Hi,
I’ve noticed that when using helical operations, the actual cut speed is different from what I set in Kiri:Moto — sometimes faster, sometimes slower.
After checking the G‑code, I found the cause: Kiri sets a feedrate on a G0 move, but not on the G1 moves, so the cutting feedrate becomes whatever the last G1 feedrate was in a previous operation.
Example from a helical op:
; starting helical op
M3 S12000
G4 P5
G0 X18.1735 Y0.0 F400
G1 Z-0.0100
G1 X16.5860
G1 X16.5759 Y0.5772 Z-0.0122
G1 X16.5458 Y1.1537 Z-0.0144
G1 X16.4956 Y1.7289 Z-0.0166
G1 X16.4254 Y2.3019 Z-0.0189
There is no F‑value on any of the G1 moves, so the machine uses the previous modal G1 feedrate from an earlier operation.
Compare that with an outline op:
; starting outline op
G0 F6000 ; default rapid move speed
M6 T14 ; change tool
G0 X0.0 Y0.0 F6000
G0 Z1.9900
G0 X2.5174 Y-17.9117 F800
M3 S12000
G4 P5
G1 Z-0.3946 F200
G1 X3.1408 Y-17.8130 F640
G1 X3.7608 Y-17.6924
Here the G1 feedrates are explicitly set, so the speeds are correct.
Conclusion:
Helical ops inherit the last modal G1 feedrate unless Kiri emits an explicit F on the first G1 move. If the previous op had a slow plunge feed, the helical op will run at that slow feedrate.
It would be helpful if Kiri:Moto emitted a feedrate on the first G1 of a helical operation, or if there was an option to “emit all feedrates” for consistency.
Hi,
I’ve noticed that when using helical operations, the actual cut speed is different from what I set in Kiri:Moto — sometimes faster, sometimes slower.
After checking the G‑code, I found the cause: Kiri sets a feedrate on a G0 move, but not on the G1 moves, so the cutting feedrate becomes whatever the last G1 feedrate was in a previous operation.
Example from a helical op:
; starting helical op
M3 S12000
G4 P5
G0 X18.1735 Y0.0 F400
G1 Z-0.0100
G1 X16.5860
G1 X16.5759 Y0.5772 Z-0.0122
G1 X16.5458 Y1.1537 Z-0.0144
G1 X16.4956 Y1.7289 Z-0.0166
G1 X16.4254 Y2.3019 Z-0.0189
There is no F‑value on any of the G1 moves, so the machine uses the previous modal G1 feedrate from an earlier operation.
Compare that with an outline op:
; starting outline op
G0 F6000 ; default rapid move speed
M6 T14 ; change tool
G0 X0.0 Y0.0 F6000
G0 Z1.9900
G0 X2.5174 Y-17.9117 F800
M3 S12000
G4 P5
G1 Z-0.3946 F200
G1 X3.1408 Y-17.8130 F640
G1 X3.7608 Y-17.6924
Here the G1 feedrates are explicitly set, so the speeds are correct.
Conclusion:
Helical ops inherit the last modal G1 feedrate unless Kiri emits an explicit F on the first G1 move. If the previous op had a slow plunge feed, the helical op will run at that slow feedrate.
It would be helpful if Kiri:Moto emitted a feedrate on the first G1 of a helical operation, or if there was an option to “emit all feedrates” for consistency.