GregValiant

I use Notepad++. You can open them in regular Windows Notepad as well. You have the "Regular Fan Speed" at 0. Cura is adjusting the fan speed per the setting "Regular/Maximum fan speed threshold" which you have at 10 seconds. When the layer time falls below 10 seconds the fan speed approaches 100%. When the layer time climbs above 10 seconds the fan speed goes to "Regular" which is zero. So what you are getting is expected behavior given your settings. Set that regular speed to what you want it to run at and the fan will stay on regardless of the layer time. You could also set the threshold to 0 in which case the fan will run at that regular speed starting at layer 36 and continuing to the end.

The fan speeds in those gcodes are bouncing all over as the print approaches the top. I've never seen that before. Cura has added an M107 line at layer 94 so yes, the fan is being shut off before the top. With the model loaded and Cura set up to slice, use the "File | Save Project" command and post the 3mf file here. This might be a setting issue. Your "Regular fan speed" is set to zero.

The picture didn't show up. You can't re-order a layer but changing the Z-seam location and/or the Layer Start positions (in "Travel") may allow you to fool Cura into printing the portion you want first. You could also slice with "Relative Extrusion" turned on and then cut and paste sections in the gcode to get the order you want. That's "Advanced Gcode Editing" and I wouldn't advise it unless it's practiced.

Understand that this will clear all files from the SD card so make copies if you don't want them erased. Stick it in the computer, right click on the drive letter in Explorer, select "Format". A "quick" format is sufficient.

That second comment about only printing a partial gcode might be because of bad sectors in the SD card. You could try reformatting it. I have had to do that every few months. You first comment about "extrusion stops" might also be related. I found the hardware to be pretty nice and my printer works well. I just couldn't print anything more than 3 or 4 layers tall as the prints would collapse from their own weight.

I'll look around to see if I can find the files. I'm on a new computer since I played with the chocolate extruder and I'm not sure where the files are. I'll get back. Edit: OK here are the files I have. The instructions are in the ReadMe file. Good luck. My problem seemed to center on the fact that the chocolate wouldn't firm up on the build plate. My next attempt was going to involve inventing some sort of system to suck air across a dishpan full of ice, get it to the intake of my layer blower, and blow it at the extruded chocolate. That seemed easier than buying a refrigerator to print in. At some point I'll probably revisit the thing, but right now I'm still mad at it. Ender3LuckyBotProfiles.zip

In the original model, the reason there is a start point there is because of the pocket. When a wall has air on one side it gets an outer wall extrusion. So the inside of the pocket gets an outer wall backed by 2 inner-walls to make up the proper Line Count. The 4th side (that closes the pocket) is 0.40 thick so it gets a single wall. That makes it impossible to make a loop around the inside without coming to a stop and restarting again. The nozzle can extrude it left to right, or right to left, but if it tries to put the pocket in, the nozzle dead ends where it's already been. The addition of the Outer-Wall-Only model gets ride of the situation because it doesn't have the pocket, and neither does the main model. Making that short wall 2X line width wide would also get rid of the problem as the nozzle could make a full loop for the inside of the pocket and then a continuous loop for the "real" outer wall. This is the project with your fix. At the top near the blue arrow notice that the outer-wall of the inner model is thinner than the outer-wall of the outer shell model. This is significant because the variable line width of Cura will adjust to make that single wall section to it's dimensional width of 0.4mm. That's how the situation in the circles arises. You can see that it isn't a single extrusion past the pocket, but rather one extrusion ends, there is a flow adjustment, and at the end of the pocket wall that extrusion ends, there is an adjustment back to the original flow. That's going to leave two slight lines on the print. In this image it runs between the yellow lines and you can just (barely) make it out. How visible it is depends on the printer and how smooth it can make the transition. In the case of this model it really shouldn't be noticeable. On some models it can look like another Z-seam.

The geometry of the model dictates that there will be a seam for that pocket. With the model at the midpoint of the Cura build plate, set the "Z-Seam Alignment" to "User Specified" and the "Z-Seam Position" to "Back Left". Here is how I oriented the model in Cura. If you place the model differently then the "Back Left" would change.

There is a plugin in the MarketPlace called "Settings Guide" that provides the full explanations with pictures and arrows explaining each one. So go to the MarketPlace and install it, quit Cura, and when you restart it should give you the expanded explanations when you hover over a setting.

Can you install any printers in Cura? All of the information for all of the 300+ printers is in the resources folder. If you can load a printer, the folder must exist. If no printers are available then it might well be a bad installation.

