GregValiant

When I slice the file - those under-extruded areas on the left are occurring just before the outer wall finishes at that far left corner. In the project file you have "coasting" turned off, but that under-extrusion looks like what happens with coasting enabled and the coasting volume is set too high. I have never printed that material, but it looks as if the extruder is running out of gas at the end of those extrusions. The red line indicates a single layer that under-extruded. The blue arrows indicate areas that look good, and the yellow arrows are the under-extrusion. Looking at the layers, there is no difference in the toolpaths between the blue arrow layers and the yellow arrow layers. They all circumnavigate the model with the layer start and end at that left corner. The under-extrusion is occurring at the end of the loop. That c'bored hole interrupts that toolpath as the model becomes 3 islands and those extrude correctly. Then when it turns back into a single toolpath all around the model the under-extrusion appears again. These are general suggestions. I would turn off "Retract before outer wall", "Avoid printed parts when traveling" and "Avoid supports when traveling". All of those can contribute to "dry starts" of extrusions (admittedly, that doesn't seem to be the problem as the nozzle is traveling right to left in that image). If you are having trouble with the nozzle knocking supports over then enable "Z-hop on retraction" as an alternative. My Ender 3 pro is much better with PETG when I slow down the retraction and prime speeds to 25. It's as if the material doesn't like being snapped back and forth at the nozzle. If you pull air into the nozzle during a retraction it will take a bit to get going again. Have you tried printing that material at a higher temperature? 195 is kind of low and the material may be stiff at that temperature and has trouble getting moving. I see you have your "initial layer print temperature" at 240. That's a really wide spread from 195 for the rest of the print. Sorry I can't be more helpful. Not having any experience with that material is a definite handicap.

In order to keep the "first layer over support" from sticking too badly to the support structure, it is necessary to have an air gap. The airgap means the "first layer above support" doesn't get enough squish. If you have a true "dual extruder printer", then you can change materials for the supports and interfaces to something incompatible with the model material so the model won't stick to the interface. The airgap isn't required and the interface can be 100% density. That appears to be the main advantage of dual extruders. Water soluble PVA support material would allow you to dissolve the supports. Those "first layers over support" you have in that model look pretty darn good to me. With a single extruder printer it really doesn't get any better than that.

@Slashee_the_Cow has been printing a lot of TPU. Maybe she has some thoughts on this. If it was me, I'd print two halves and glue them together. That would get rid of the entire "horrible support surface" problem. Super-glue works well with PLA/PETG but I don't know about TPU. Some sort of bonding agent should work though.

Did you happen to load the "StartUp Optimiser" plugin from the MarketPlace? I think it hides machine definitions to allow Cura to start faster.

I HATE when things are "not always". If "M0" doesn't work on your printer then using "M25" the way you have it is the next best option. I don't see anything actually wrong with the code. You are using "M109" for the "resume temperature" command. M109 can cause a 10 second delay even if the temperature is up to the set point. Since your standby temperature is "0" and because of the M109, the printer may not actually be pausing. It might just be taking a short break while waiting for the temperature to come back up. Unfortunately this is a firmware problem. You will need to keep experimenting to find a combination that works with your specific printer. There have been certain Creality printers that (along with the "M0 doesn't work" problem) require that after pausing with M25 the user must select "Pause" on the LCD before selecting "Resume". Even on those machines the M25 in the gcode does pause the print. I would make a couple of suggestions. You need to confirm that the printer is actually pausing and that it isn't just the temperature command faking you out. (it's part of that "not always" thing). Make sure the "Disarm Timeout" of the steppers is at least 1800 seconds. You should see M84 S1800 in your gcode just before the pause command. Set the "standby temperature" to your printing temperature of the next material. Use M104 as the "resume temperature" command. Slice something small and do a pause at a low layer. You can pull the filament out of the printer so you don't waste it. Then print the new gcode and watch to see if it is actually pausing. It should just sit there waiting patiently for a button click on the LCD. If it is still sitting after about 10 minutes, then it paused. If it just stops for a bit and resumes by itself then the M25 didn't really work. One of the oddities about "M0 doesn't work" is that other commands that send messages to the LCD don't work either. That means your M117 buffer-fill lines could be a problem. Use M105 instead. It doesn't send a message to the LCD, it just asks the printer to report the current temperature.

