GregValiant

When I first moved to Cura 4.7 I noticed a fall in print quality. Curves and arcs were very blobby, and I didn't know what had happened. About the time that 4.8 came out I read a blurb someplace that explained that the Creality printers weren't capable of handling the fine resolution settings contained within the Cura machine definitions for the Creality printers. The main problem was with the Mesh Fixes | Maximum Resolution of 0.05. An adjustment to 0.4 made a huge difference in the quality around curves and arcs. The number of extremely short line segments was reduced and my printer/planner was able to keep up with the information flow and the stuttering went away. This is the same type of thing that gr5 is talking about. All the printers are at least slightly different and in my case the settings were causing way more calculations than the printer was capable of handling in the time allotted for the moves and so it would stop and wait for the calculations to complete. Every stop left a blob. That was about curves and arcs and may be an issue with your cylindrical models. Another thing is the Zseam on cylinders. I leave it in a line. If I need to remove it it's easier to do with a file or sandpaper if all the blobs are in a row. There are different problems that occur in straight lines because resolution likely doesn't come into play. There have been many posts on Reddit where I see that a machine was put together by the proud new owner and not enough attention was paid to those parts that came pre-assembled. The number 1 problem are machines that haven't been squared up. The number 2 problem is not checking that the wheels and belts are adjusted correctly. Any wobble in the print head (X) or in the table (Y) results in position inconsistencies and the nozzle doesn't follow the exact same path from layer to layer. The result is that the layers aren't quite on top of one another and you can see that in the finish of your walls on that print. The problem with loose belts is similar in that the stop positions can vary and when the print head takes off in the new direction it isn't quite at the correct point in space. It's inconsistent. I only bring this up just in case @Torgeir, @wjbdesign, and @gr5 didn't give you enough to think about today. Good Luck, and remember "Everything affects Everything".

"The fixed model doesn't have it" That makes it sound like it was indeed something in the model. If that's true (and it looks to be so) it was very subtle. I didn't see anything in X-Ray view, Cura couldn't find anything, and 3d Builder didn't find anything. The only real reason I sent it to Netfabb is that those types of artifacts are often in the model, and I'm hard-headed. The fact that the file expanded from 39 to 98kb is telling us something but I have no idea what the message could be. Subtle. Your settings look fine. There are things I would change as a matter of personal preference, but you know your machine.

I couldn't duplicate that so I wonder if that is just an artifact in the preview display? I checked the model for errors using the Cura mesh analyzer and MS 3D Builder and no errors were found. I uploaded it to Service.Netfabb.Com for repair anyway because sometimes it finds things that other programs miss.. Your file is 39kb and the repaired file I got back is 98kb. I have no idea why that is but I'll pass along the altered model. Maybe somebody else here has an idea, but I'm leaning toward a glitch in the preview. If you save the gcode file and then open it in Cura is that strange pattern still there? 1853057440__fixed.STL

I guess you can just eyeball it. I use a carpenter's tri-square sitting on the bed. The hot end needs to be square when looking from the front and when looking from the side.

@Torgeir, if you open the gcode in Cura it won't be displayed correctly because of the G2 and G3 commands that Arc Welder puts in. Even the skirt displays as a mess. I can't use my AutoCad macros to read it for the same reason. I'm stuck with just the image to make a determination from.

The gcode contains all the machine information (Temps, Accel, Jerk, etc) and ALL the moves. Printers don't "ad-lib". As Labern says, that does look like the Zseam. The settings for the Zseam are under "Shell". By setting it to "User Specified" and "Back Right" (any corner really) and "Hide Seam" it will get put someplace a lot less noticeable. There is always a Zseam. It shows up in Preview as a line of short travel moves going up the part. A couple of other things that have an effect are Combing Mode and Outer Wall Wipe distance. They can cause extra movement at the Z seam location. Retract at Layer Change can cause blobs at the Zseam because a prime occurs there. As an aside - have you calibrated the e-steps on your Mega? I ask because it looks a little "blobby" on straight runs. That particular model has essentially zero arcs and circles so using "Arc Welder" doesn't have any real effect. It can't hurt anything, but it doesn't help either.