Here is the gcode in Cura with a Kobra as the active printer. The gcode reader is a separate program from the slicing engine so it shows a true and accurate representation of the gcode file and there it is in the middle of the build plate. There are two build plates to deal with. The real one on the printer and the virtual one in Cura. They have to match or things can get wonky. Measure your build plate and subtract 5mm from the width and 5mm from the depth. In Cura - Click on Settings, Printers, Manage Printers and then on Machine Settings. The settings "X width" and "Y depth" should be pretty close to what you measured. They are probably a bit less than your calculated numbers but that isn't a problem. Auto-Home your printer and then raise the Z a couple of mm's. Move the nozzle to X = 1/2 of the X(width) listed in Cura and Y = 1/2 of the Y(depth) listed in Cura. Is the nozzle at the midpoint of the bed?

I'm an amateur and a hack at writing code but I've been doing it (poorly) for over 50 years. I don't remember how many apps I've written to communicate over the serial port with various devices. It was a lot. From ski racing timers to load cells to a 60 ton Baldwin Universal Test Machine. There were even some numerically controlled puppets in there. They all had 1 thing in common...they were slow (especially the Baldwin). The difference I see with 3D printers is that the data needs to flow at varying rates or you will get buffer under-runs or over-runs at the printer. Under-runs will cause blobs and over-runs will drop command lines. In addition there are thousands of combinations of 3D printers, PC's, USB ports, port drivers, and firmware. The fact that it works for you is nice. It just doesn't work for everyone because really, it can't. There are just too many combinations of "stuff" to account for. I always had 1 PC talking to 1 specific device. I didn't appreciate that at first so I tried my hand at an app to be a print server and send gcode over the USB to my Ender. After about a week of fooling around with it, the entire project ended up in the toilet. So I copy the gcode to an SD card, stick it in the printer, sit down with my "Greg's Toolbox" app that talks to the printer. I ask the printer to list the files on the SD and then I tell it which one to print. Nice. If the print needs some tuning, no problem, I click on a slider and run the speed up a couple of notches and hit a button to send M106 S255 to the printer. It says "ok" and keeps motoring along. The LCD is totally out of the loop except to resume after a pause. For that I have to hit the button, but that's the only thing I need it for. That's a good thing because it was really the clumsiness of using that button for everything that I didn't like. Because I always leave the printer plugged into the PC - if I'm printing over-night I kill the internet connection so Microsoft can't send an update that will restart the PC and reboot the printer. Another thing you might consider is that the "Power Loss Recovery" data is written to the SD card. If you don't have one in the slot then there is no chance to recover a print.

Is this a bug (or is it a test)? link is to: https://github.com/Ultimaker/Cura/releases/tag/5.6.0-beta.1 rather than: https://github.com/Ultimaker/Cura/releases/tag/5.6.0

The Z seam is best at one of the stern corners. The prize for answering your own question is that you get to figure out where to put the Z-seam on this one. 3DBenchyDoubleEnder.stl

The directory structure is different but the names remain the same. In Windows the folders are in: C:\Program Files\UltiMaker Cura 5.5.0\share\cura\resources. Then it's the "definitions", "extruders", and "variants" folders. You might have "quality" files as well.

There might be a way to do this. It's clumsy and I wouldn't do it myself, but you can try. As you have found - if a Com Port is busy then Cura won't connect to it. If "USB Printing" is in use by one instance of Cura then a second instance of the same version can't use it because the plugin is busy. That is the key. If you use a different version of Cura, and if you time the connection to the printer just right, it will connect. With one USB connected from the PC to a printer, start Cura 5.5.0. After a few minutes it should connect. After the 1st connection is established - connect the second printer to the PC and start Cura 5.4.0. After a few minutes it should connect. Here I've got 5.4.0 connected to an AnyCubic on Com 8 and 5.5.0 connected to my Ender on Com 9. Notice that the hot end temperature box is missing from the 5.5 instance. I don't know what's up with that and hitting "cancel" doesn't bring it back. I pre-heated by sending M104 and that worked fine. I'm using a port emulator and a null modem cable as a virtual AnyCubic (which is in reality another PC). It appears you could actually print like this as my experiment worked. I will stress that I said "YOU" could print like this...I would never. I agree wholeheartedly with AHoeben. Other than being a semi-interesting exercise it's just something I wouldn't do because USB Printing is glitchy with even a single printer hooked up. So I went a different way. I wrote a "print server" app and it will control up to 10 printers at once. But it doesn't print over the USB ports. Instead, you select a file from the SD card in each printer and then tell the printer to print it. Switch to another printer and do the same thing. I can switch back and forth between printers and tune a print, pause, or abort from my laptop (which could look like an "decopus" if there were 10 USB cables connected). That all seems to work quite well because I'm not actually printing over the USB, just sending commands to control the different printers. Take none of that as gospel. It could all just be the rantings of an old man. Seems to work though. Time for more coffee.

