GregValiant

Load the model and set up your slice. Use the "File | Save Project" command and then post the saved 3mf file here. Somebody will take a look.

There is no Max value. The reason for that was technical and so I immediately forgot all the details. You can set the Minimum in the Wall Settings / Minimum Wall Line Width. Cura seems to respect the Minimum. There may be side effects to that (like maybe with Print Thin Walls).

@chris413 The image below is that first project file. You can see it's sitting on the bed. I get the same thing with the little ring you posted. We're beating this to death and not making any progress. Try installing a Creality Ender 3 and change the bed size to 250 x 250 x 250. Slice with the Ender active. If the problem is till present then that would eliminate the LotMaxx definition file and platform as the culprit.

@chris413 LotMaxx is one of the companies that has it's own fork of Cura. Are you using "UltiMaker" Cura, or "LotMaxx" Cura? I've installed a LotMaxx Shark but I can't duplicate the problem in UltiMaker Cura 5.2.1. The "Help | About..." command should tell you the Cura version you are using. Load a model and use the "File | Save Project" command and post the 3mf file here.

I don't know if replacing the mainboard will fix it. What information I was able to glean from the internet was spotty and imprecise. What appeared to be happening with certain Creality printers was that the mainboard does not communicate properly with the newer style TFT displays. When a command sends a message to the display (like M0 sends "click to resume") then the command is simply ignored. So is the problem in the display, the mainboard, or in the firmware? I don't know. I have a 4.2.7 mainboard sitting here that I've never installed. My 1.1.5 mainboard works well enough and supports the pause commands so I've been unwilling to experiment. If the older mainboard dies (been known to happen) then I'll stick the new one in. It may well work because my 3 year old Ender 3 Pro has the older regular LCD display which may (or may not) communicate properly with the 4.2.7 board without a firmware change. If those fixes I've described don't work for you then have you tried using G4 to pause? It's clumsy because it's a timed "pause" and can neither be shortened nor extended once the printer has read the command. G4 S300 should stop the print for 5 minutes at which time the printer will resume by itself. So the problem is that you would need to be watching for the printer to stop, act fairly quickly (depending on the "S" parameter which is in seconds) and then wait for the print to resume. The attached gcode file has the following script. Print it. If the nozzle stops for 30 seconds before the second G28 then G4 works on your printer. G28 ;auto-home all G0 F600 Z5 ;move Z up G0 F6000 X100 Y100 ;move X and Y G4 S30 ;pause for "S" seconds G28 X Y ;home X and Y only G4 test.gcode

This comes up a lot. We should have a sticky note here. The "platform" is just a cartoon and doesn't affect anything. You can adjust the location later. You need to match the midpoint of the virtual build plate in Cura to the real build plate on your printer. The printer will put the 0,0,0 origin of a gcode file at the printer's Home Offset 0,0,0 and so those points need to match up. Carefully measure your printer's actual "X Bed Width" and it's actual "Y Bed Depth". Subtract 5mm from each number and insert those new numbers into Cura in the Machine Settings as "X (width)" and "Y (depth)". Auto-Home the printer and move the Z up a couple of mm's. Use the LCD controls and send the nozzle to a point 2.5mm from the left edge of the build surface and 2.5mm from the front edge of the build surface. Move the Z back down to "0". On the LCD there should be a command for "Set Home Offset". Select it and then find "Save Settings" and select it. If any of that doesn't work, make sense, or the commands don't exist in the printer, then some trickery will need to be done.

By non-compatible I meant "won't stick". PVA with PLA, PETG with PLA, that sort of thing. If you have the same material in both extruders you are back to the single-extruder problem of the support bonding to the print.

One thing I noticed about my nozzles is that they are all the same exterior shape. Whether it's the .20 I.D. or the .80 I.D. the outside diameter of the tip is 1.0. So the .20 nozzle has an "ironing surface" of .4mm all around the inside diameter but the .80 nozzle only has an "ironing surface" of .10mm around the ID. Admittedly I didn't pay a lot for the nozzles and I suppose I shouldn't have expected anything different, but if the .80 nozzle had some more land around the ID I think I'd get a better finish. As it is, even a little bit of over-extrusion wants to sneak past that small "ironing area" and make ridges on skins.

Here's my try. GV Surface-solid Test.3mf

When you use a single extruder printer then there must be an air gap between the top of the support and the actual print. If there wasn't then the support would become part of the print and be near impossible to remove. Adaptive Layers aside, Cura works with a fixed Layer Height and so the minimum air gap is 1 layer thickness. You can play with the other settings but you are going to end up pretty much with what you see in your photos (which really isn't too bad). If your layer height is .20mm and you have a .20mm air gap then you have extrusions calculated for a .20 height that are going into a .40mm gap. They are not going to squish like they would with full support. This is a primary reason people go to dual extrusion printers. Extruder 2 would be for support with a non-compatible material. That means no air gap and the support interface can be 100% density. One alternative is to print separate pieces and bond them together. I use short pieces of filament for locating pins and have matching 2.0mm holes in the mating parts. Location is very accurate and Cyano-Acrylic glue works very well on both PLA and PETG.

