diff --git a/resources/definitions/anycubic_i3_mega_s.def.json b/resources/definitions/anycubic_i3_mega_s.def.json
index 4fb9aa2b4e..b623b984a2 100644
--- a/resources/definitions/anycubic_i3_mega_s.def.json
+++ b/resources/definitions/anycubic_i3_mega_s.def.json
@@ -33,11 +33,15 @@
         "machine_end_gcode": { "default_value": "M104 S0                                    ; Extruder off \nM140 S0                                    ; Heatbed off \nM107                                       ; Fan off \nG91                                        ; relative positioning \nG1 E-5 F300                                ; retract a little \nG1 Z+10 E-5 ; X-20 Y-20 F{travel_xy_speed} ; lift print head \nG28 X0 Y0                                  ; homing \nG1 Y180 F2000                              ; reset feedrate \nM84                                        ; disable stepper motors \nG90                                        ; absolute positioning \nM300 S440 P200                             ; Make Print Completed Tones \nM300 S660 P250                             ; beep \nM300 S880 P300                             ; beep" },
 
         "machine_max_acceleration_x": { "value": 3000 },
-        "machine_max_acceleration_y": { "value": 3000 },
-        "machine_max_acceleration_z": { "value": 3000 },
-        "machine_max_acceleration_e": { "value": 3000 },
+        "machine_max_acceleration_y": { "value": 2000 },
+        "machine_max_acceleration_z": { "value": 60 },
+        "machine_max_acceleration_e": { "value": 10000 },
         "machine_acceleration": { "value": 3000 },
 
+        "machine_max_feedrate_x": { "default_value": 500 },
+        "machine_max_feedrate_y": { "default_value": 500 },
+        "machine_max_feedrate_z": { "default_value": 6 },
+
         "machine_max_jerk_xy": { "value": 10 },
         "machine_max_jerk_z": { "value": 0.4 },
         "machine_max_jerk_e": { "value": 5 },
diff --git a/resources/definitions/anycubic_i3_mega_x.def.json b/resources/definitions/anycubic_i3_mega_x.def.json
index 07341b15c2..feef2547ab 100644
--- a/resources/definitions/anycubic_i3_mega_x.def.json
+++ b/resources/definitions/anycubic_i3_mega_x.def.json
@@ -14,13 +14,23 @@
         "machine_height": { "default_value": 305 },
         "machine_depth": { "default_value": 300 },
 
+        "machine_max_acceleration_x": { "value": 400 },
+        "machine_max_acceleration_y": { "value": 400 },
+        "machine_max_acceleration_z": { "value": 60 },
+        "machine_max_acceleration_e": { "value": 10000 },
+        "machine_acceleration": { "value": 3000 },
+
+        "machine_max_feedrate_x": { "default_value": 120 },
+        "machine_max_feedrate_y": { "default_value": 120 },
+        "machine_max_feedrate_z": { "default_value": 12 },
+
         "speed_travel": { "value": 100.0,  "maximum_value": 120.0 },
 
         "acceleration_print": { "value": 400 },
         "acceleration_travel": { "value": 400 }
         
-        "retraction_speed": { "value": 30, "maximum_value_warning": 80 },
-        "retraction_retract_speed": { "maximum_value_warning": 80 },
-        "retraction_prime_speed": { "maximum_value_warning": 80 }
+        "retraction_speed": { "value": 30, "maximum_value_warning": 60 },
+        "retraction_retract_speed": { "maximum_value_warning": 60 },
+        "retraction_prime_speed": { "maximum_value_warning": 60 }
     }
 }
\ No newline at end of file