Neofil 3D makes filament in a variety of materials. Is that PLA, or something different???

PLA is easy to print, very brittle, and doesn't hold up to hot environments very well (or at all). PETG, ABS, or a couple of more exotic choices up to carbon-fiber filled nylon are possibilities. Some are very difficult to print without a heated build chamber and a filament drier. Let the physical size of the parts determine nozzle size and layer height. The small parts should be fine with a 0.4 nozzle while the larger ones will print faster with a 0.6 or even a 0.8. The grain of the print will be coarser. You might want to print some parts in PLA just to see how it goes. It's the cheapest and you can check how parts fit together before committing to print them with anything more exotic. You can get "heat set" push in inserts from Amazon or McMaster-Carr. They are handy-dandy little gizmos. I have a small electronics Weller soldering iron. I've made a couple of custom tips for it for pushing the inserts in. McMaster has drawings of the holes that each insert would require. Some are tapered holes. If the holes are too small the insert can push molten plastic in front of it during installation. That requires some cleanup. If the holes are too big then the inserts don't grip as well. They aren't really fussy, but you have to pay attention.

I think you will need to revert to Cura 4.13.1 to fix that. The Arachne engine of Cura 5.x adjusts the line width along the holes. This 5.6.0 and looking along the wall you can just make out a variation at the hole. Here in 4.13.1 that little bump isn't there. I've never been able to tune that out of my prints. Horizontal holes aren't to bad (as long as you know how to sand). Vertical holes can have a ridge on either side of the hole as Cura adjusts the line width and has to move the nozzle over when that happens. Here the line width adjustment has caused Cura to use three lines to get past the narrow wall where the hole is near the outer wall of the model.

I'm going to go with Slashee on this one. Looking through the "first layer over support" the next layer is under-extruded as well. Looks to be 40 to 50% under-extruded. A lot of extrusions weren't staying where they were put. @Bumb3bum - Along with the obvious "calibrate the E-steps" check in the Cura Machine Settings and make sure you don't have the Gcode Flavor set to "Marlin Volumetric". Volumetric works fine if both Cura and the printer are set for it. If only one is set that way then the extrusion volume won't be read correctly by the printer.

They are HERE. I haven't kept up with that one. UM just closed a lot of "slicing error" reports so there does appear to be some improvement due to show up in 5.7.

@Torgeir is lazing in the sun someplace but he might have time to look at this between pina-coladas.

Welcome to the forum. @Dustin of UM may know of classes for owners of UM machines. For the rest of us it's mostly "jump into the deep end" and sink or swim. A couple of questions... What printer(s) do you have access to? What materials will you use for printing? You will need to adjust the models for 3D printing. Simply scaling them down will cause features to "disappear" because they get too fine to print. You can see them in the model, but the line width of the printer simply can't be adjusted small enough to print them. Things like window mullions, small overhangs, landscape trees and bushes, supports for walkways, etc. don't lend themselves to 3D printing. My guess would be that making those sorts of adjustments was a big part of what your cohort was doing. You must think "fun scale" and not "exactly to scale".

The teeth on the extruder drive gear are sharp. They bite into both materials pretty much the same so I don't think that's it. It might be shrinkage as it cools but I don't have a way to check that. Dimensionally there is no difference in the prints. Visually I can tell (I picked up a microscope somewhere along the way) and that is where the 105% came from.

PETG is so soupy that the first layer over infill always wants to sag into the infill gaps and the sparser the infill, the worse it gets. I use the fan for that layer and the results are much better as the PETG hardens before it can sag much. I have written this post processor (it will be included with Cura 5.7) and you can turn the fan on for a single layer and then turn it off again. PETG generally doesn't respond well to cooling, but a little can help certain problem areas like the first layer over infill. Unzip it and put the AddCoolingProfile.py into the "scripts" folder in your Configuration folder. (You can find it by using the "Help | Show Configuration Folder" command.) I print a lot of PETG. My printer E-steps are calibrated for PLA and I have found that setting all the flow numbers in Cura to 105% helps with PETG. Since the filament diameters measure exactly the same I have no idea why that is, but it works. AddCoolingProfile.zip

