s.
I cut vinyl at 26g, but what works for you will depend on what it is you are cutting. I control the speed and pressure from the control pad on the cutter itself. I had loads of problems getting this to work - I used to get an error message about 'permission denied' but after much internet searching got over this using the following command in Terminal 'sudo chmod a+rw /dev/ttyUSB0'. Under connection settings I have put serial baud rate to 2400 and serial flow control to none - I can't remember why now, but these seem to work for me. I have generally left the settings at the defaults. Have been using a Liyu SC631 with Inkscape to cut vinyl for a few years, under the Ubuntu operating system (currently 18.04).