Turn on the "Custom" settings. Under "Build Plate Adhesion" will be "Build Plate Adhesion Type". The options are Skirt, Brim, Raft and None. When set to "None" you shouldn't get a skirt. You can also set the number of laps of a skirt. The default is 3 laps but you can set that to 1.

This is the "UltiMaker" forum and that Gcode was not created with UltiMaker Cura. That being said, there are no commands in the gcode that would shut off the hot end or bed prior to the gcode ending and that gcode should print just fine. The printer should do nothing without being told. At the beginning of the Gcode it is told to heat the hot end and bed (the M109 and M190 lines do that). Then at the very end of the gcode it is told to turn off the hot end and bed (M104 S0 and M140 S0). There are no commands in between that affect the temperatures. Sorry, but this seems to be a problem with the printer. You haven't used it in a while so open up the mainboard housing and check all the connections. An UlitMaker Cura file starts like this: ;FLAVOR:Marlin ;TIME:26477 ;Filament used: 51.777m ;Layer height: 0.2 ;MINX:1.32 ;MINY:1.422 ;MINZ:0.2 ;MAXX:227.279 ;MAXY:228.578 ;MAXZ:7.6 ;Generated with Cura_SteamEngine 5.5.0

That's the basic boilerplate StartUp Gcode. There isn't anything in there that would cause a problem. Cura adds a prepend before that section in the gcode and the prepend has the starting temperature commands in it. Printing over the USB can be very glitchy. Try printing from the SD card and see if the problem occurs that way as well. You can open the Gcode file in any text editor and search for M104 and M109. You may find an M104 at the end of Layer:0 and it will be M104 S200 (or whatever your print temperature is). You can also search for M140 but I'm sure the only one will be at the end of the file in your Ending Gcode. This problem has happened with other printers but I can't remember if they were Longers or another brand. A search of the forum might bring up posts about the problem. You could zip and post the gcode here but the problem is likely with the printer.

I don't know that printer but there are a couple of things that are common to all bowden tube printers. If a gap forms between the bottom of the bowden tube and the back end of the nozzle - hot plastic can be pulled into the gap making a little "O-ring" that can impede the new plastic coming in. Pull the filament out. Carefully trim back the end of the bowden tube by 5 or 6mm with a razor blade taking care to make an exact 90° cut. Push the bowden back into the hot end ensuring that it is flush against the back of the nozzle and then install the locking clip onto the holding fitting. As the machine goes back and forth in the "X" it will cause the bowden tube to rotate in the hot end fitting. No way around that. Additionally, every retraction pushes the pulls the bowden into those little knives. Over time, the little knives in the fitting will work down into the plastic of the tube allowing it to move up away from the back of the nozzle causing the gap. This is the reason that bowden tubes are considered to be an expendable part as they get shorter every time they are trimmed. Make sure your retraction distance isn't overly long. On most bowden printers a retraction distance of 6.5 is OK but the "max retraction length" is something that can be specific to each printer model. Long retractions will pull molten plastic up into the heat break causing a partial blockage. Heat Creep Make sure the hot end fan is working whenever the machine is printing. Take the hot end cover off and inspect the fan blades and the fins on the heat sink. They can collect strings of filament and won't work as well as when they are clean. That allows the heat from the heater block to move up into the heat break (between the block and the heat sink) causing the filament to soften and fold. That appears to be what is going on with your filament pull. Smashed filament If you have an adjustable spring tensioner on the extruder arm, and if the spring is putting a lot of pressure on the filament it can cause the filament to deform and get wider than it should be. Constant retractions across the same spot of filament will make it worse. That makes in harder and harder to push the filament through the bowden tube. When you pull the filament it has a characteristic "accordion" look. Loosen the spring tension. Cooking the filament can happen if the filament is sitting in the nozzle for a while and you are printing very hot (for that material). The filament can char and little pieces of char can break free and clog the nozzle. The nozzle would need to be removed and cleaned out. Those are the main things. Now you have something to do today.