I've seen this in my own prints. This is your project. (I've set the line width to .10 and forced compatibility mode for the view. I think it's easier to see.) It's obvious that the behavior extends into the skirt as well as that wall of the support structure. This is snippet of the gcode. It's as if Cura is stepping the line into a series of orthographic moves instead of a single long "point A to point B" move as would be expected. G1 X645.935 Y286.278 E153.93243 G1 X645.941 Y286.843 E153.99585 G1 X645.994 Y287.368 E154.05509 G1 X646.105 Y287.925 E154.11884 G1 X646.266 Y288.469 E154.18252 G1 X646.464 Y288.956 E154.24154 I didn't find a way to get rid of it either. I have not seen a bug report on Github that mentions this. You can go HERE and click on the "New Issue" button to fill out a bug report.

In the material settings all of your flows are at 90% except for the Initial Layer. You are asking Cura to under-extrude by 10% on all layers above the Initial Layer. Your line width is at .35. That's OK but your "Skirt Line Width" of .30 is too small for a 0.4 nozzle. Then you have the "Initial Layer Line Width" at 130%. Here is a generic PLA project for your printer. Only adjust the Print Temperature and Bed Temperature to your favorites for PLA or PETG. The print speed is 50 from the second layer up so it would be suitable for either material. The point here is to see how the printer performs with a bland base profile. (BTW - I didn't care for the stock "Kobra Max" profiles.) Here is a project file. It's a flattened 50 x 50 rectangular shape. The setting profile is a new one I named "GV Test". GV FlatCube.3mf

With Cura set up to slice, use the "File | Save Project" command. That will create a special 3mf file that will have the model, all your settings, and your printer in it. Post that 3mf here. It's really hard to tell what might be going on just from the images.

That's an Ender 3 of some sort, correct? Slashee has a couple and I have an older 3 Pro. If there was some sort of binding in the bowden I would expect it from right to left rather than fore and aft. The bowden flexes with X movement rather with Y movement. I think you are on the right track though. Just because I think X movement binding problem is more likely doesn't mean your printer agrees with me.

I have to revise my comment "I just don't see a point to it. The extra 3 or 4 minutes isn't going to hurt anything.". I only print PETG and some PLA so for me, that comment is OK. Neither material is prone to "cooking off" in the nozzle when there is no movement. On the other hand, there are some materials that don't like to sit there cooking and can start to break down inside the nozzle. In the case of a material like ABS (that needs the bed very hot) waiting until the bed gets up near the set temperature before starting the hot end could be not just useful, but necessary. I really like this new feature of some logic being done in the startup. I always had a second printer installed just for TPU because it needed really slow purge lines. Now a single printer can adjust it's Startup so it can be used regardless of the material. G1 X1 Y200 F{speed_print * 60 * .75} E15

If (for example) you use a custom profile that was based on "Standard" (or "Draft", or whatever) then that last portion of the Cura Gcode file would show all the differences between your custom profile and base profile that was used to create it. If you happened to use "Standard" with no changes, or if your custom profile used for the slice happened to be the same as "Standard" then the final paragraph would be empty. If you go to "Manage Profiles" and then "Import" - down in the File Type box you can select Gcode Files. When you import a Gcode as a profile, Cura will pull what it can from that final paragraph and build a custom profile. You can switch to that profile but you would still need the model so you would have something to slice. The final paragraph cannot be post-processed because it is inserted into the Gcode file after the post-processors run.

Cura adds the temperature prepend lines before the startup gcode if there are no "cura keywords" in the startup for the bed and/or hot end. It's a safety to guard against cold extrusions. Go to Settings, Printers, Manage Printers, and then Machine Settings. The startup gcode is in the left text box. Add the lines I've added in bold type: M221 S100 ;Reset Flowrate M140 S{material_bed_temperature_layer_0} M104 S{material_print_temperature_layer_0} M190 S{material_bed_temperature_layer_0} M109 S{material_print_temperature_layer_0} G28 ;Home That will heat both units simultaneously. Putting in a "dwell" to slow down the faster heating device can be done but it's not very useful. When I print PLA with the bed at 50, the hot end and bed finish heating at about the same time. When I print PETG with the bed at 83 the bed heats a lot slower when it gets over 55 so the bed takes about twice as long to get to the set temperature. I suppose I could stick a logic line in there. Something like: {"G4 S180" if "PETG" in material_type else ""} I just don't see a point to it. The extra 3 or 4 minutes isn't going to hurt anything.

