Slow move XY when add rotary axis

Hi
I build cnc machine with rotary tool mount on the head.
I have problem with move speeds. This problem is similary to:
forum.linuxcnc.org/38-general-linuxcnc-q...-rotary-axis?start=0
but with some differences.

I have gcode when i use F10000 for speed definition. When i delete from this gcode all B commands (i use B as rotary axis). Move XY is very fast. Max speed is about 6000mm/min - picture no 1 - section "1-2". When I used gcode with B code the same speed go down to about 1200 - 1300mm/min - picture no 3 - section "1-2". In picture 3, section "2-3" -"G0 B0" and section "3-4" - "G0 X27.0300 Y135.5200 B180" show that axis B is able to move much faster. This is take me to conclusion that B axis is not a limitation.
Nothing change when i use gcode with G93 (i use pyton script to convert my gcode)

Could someone can help and explain me why I have much slower move when have B axis, and how can i increase this speed.

Tomek

In attachements i attach pictures with plot vel-cmd for X,Y and B axis in different situation.

Pic 1 - Gcode without rotary axis "testL-woB.ngc", Only G0,G1 move and G64.
Section 1-2 is lines 13-45
Section 2-3 is absent
Section 3-4 is line 48

Pic 2 - the same as pic 1 but all arc as G2, G3 not G1

Pic 3 - Gcode with rotary axis "testL.ngc", Only G0,G1 move and G64
Section 1-2 is lines 13-45
Section 2-3 is line 47
Section 3-4 is line 48

Pic 4 - the same as above but with G2, G3

Pic 5 - Gcode "testL.ngc" and filter in python to convert to G93 move

you need the G93 advantige
see here
www.ganotechnologies.com/cnc/rapidrotary/

Thanks bbsr_5a for quick answer but its not a solution

As I said i tired this solution. In picture 5, you have the speed of this gcode shown . I attach ngc file on witch I tested G93 solution
but It doesn't work. Max speed is about 1200-1300mm/min witch is the same as G94 solution

You do know that anytime a rotary axis is called out then the feed reverts to degrees/min? I use this calculation to figure it out based on the diameter the tool is cutting. Keep in mind this is for inch units. (360*(1/(3.14159*dia))*inches per min)=degrees per minute feed. The "inches per minute" in the calculation is the desired feed rate along the circumference. You can put this equation in a macro or Excell sreadsheet to calculate your feeds. Hope this helps.