I’m experiencing a weird floating circle on layer 54 of my preview. It even goes beyond plate boundary. The circle is not present in Fusion 360 and I can’t figure out what is going on. It only seems to happen with this file. Any ideas as to what may be occurring here?
Thanks so much!
Normally that is what a skirt looks like. Your settings are scrolled so that I cannot see all the skirt settings.
Of course, the skirt should not be offset like what I see on your image.
Does the circle move when you change the view angle?
I also notice that the circle is in the color for the outer wall.
Can you go back to prepare, select the object and upload this message box?
I just noticed another thing - you are using custom gcode. When preview draws the model it is actually using the gcode that is going to be sent to the printer to do it. Therefore, if you have anything in your machine start gcode preview will show it.
Can you post your machine start gcode?
If you are willing to share the model it would also help.
The answer is in the start code, or the model, and if you don’t have the circle showing in prepare then it is probably in the start code.
Hello Julie, I really appreciate your help here. 
I don’t believe it’s the custom minimalist Gcode because I use it on other models all the time with no issues.
I also have skirt off but what’s weird is that this circle is occurring on layer 54, which a skirt should not. Yes, the circle moves with the model when I change the view angle. It is not present in prepare, only in preview.
When I go to prepare and select the object it shows this message box:
I’m happy to share the model but how can I do that? Upload doesn’t allow that file type
Here’s the custom start GCode as well:
Blockquote
;===== date: 202200815 =====================
;===== reset machine status =================
G91
M17 Z0.3 ; lower the z-motor current
G0 Z7 F300 ; lower the hotbed , to prevent the nozzle is below the hotbed
G90
M17 X1.2 Y1.2 Z0.75 ; reset motor current to default
M960 S5 P1 ; turn on logo lamp
G90
M220 S100 ;Reset Feedrate
M221 S100 ;Reset Flowrate
M73.2 R1.0 ;Reset left time magnitude
M1002 set_gcode_claim_speed_level : 5
M221 X0 Y0 Z0 ; turn off soft endstop to prevent protential logic problem
;===== heatbed preheat ====================
M1002 gcode_claim_action : 2
{if bbl_bed_temperature_gcode}
M1002 set_heatbed_surface_temp:[bed_temperature_initial_layer_vector] ;config bed temps
M140 A S[bed_temperature_initial_layer_single] ;set bed temp
M190 A S[bed_temperature_initial_layer_single] ;wait for bed temp
{else}
M140 S[bed_temperature_initial_layer_single] ;set bed temp
M190 S[bed_temperature_initial_layer_single] ;wait for bed temp
{endif}
=============turn on fans to prevent PLA jamming=================
{if filament_type[initial_tool]==“PLA”}
{if (bed_temperature[current_extruder] >45)||(bed_temperature_initial_layer[current_extruder] >45)}
M106 P3 S100
{elsif (bed_temperature[current_extruder] >50)||(bed_temperature_initial_layer[current_extruder] >50)}
M106 P3 S100
{endif};Prevent PLA from jamming
{endif}
M106 P2 S100 ; turn on big fan ,to cool down toolhead
;===== prepare print temperature and material ==========
M104 S[nozzle_temperature_initial_layer] ;set extruder temp
G91
G0 Z2 F1200
G90
G28 X
M975 S1 ; turn on
G1 X60 F12000
G1 Y245
G1 Y265 F3000
M620 M
M620 S[initial_tool]A ; switch material if AMS exist
M109 S[nozzle_temperature_initial_layer]
G1 X120 F12000
G1 X20 Y50 F12000
G1 Y-3
T[initial_tool]
G1 X54 F12000
G1 Y265
M400
M621 S[initial_tool]A
M412 S1 ; ===turn on filament runout detection===
M109 S250 ;set nozzle to common flush temp
M106 P1 S0
G92 E0
G1 E50 F200
M400
M104 S[nozzle_temperature_initial_layer]
G92 E0
G1 E20 F200
M400
M106 P1 S255
G92 E0