I think the failure on part #2 happened when the support failed. You have the "hoop" of the model near the edge of the bed. Cura noted that and sized the trunk of the tree support to fit in the room it had. Here I've placed one model closer to the edge than the other. You can see that the trunk of the tree on the right is much more robust and less likely to fail. It looks like you had Z-hops enabled at 0.2. Try increasing that to 0.5. If the nozzle hits a skinny support (like the left model above) there is an excellent chance that it will knock it over and cause a failure. In regards to the under-extrusion, I don't know what to make of that. Here it looks like the supports failed because of under-extrusion. That also seems to have been a problem lower near the build plate. As you noted, the good part doesn't show that. If it was me, I think I'd print a couple of scaled up (in the Z) calibration cubes with one in the front of the bed and one in the rear. The point would be to try and duplicate the problem. It isn't likely that the problem is in the gcode but rather with the printer. On another topic - infill. Everybody likes gyroid but at low densities it fails. These extrusions are too far apart so they don't connect to the previous extrusion. More spaghetti. The first skin over this infill will be ugly as it will be mostly printed over air. I understand you are weight sensitive here, but the part has to have some strength.

That's really odd. Set the project up again in Cura and use the "File | Save Project" command and post the 3mf project file here. Somebody will take a look. What material is that?

Sunny Sarasota? It's been raining here in Venice for the past 3 weeks but the sun is trying to break through now. It looks like it will be cool and drizzly for at least the next few days. I guess it could be "El Nino".

That code is more suitable to a printer with ABL, but there are no ABL codes (G29 or M420). You are pre-heating the nozzle. When the print starts the "M104 S140" line is setting the hot end to 140. With an ABL system that would be nice so the nozzle doesn't drool on the bed as the ABL does it's thing. You don't want that if you are manually leveling the bed. After auto-homing (G28), the "M109 S{material_print_temperature_layer_0}" line should set the hot end back to the Initial Layer Print Temperature. "M109 S" means "set the hot end temp and wait for it to be reached". Even though the temperature is dropping to 140 during the startup, that Startup gcode should work. If you are manually leveling I think this would be more suitable. It will work whether you are pre-heating or not. I suggest that you install another instance of your printer in Cura and test this startup gcode. ;-------------StartUp M220 S100 ;Reset feed rate to 100% M221 S100 ;Reset flow rate to 100% G21 ;Metric Units G90 ;Absolute movement M82 ;Absolute extrusion M140 S{material_bed_temperature_layer_0} ;Start the bed heater M104 S{material_print_temperature_layer_0} ;Start the hot end heater G28 ;Auto-Home G92 E0 ;Reset extruder G1 F{speed_z_hop * 60} Z10 ;Move up M190 S{material_bed_temperature_layer_0} ;Wait for the bed temperature M109 S{material_print_temperature_layer_0} ;Wait for the hot end temperature M300 P250 ;Short beep G1 F{speed_travel * 60} X10 Y0 ;Move to purge start G1 F{speed_z_hop * 60} Z0.3 ;Move to purge height G1 F{speed_print * 40} X160 Y0 E30 ;150mm Purge line at 2/3 print speed G1 F{retraction_retract_speed * 60} E28 ;Short retraction G1 F{speed_z_hop * 60} Z0.4 ;Move up a little G1 F{speed_travel * 60} X150 Y0 ;Wipe the nozzle G92 E0 ;Reset the extruder ;-------------End of StartUp Since you are pre-heating (to level I presume) you could do without the M190 and M109 lines. Each of them can cause a 10 second delay as the printer decides if the temperature has been reached. They are there as a safety to insure that the bed and hot end are up to temperature before any extrusions. The Marlin commands are HERE. I suggest you look up the ones that appear in your Startup so you understand what they are telling the printer to do. The Cura keywords are HERE. Cura Keywords must be enclosed in curly brackets. The "speed" words are " * 60" because Cura uses mm/second but gcode uses mm/minute.