Yes - all the flows should be the same. I have my printer tuned to PLA but I have found that PETG likes the flows at 105%. I could change the E-steps/mm to account for that, but then I'd just be moving the flows down to 95% for PLA. So it just doesn't matter. Because the layer height doesn't change and the extrusion length is what it is - when you make a flow adjustment the Line Width changes. So you could get some variation in the dimensions. At 0.40 line width if you change the flow by 10% you will get a change of 10% to .44 for the Line Width. For an outer wall that has an inner wall already in place next to it, that extra .04 of width is all to the outside. That is not a big change but is is a change of possibly .08 across the print. (I see more change than that if I put the print in the sun.) I'm not happy with the Flow Equalization Ratio. It makes changes to the Print Speed to account for the flow changes that come from Cura varying the line widths and I'm seeing really out-of-whack speeds because of that. There are several bug reports on Github in regards to the speeds. You can just leave it at 100% since it doesn't really have anything to do with the general flow, just flow that is being changed due to line width variation. I set it to zero because I'm mad at it. I haven't seen any real difference in the prints but I don't get print speed adjustments to the 300mm/sec range anymore.

Did it all wire up correctly? The unit itself is fine. Well made and complete. It just made a mess. It's been a while since I played with it. Something did happen at the beginning and it wouldn't extrude but I seem to recall I made a simple change and it worked. It has to be closed and up to temperature and the steps/mm need to be correct. You also have to disable the "Cold Extrusion Preventer". I found the config files if you want them. The startup gcode has to include: M302 S0 ; Turn off Cold Extrusion Preventer. M92 E750 ; set the Esteps/mm

"The post-processing scripts ... assuming that they work at all." I don't want to toot my own horn, but I might be the best at post processing scripts that barely work. I don't collect them per se. They just magicly appear from the ends of my fingers.

One thing to consider is that Simplify, PrusaSlicer and Cura calculate volume-of-extrusion slightly differently. Cura considers a simple rectangle LayerHeight x LineWidth x Length. PrusaSlicer considers that the left and right wall of any extrusion will be a radius What I've read is that Simplify adds a simple fudge factor of a couple of percent to the LH x LW formula. The differences are subtle, but there. I've looked at your profile and there are a couple of things that are frankly personal preference, but it's because I didn't like the results I got when I use them. "Coasting" is at the top of the list and "Retract Before Outer Wall" is on the list. They both effect the start of the next extrusion. My Ender doesn't like them. I get filament from Matter Hacker. It is consistently 1.72 diameter. I enter that into Cura's Printer Settings because at 1.75 diameter I would be suffering about 4% under-extrusion right-out-of-the-gate. Top skins are the best for checking "flow". I picked up a microscope at a garage sale for cheap but a decent magnifying glass will work as well. What @Dustin and I are seeing in your image are gaps between the extrusions of the top skin. If you zoom in you see that the edges of the extrusions are not welded together and you can see the cross-hatch pattern (of the layer below) through the gaps in the top layer. That is definite under-extrusion and when you add a bit of material shrinkage, you get the gap you see around the hole and material being pulled into the center of a circle. The simplest thing to do is increase the flow in Cura. The project below has a FlashForge Dreamer NX as the active printer as it is the only FlashForge printer that was available in Cura. There are three identical models with different Per Model Settings. The model on the left has the flow at 100%, the middle model has flow at 110% and the right model has the flow at 115%. I set the Line Directions to [0, 90] to make it easier to check while they are printing. Open the project and switch to your printer. I started out with your MyDraft profile but go over all the settings to insure they are what you have been using. Watch during the print and when they are done check the top surfaces with a magnifying glass and see what you see. I don't know your printer, but pretty much all Creality machines must have the E-steps/mm calibrated in order to produce the correct volume of filament for extrusions. If you can or have calibrated the E-steps then DO NOT use a "single wall calibration cube" to further alter the flow. Just insure that when asked to deliver 100mm of filament the extruder does actually deliver 100mm - no more and no less. Flow Test Cubes.3mf EDIT: This is an exaggeration but it's what I'm seeing in your images. Notice that you can see the layer below through the gaps in the top layer.

@Torgeir hasn't dropped in lately but he's pretty good with the 2's. Maybe he'll respond and have a thought on this. The title says the printer "randomly restarts". After reading your description it sounds more like it "randomly stops". Would that be correct(?) or is it restarting the print from the beginning and double printing those first couple of layers?