GregValiant

Welcome to the club.

A support blocker must cover the overhanging feature that Cura thinks needs support. Then don't always go on the build plate. This first image has the support blocker on the build plate. You can see that the support is still generated for the upper part of the model. You can't see it in this image but the lower portion of the model doesn't have any supports. In this image I've moved the support blocker up. You can see that the lower portion of the model is still getting support generated (the blocker is too high to affect that area whereas in the image above it was covered and not supported). You can see that the upper portion no longer gets supports.

I don't know Octoprint but from what I've read it can be configured to send some commands and sometimes those can interfere with a print. If you didn't enable the G2/G3 commands in your firmware then ArcWelder cannot be used. The reason is that when a G2/G3 command is read by the printer it gets ignored. The result is that the next move is from (what is now) the wrong location to a new location. If there are a lot of G2/G3 commands in a row then that distance can be a long ways. G90 just sets the printer to Absolute mode. The normal situation is for the Startup Gcode to end with the printer in absolute movement mode (G90) and absolute extrusion mode (M82). If you are using Relative Extrusion then Cura should add an M83 after the end of the StartUp Gcode.

@andymharrison - Use the visibility dropdown tool (next to the settings search box) and then go to the Mesh Fixes section. The only thing you might want checked in there is "union overlapping volumes". Sometimes "remove all holes" gets checked and sometimes "make overhangs printable" gets checked somehow. Those are specialty settings that are for very specific situations that rarely come up.

Post one of those "bad" gcode files here. You can also use "File | Save Project" to create a 3mf file with your settings, the model, and your printer and you can post the 3mf file here as well. Are you using USB Printing or Octoprint? Are any post-processors being used? As long as you didn't use ArcWelder you can check the gcode file yourself by opening it in Cura. The Cura gcode reader is separate from the slicer and you will get a good view of where the gcode is telling the printer to go. I can read the file into AutoCad even if ArcWelder was used. That takes Cura totally out of the loop for "post-viewing" a gcode file. You may have a corrupt SD card. Formatting usually fixes that. The fact that the PrusaSlicer files were OK kind of eliminates that possibility though.

Load the model in Cura an set up to slice. Use the "File | Save Project" command to create a 3mf file with the model, settings, and printer and then post that 3mf file here. It's the easiest way to remotely troubleshoot.

I have a second Ender 3 Pro installed in Cura for TPU. The StartUp Gcode is the only difference and that was to account for the print speed of the purge lines.

@kaptonit - What @BigBlue says will work. When Cura notices that there are replacement patterns (keywords) in the StartUp Gcode it does not put the initial "M104/M109" or "M140/M190" in front of the startup gcode. If you alter your StartUp G-Code and call out the temperatures like this you will get the bed and hot end to heat together. This example is for a printer with ABL and is meant to keep the nozzle from oozing as it moves around during the Auto-Level sequence. M104 S160 ;Start to heat the hot end but keep it below "ooze" temperature. M140 S{material_bed_temperature_layer_0} ;Heat the bed to Initial Layer Bed Temp M109 S160 ;wait for the hot end to hit 160 M190 S{material_bed_temperature_layer_0} ;wait for the bed to get to temperature for layer 0 G28 ;Auto-Home if required G29 ;Auto-Level command M109 S{material_print_temperature_layer_0} ;wait for the hot end to get to initial layer temperature before trying to extrude any material.

Good morning @adlong and @ahoeben. Adlong - One typo can ruin your whole day and two can make things twice as difficult. G1 Y5.1 X200.0 Z0.28 F{print_speed] E15 ; Draw the first line There are two things here. The ending square bracket is one typo and is interfering with ALL the replacements. {print_speed} doesn't exist as a keyword. {speed_print} would work but it's in mm/sec rather than mm/min. What you are trying to do can't be done at this time. There are a couple of requests on GitHub for a replacement keyword in mm/min but it hasn't happened yet. What it appears you want is for the line to read: G1 Y5.1 X200.0 Z0.28 F3600 E15 What you get with the curly brackets fixed and "speed_print" inside will be: G1 Y5.1 X200.0 Z0.28 F60 E15 which is 1mm/sec and will be extremely slow.