G1 E5 F300
M109 S{nozzle_temperature_initial_layer[initial_extruder]-20} ; drop nozzle temp, make filament shink a bit
G92 E0
G1 E-0.5 F300
G1 X70 F9000
G1 X76 F15000
G1 X65 F15000
G1 X76 F15000
G1 X65 F15000; shake to put down garbage
G1 X80 F6000
G1 X95 F15000
G1 X80 F15000
G1 X165 F15000; wipe and shake
M400
M106 P1 S0
;===== prepare print temperature and material end =====
;===== wipe nozzle ===============================
M1002 gcode_claim_action : 14
M975 S1
M106 S255
G1 X65 Y230 F18000
G1 Y264 F6000
M109 S{nozzle_temperature_initial_layer[initial_extruder]-20}
G1 X100 F18000 ; first wipe mouth
G0 X135 Y253 F20000 ; move to exposed steel surface edge
G28 Z P0 T300; home z with low precision,permit 300deg temperature
G29.2 S0 ; turn off ABL
G0 Z2 F20000
G1 X60 Y265
G92 E0
G1 E-0.5 F300 ; retrack more
G1 X100 F5000; second wipe mouth
G1 X70 F15000
G1 X100 F5000
G1 X70 F15000
G1 X100 F5000
G1 X70 F15000
G1 X100 F5000
G1 X70 F15000
G1 X90 F5000
M104 S160 ; set temp down to heatbed acceptable
M106 S255 ; turn on fan (G28 has turn off fan)
M221 R; pop softend status
G1 Z10 F1200
M400
G1 Z10
G1 F30000
G1 X230 Y15
G29.2 S1 ; turn on ABL
;G28 ; home again after hard wipe mouth
M106 S0 ; turn off fan , too noisy
;===== wipe nozzle end ================================
;===== bed leveling ==================================
M1002 judge_flag g29_before_print_flag
M622 J1
M1002 gcode_claim_action : 1
G29 A X{first_layer_print_min[0]} Y{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
M400
M500 ; save cali data
M623
;===== bed leveling end ================================
;===== home after wipe mouth============================
M1002 judge_flag g29_before_print_flag
M622 J0
M1002 gcode_claim_action : 13
G28
M623
;===== home after wipe mouth end =======================
M975 S1 ; turn on vibration supression
=============turn on fans to prevent PLA jamming=================
{if filament_type[initial_tool]==“PLA”}
{if (bed_temperature[current_extruder] >45)||(bed_temperature_initial_layer[current_extruder] >45)}
M106 P3 S100
{elsif (bed_temperature[current_extruder] >50)||(bed_temperature_initial_layer[current_extruder] >50)}
M106 P3 S100
{endif};Prevent PLA from jamming
{endif}
M106 P2 S100 ; turn on big fan ,to cool down toolhead
M104 S{nozzle_temperature_initial_layer[initial_extruder]} ; set extrude temp earlier, to reduce wait time
;===== noozle load line ===============================
M975 S1
G90
M83
T1000
G1 X18.0 Y5.0 Z0.3 F18000;Move to start position
M109 S{nozzle_temperature[initial_extruder]}
G0 E3 F300
G0 X240 E15 F{outer_wall_volumetric_speed/(0.3*0.5) * 60}
G0 Y5.5
G0 X18 E15
M400
;========turn off light and wait extrude temperature =============
M1002 gcode_claim_action : 0
M106 S0 ; turn off fan
M106 P2 S0 ; turn off big fan
M106 P3 S0 ; turn off chamber fan
M975 S1 ; turn on mech mode supression
Basic debug process - remove that custom code and see if the problem goes away… definitively determine if it’s having an effect.
Hi James.
The fact that it is layer 56 does make a huge difference. I couldn’t tell that from the image.
@RocketSled makes a good point. It is easy to just change printer profiles to the standard one and slice. The preview will give you that answer. Preview is actually simulating the gcode to produce the image.
From the size information that the slicer is showing, it looks like it is sizing the model correctly.
Are there any errors about the model when you import it? For example sometimes the imported model has a defect so it is not a closed surface.
It could be a slicer bug.
My steps would be to try different printer and process presets and see if they all do the same thing.
If they do, then I would try it with Prusa Slicer to see if it is a BS bug.
Good luck.