Here’s my separate thread on how to set TCON/TCOFF correctly.
Actually, what I see is that you don’t set TCON/TCOFF based on speed or material. The machine’s timing is what it is and that is the only thing TCON/TCOFF should be set for. Recalibrating for other factors like increasing TCON to reduce starting overburn might effectively reduce the overburn and improve that one feature, but then the machine’s timing is wrong overall and you could spend forever tinkering by tweaking the timing for each material, speed, power, etc.
I do see I was wrong in assuming we’re taking lone vectors with a stop at the start and end points. Clearly that’s not the case- the start point is wide or even a pit drilled in the material, the fat “matchhead” end. But the other is a tail that narrows out. So we’re not “overscanning” by using a runway to reach the commanded speed before turning on the laser as it crosses the specified start point, but we do seem to coast past the stop point and just turn off the fire command as it passes the stop point, there’s no braking there. That more or less meets my definition of overscanning for the stop point (on unchained vectors only)
That’s specifically in the case of a lone, unchained vector. If it’s chained, like a 90 deg corner with the next vector from the same point, the BJJCZ brakes to a stop at the corner, waits PolygonTC for the mirror to settle, then starts accelerating in the other direction. It does prevent the mirror from visibly wobbling, but adds all this overburn.
This does seem to be all on the BJJCZ’s side, but it would have made more sense have separate timing params for PolygonTC for the galvo position and laser fire command. It should wait for the mirror to settle down before taking off in a new direction, but it doesn’t need to keep the beam on while doing that.