Remove the line G28 X\Y\Z as it is unneeded. The line ;G92 E0 is a comment (semi-colon in front). Your extruder location is at some random location and when the first extrusion of the print is read by the printer it is moving to (for example) from whatever E location the processor knows, to E0.0123 or something. that results in a long retraction. I suggest you uncomment that line (remove the semi-colon) and see how that works.

Load your custom profile. Make all the settings visible. Go to Mesh Fixes and make sure that "Remove all holes" and "Make over hangs printable" are de-selected. The only thing that you might leave checked in Mesh Fixes is "Union overlapping volumes".

If you search this forum for "Flashforge" you will come up with several threads discussing using Cura with those printers. This thread includes video instructions for one of their printer models.

Search this forum for "Creatbot" and some discussions will come up. THIS thread is interesting. It may not be directly helpful for you but it could point you in the right direction.

I worked on my N gauge layout for 25 years and never really finished it. I'm actually proud of that since it was a good hobby for a long time. I can see where a 3D printer would have been a nice addition to the tool box. Nothing digital here and a block system rather than radio control. I must admit that sometimes I'd get a bit confused and the result was often a Gomez Addams moment. There was no room for it when we moved to Florida. I just about gave it away.

I think you will need to design a custom support brim and add it to the model. This photo shows a 1mm custom brim. You see the chamfer I added at the part line to make it easier to trim off. The chamfer is .4mm thick at the bottom of the chamfer so it has a bit more strength. It worked well. If you do something like that you can cover both problem holes.

On the left in Per Model Settings is "Print as Support". Any model or support blocker can be set.

You have it as a "Cutting Mesh" and it needs to be an "Infill Mesh". No walls, no top, no bottom, infill at 100%.

Next to my right foot was an electric motor somewhat larger than an automotive starter motor. On the other side of the front fascia of the truck but directly connected to the front of the motor shaft was a 12" diameter Federal Siren. Directly over my head was an air horn. It wasn't good enough for me so I found a second "robust" air horn and added it. Over on the boss's side was a very large bell. Fortunately, it was mounted outside on the bumper. My boss loved that friggin' bell. I would drive through the streets of Detroit in this lime green and white 1974 Seagrave 100' aerial ladder truck with the siren screaming and the air horns (both) blaring and my boss yanking on the rope and clanging the bell. I would do that an average of 8 times a day, 4 days a week, for 12 years. When I was younger I enjoyed rock concerts. Now we jump forward from "young man" to "old man". When I first started printing on the Ender I had thought it was kind of loud so I went and replaced all the cheap fans with good quality ball bearing fans. The new fans made a huge difference in the noise level. About 2 weeks ago I finally broke down and purchased hearing aids. Now with the hearing aids in - I can finally appreciate what my wife has been complaining about for the last two years. DAMN THIS THING IS LOUD. AM I SHOUTING....YES....BECAUSE I HAVE TOO IN ORDER TO BE HEARD OVER THE DAMN PRINTER! A "Sound Abatement" enclosure is in order. Putting a sound abatement enclosure around the printer because the noise bothers me means that; now, with my much improved hearing, I will never hear the end of "I told you it needed that two years ago!".

If you add a support blocker and scale it to say, .4 thick, and set it to print as a normal model, then you can place it adjacent to your real model so that it become part of the real model. If you were to scale the X and Y large enough you could make your own raft and then place your model on top of it. You could load the "Tab Anti-Warping" plugin from the MarketPlace and play around with that as well. The anti-warp tabs are round and are commonly called Elephant Ears.

@Produktdesigner... The stock hot ends of Creality printers are very susceptible to partial plugging at the nozzle end of the bowden tube. It has several contributing causes and usually becomes a problem on long prints. The end of the bowden tube was not cut exactly square and so there is a gap between the nozzle and the tube. Retractions then pull molten plastic into the gap creating a point of high friction that while not bad enough to cause missed steps it certainly causes poor extrusion. Heat Creep. The stock hot end cooling system is barely adequate. The fans Creality installs (all four of them) are really poor quality. As the X moves back and forth - the bowden tube rotates in the retaining coupler at the hot end. That causes the little knife edges within the coupler to bite further into the tube which in turn allows the tube to back away from the nozzle which creates a gap which in turn allows molten plastic to accumulate where it doesn't belong. Just about the only known fix is to replace the hot end with a brand name unit. Replacing the fans is a very popular upgrade both for the noise reduction and for the performance.