Back in the day I was very into U-Control and then RC airplanes and I still maintain some interest. Now I'm retired. I'm too much of a wus to go fishing when it's 40 degrees outside and so I wander into my office a few times a day and check here to see if I can add something useful (or at least humorous). I started working with Gcode in 1969. This allows me to claim that I have some understanding of it. You can find the listing of the Marlin Gcode commands HERE. The RepRap WIKI is a bit more extensive and is HERE. You don't need to know all the G and M codes but some come up a lot and those you should be familiar with. When you install a printer in Cura, Cura uses a "Printer Definition File" which was put together by either a member of the community, or supplied by a printer manufacturer. That file sets certain "maximums" and "defaults" within Cura. Many of those settings can be found when you load the "Printer Settings" plugin from the MarketPlace. Those "Maximums" and "Defaults" assume that the settings within the printer are also the defaults. But many of those settings can be changed in the printer and so the Printer Definition File may not be up to date and so Cura may not be up to date. The only thing those Max's and Defaults affect are the settings boxes in Cura. If a box turns red when you enter a number then you have made an illegal entry (according to the definition file). There is no interaction between the printer and Cura other than a gcode file. If you go to Printer Settings and change the Maximum XY Acceleration the printer will not be told. You would however be allowed to enter a higher number in the Speed / Acceleration settings boxes and it would be accepted by Cura. The only way to tell what the printer settings actually are is to send an M503 to the printer and to view the response. You can do that with "Pronterface/Printrun" or with my "Greg's SD Print Tool" that is a Windows App that I'll include below. Either way you need a working USB connection to use them. I wrote the app for Marlin but many commands cross-over with RepRap. Greg's SD Print tool. Let me know if you come across any issues or bugs. I was only a 3.8 student.

If you set a limit in the printer using M201 then that will be the upper limit. Let's say you set a limit of M201 X1000 Y1000 in the printer. In Cura you ask for 2000mm/sec. That would go to the printer as an M204 S2000 in the gcode. When it gets to the printer the printer would impose the M201 limit of 1000. (Think about what that means for Cura's "Estimate Print Time" when the actuality of the printer is different than the theoretical of the gcode.) This is part of my printers response to M503. echo:Maximum feedrates (units/s): echo: M203 X500.00 Y500.00 Z50.00 E50.00 echo:Maximum Acceleration (units/s2): echo: M201 X3000 Y3000 Z100 E1000 echo:Acceleration (units/s2): P<print_accel> R<retract_accel> T<travel_accel> echo: M204 P1000.00 R1000.00 T1000.00 echo:Advanced: S<min_feedrate> T<min_travel_feedrate> B<min_segment_time_us> X<max_xy_jerk> Z<max_z_jerk> E<max_e_jerk> echo: M205 S0.00 T0.00 B20000 X10.00 Y10.00 Z0.40 E5.00 You can see that my limit in M201 is 3000 for X and Y. In the M204 line you can see that I had Cura set for "Print" and "Travel" acceleration both at 1000. In this case the printer would use 1000 since it is below the limit set in M201. If you set a limit in the printer then the printer won't go over it, but you can set Cura to whatever you want. You can change the limit by adding an M201 line to your startup followed by M500 which would save the setting to make it the new default after which you could remove the lines from the StartUp. If you don't enable Acceleration and/or Jerk in Cura, then the printer will use whatever it has in M204 with an eye on the limit set in M201. For Jerk it will use whatever it has in M205. Jerk is different in that there is no way to set Jerk except by changing the Maximum limit as M205 is the only command that applies. If you tell Cura you want Jerk at 100 it will gladly tell the printer to use 100 and the printer will gladly accept it. My printer is an Ender 3 Pro so it's a bed slinger. If I'm printing something tall and thin I will manually add a M201 Y350 line at about layer 300. That will soften the starts and stops so the print doesn't break free of the bed. When I shut the printer off and turn it back on the default of M201 Y3000 is back in place.

Scale the model to 250% in the Z. Set the model on the build plate and slice it. Look at layer 1. I think you will see that there is no divider until Cura prepares for that wall. This is layer 2 with the model at Z=64.75 tall. No divider. On Layer 3 the divider shows up.

This is X-Ray view in Cura. You can see that there is a problem surface within the model. I didn't notice anything odd when I sliced it though. I was able to repair the model with MS 3D Builder. Is it supposed to look like this? I think the "dividing the first layer" may be because that outboard part is so thin. It's only a couple of layers thick and then the wall starts. I think Cura is preparing for the wall support.

OK that is not infill showing through but Support Interface. I understand. Have you tried printing those with Adaptive Layers turned on? As the bowl areas rise they develop "feather edges" that will want to curl upward. That can often cause a deformed look to certain layers. Cooler temperatures can help and shorter layer heights mean not as much heat is being imparted to layers below.

Good Luck.

I have some analysis tools I've written. I read a gcode into AutoCad to check geometry, and into Excel to analyze extrusions/retractions/Line Widths. Using your 3mf file to generate a gcode everything looks very good. Line Widths are generally right at 0.40mm (there is some variance as would be expected given "variable line width"). The speeds are on the money. I don't see any issues in the "flow". Within AutoCad everything is where I would expect it to be. The layers have concentric extrusions. The side view shows a basic hemisphere. Certainly nothing like what printed for you.

When I zoom in to your images it does look like some under-extrusion. On the bowl in particular, there is very little material covering the infill. Calibrating the E-steps falls under "it can't hurt". Another thing are the black flecks on the bottom of the bowl. Could that be burned material from inside the hot end? Maybe you just need to clean out the nozzle and hot end. A partial clog where the bowden tube meets the back of the nozzle is a popular problem on Creality printers. You could try trimming the hot end of the bowden tube by 5 or 6mm and re-installing. That would put the teeth of the fitting onto new plastic. Make sure it is a nice square cut. I looked at your settings in the 3mf file. They look fine. I would change some things, but they would be "personal preference" rather than something that is amiss. I like higher "support density" and higher "support interface density" when there are arcs and circles. The extrusions stay where they are put instead of getting dragged towards the center.

Yes, you will need to use surface mode. Here we are looking straight down a gap between the internal ribs and the upper and lower skins of the wing. A bit of over-extrusion would glue them together, but not by much.

In Preveiw mode, if you look at the underside of a model you will see surfaces colored red. Those are the areas that will need support (according to the overhang angle you set). Those red areas must be covered by a support blocker in order to block the support. The blocker doesn't need to go down to the build plate, just cover the red surface, or in some cases, part of the red surface. Here there are three blockers that I've made 30mm in the Y There are no supports where they've touched the red overhang surface.

Try it with a 0.4 nozzle at 0.35 Line Width. I thought it looked pretty good. I usually print boat hulls thicker at .8 line width as they aren't near as fussy about weight. If you wanted to print this at 0.6 line width you could do that by jacking up the flow in Cura, or just adding an M221 S150 line to the beginning of the gcode file. If you try to do it with the line width then Cura will skip areas. This is at .35 Line Width. (BTW the bottom of the model isn't flat. That's why the skirt is cutting across short of the leading edge.)

I can guarantee they are not gcode bugs. My Ender never prints like that. Load the model and set Cura up to slice. Use the "File | Save Project" command to create a 3mf Project File. Post the 3mf Project File here. All Creality printers need the E-steps calibrated. Did you do that?

The convention is to use G0 for moves with no extrusion and to use G1 if there is an extrusion. The oddity in Cura is when Z-hops are enabled. It may be because Z-hops are related to retractions/primes and so a Z hop move will be with a G1 even though there is no E value in the line. "Lately however that went away and now it's just +0.2" I think it's a firmware issue. A line like "G0 Fxxxx Xxxx Yxxx Z0.2 should send the print head to Z=0.2. IF there is some sort of compensation for the bed leveling written into the firmware, then the firmware may be adjusting that, but the command states to "travel to Z=0.2". G29 has some parameters that can be applied. Which parameters is likely dependent on your firmware. The same would be true for M420. The Marlin definitions are HERE and the RepRap definitions are HERE. When you use Search and Replace to make changes it has the option to "Use Regular Expressions". That option can make the Search very specific. Search: ;LAYER:1\n Replace: ;LAYER:1\nG0 X0 Y0 Z0\n Use Regular Expressions: TRUE The search criteria with the "\n" newline character would be limited to Layer:1 (rather than Layer:1, Layer:10, Layer:11, Layer:100, etc.) Rather than using the G1 line it might be better to use the "G92 Zx.x" line to set the Z position for the file. That way every Z value in the file would be adjusted. A third possibility would be to use M206 and adjust the home offset Z.

If you are using "Pause at Height" then you have at least two options regarding the actual Pause command. "M0" is the normal Marlin command and should send the message "click to resume" to the LCD. When you are ready to restart then a button click on the LCD should resume the print. An alternative is "BQ/M25". The M25 is "pause SD print". Sometimes the LCD will say "click to resume" but sometimes (depending on your firmware) you may need to click on "Pause" before clicking on "Resume". How the printer reacts to a command is a function of your firmware. If a command is not supported by the firmware then it is usually just ignored by the printer.

No matter how you do it - if you level the bed and the initial "Z gap" is exactly "0" then the line G1 F1000 X0 Y0 Z0.2 would set the nozzle at exactly 0.2 above the build surface. For an ABL system the commands are often: G28 G29 and then either purge lines or printing start. The printer is supposed to go where it's told. If the initial gap is too high (or too low) then there is something going on with the ABL settings and the Z-offset. The only other real possibility is that there is a problem in the Z system that causes the printer to NOT go where it was told, but that has a very low probability. Manual leveling is different. You Auto-Home the printer, level the bed, and then start the print. Almost every printer definition file puts a "G28" in the StartUp gcode. What that does is to reset the Z=0 location. Considering the quality of parts on my printer, I found that the Z=0 was often a different height than the Z=0 of my first Auto-Home. That changed the height of my first layer. The bed didn't move, the nozzle height was changed by a Z-stop switch that isn't very "repeatable". Changing my Startup Gcode to "G28 X Y" solved the problem. The "Z" location I leveled with is the "Z" location I print with.