Thank you @nallath. The poor old Visual Basic guy stands corrected. @AndreaG85 I almost forgot... Print time can be hugely affected by retraction/prime speed and the retraction distance. One poster here was complaining about their print time. It turned out they were retracting 7mm at 1mm/sec and so every retraction/prime took 14 seconds. Z-hops can also have a large effect depending on the number of retractions. A Z hop height of 1mm would take somewhat over .1 seconds to complete at 10mm/sec so that is .2 seconds for an up-down move. A medium print might have over 5000 retractions with Z-hops in it so that would be an additional 9 minutes for 1mm Z-hops. It all adds up.

@nallath would be better to ask since he is part of the Cura team. I'll try to stumble through what I believe to be true. Cura has a standard printer definition file called "fdmprinter.def.json". Almost all printers start with the settings in that file. If you were to install a Custom FFF Printer in Cura it is the file Cura uses to start you off. The files are in "...\Ultimaker Cura 4.X.X\resources\definitions". There are also Extruder definitions and Nozzle (variant) definitions. Then a manufacturer comes out with a new printer model and when they (or an owner - a "member of the community") test it with Cura they find that the settings are not optimal. So the manufacturer or owner creates a printer definition file specific to that model printer. Whoever created that definition file then submits it to Ultimaker for inclusion in Cura. Cura supports over 300 printers. Printer definition files are Python files and can be opened with a text editor like Notepad and they can be altered (carefully). If you alter a definition file (like in your case increasing the Machine_Max_Speed_E) then the next time you were to re-install Cura or upgrade your Cura version, it would revert back to the definition file that comes with Cura. You can always go back, copy your custom file, and paste it into the new Cura folder. The next time you start Cura it will read in the current definition. So this is from your Mega S definition file "anycubic_i3_mega_s.def.json": "version": 2, "name": "Anycubic i3 Mega S/Pro", "inherits": "fdmprinter", "metadata": { "visible": true, "author": "Nils Hendrik Rottgardt", The line "inherits": "fdmprinter" indicates that the definition does indeed start with the generic definition. You also can see that the author has signed their work. In regards to the author - I'm pretty sure he does not work for Ultimaker as that would seem to be a conflict-of-interest. As I like to note; "Open Source" does not equate to "Non-Profit". If you scroll through the code of your definition file you will see a lengthy "overrides" section. Those are the changes that your specific definition file makes to the generic settings of "fdmprinter.def.json". You may notice that there is no override for "machine_max_feedrate_e" but there is for "retraction_speed". My guess is that when your printer firmware was installed it included a Max E Speed of 40mm/sec and the Author knew that. You can change that in the printer by adding something like "M203 E50" to any gcode file you print. If you were to follow that line with "M500" then the setting would be saved and become the new default within the printer. (You might also be able to make that change via the LCD menus). You would also need to change the setting in Cura's Printer Settings so the printer and Cura match. Again...unless you tell Cura about your printer, it doesn't know what you have. That is the basic function of a definition file. My printer is a Creality machine. The definition file is "creality_ender3pro.def.json" which inherits "creality_base.def.json" which in turn inherits "fdmprinter.def.json". In Creality's case they use the basic "fdm" printer definition, then make changes for their entire line of printers, and then make specific changes for my printer. I have in-turn customized all three of those files (along with some others) and when I upgrade Cura I have a separate installation routine I run to copy all my custom files to the new version of Cura. This has been a two cup-of-coffee post. I hope I got some of it right.

That model hates "Cubic Subdivision" infill. Grid and Triangles and a couple of others looked good, but I'm not sure what you are looking for. That mesh modifier you have over the "smoke stack" is better at 22 x 22 and moved a bit. It's cutting off a piece of the stack. The large mesh modifier doesn't appear to have any settings enabled.

@MikeM70 if you would post that on Github it will get proper attention. They will need your Cura.log file as well. It will be in your ...\Users\UserName\AppData\Roaming\cura folder.

Something didn't go right. I can't load that file. Load your model, set Cura up to slice and then try to create the 3mf project file again. You can attach the STL file as well.