There are no guarantees but this should work. You must have "USB Printing" installed and enabled in Cura: Close Cura. Turn off the printer and disconnect the USB cable. Power on the printer. Let it finish the "boot-up" process. Plug the USB cable into the printer and computer (it doesn't matter which end goes first). The printer sees the 5 volt signal from the USB cable and likely will do an "external reset" which will look a lot like it's re-booting. Let that finish. Now the printer knows it's connected and the computer should also notice it's connected. Start Cura and it should notice the printer is there and open the port for communication. There are no further controls in Cura for handling the port. If the default port parameters (baud rate, parity, stopbits, etc.) don't work then you are SOL because they can't be adjusted. I have a program I wrote that handles all communication with my printer. It's very handy and I never have to use the knob on the LCD and my printer is connected to the computer all the time. I NEVER print via USB. I could print via USB but I don't because it's a poor choice.

EDIT: You're quick. That looks like something doable. Wear a mask. I figured it would be. Much like hand coding in that regard. I was a tool designer and one of the places I worked at had a build shop attached to it. There was a big CNC cutting torch machine. Programming a rectangle was easy, but if there were radii involved the center point, radius, and included angle, and start point all had to be programmed for each radius. PITA and the operators hated when we passed along a detail that required radii (we're talking about cutting 3000 x 3000 x 150mm thick steel machine bases). Sitting on the side unused was a laser "follower" that simply followed the lines on a drawing and the torch mimicked the moves. So I started plotting the shapes with wide lines and at 1/2 or 1/4 scale and we'd stick them under the follower and the torch would hum merrily along. I got free beer for about a month after that one.

A Laser cutter, waterjet, or possibly CNC router software would seem to be the ticket. There are people who have used Cura for laser work. There have been questions here asking about what command to use to turn the laser on and off (instead of extruding). Maybe you can find a forum those kind of folks hang around and ask the question there. Somebody will know.

Is that a new nozzle as well? I've had some bad ones that had burrs on the end. You replaced the hot end...is it straight up and down? If the nozzle isn't exactly square to the plate then one direction will extrude differently than going in the other direction. Cotton candy fuzz is evidence of that. Another thing to check would be to make sure you aren't getting any leakage out of the top of the heat block where the heat break screws in. Usually the blobs are a lot bigger but a quick look can tell if it's a problem.

Maybe you should post that over on Github. It looks to be a worthwhile addition. Is there an advantage to using Volumetric vs Linear? It seems like it's just an internal math thing.

Next to the settings search box is a drop down for setting visibility and one of the options is "All". You mentioned "Minimum Support Area" and you have that set to 30mm². I suggest you set it to 1mm². Set the Support Overhang Angle = 55°. This should never be higher than 60° and anything below 45° never needs support. Your layer height of .1 is usually for really fine detail work. These are mostly personal preferences of mine that you might consider. Support - Support Floor Interface and Support Roof Interface make it easier to get the supports out. A grid at 33% works well. I usually use mouse ears instead of a raft. There is a plugin for "Tab Anti-Warping" in the market place. Stick one of appropriate size in each corner on the build plate. There are three round holes on each side of the model. Do you really need support in them? I would use support blockers in there. No matter what you do there will be small flats on the bottoms and across the tops. It's a 57 hour print. Good Luck.

If you are allowed to share that file then go to File | Save Project and save the resulting 3mf file here. Along with the model it will have your printer and your settings in it.

If you can post the STL file somebody can take a look. I would guess that the surface of the chamfer is flipped the wrong way and it is indicating to Cura that it is an inside surface. You can upload the STL to Service.Netfabb.com. You will need to sign up for a free account. It's a pretty good repair utility and takes but a minute and your file is ready to download.

Jeez. It took me way to long to figure that one out. I believe that qualified as a senior moment for me.

The developers of the 3D Builder app in Windows seem to have done a fine job. This is the OBJ file opened in Cura and shown in X-Ray view. As Nallath and Kmanstudios indicate, it's a real mess. I loaded the OBJ in MS 3D Builder and it spent a while repairing the file. I saved it as a 3mf file and opened that in Cura. There are three separate pieces that make up the car. Whether I left them Grouped, or Un-Grouped them, it sliced and I think it looked pretty good (considering what a mess it was). I generally hold Microsoft in low esteem but somebody did some good work on 3D Builder. The attached 3mf file is an export from Cura with the parts Un-Grouped. EDIT: Two of the three models that make up the assembly are the mufflers. GV_F10M5Chasis.3mf

I've never heard of this one. First thing is to use the drop down menu to the right of the Search Settings box. Set the visibility to "All" and then double check on the settings in "Infill". If everything looks good there then you may have to re-install Cura. As I say, I haven't seen this so I'm guessing here.

Well @ultimaker_user, as usual, Torgeir gives good advice. You can try his methods to see how much you can improve the finish. Unfortunately, FDM uses layers to put the plastic down. Those layers are going to have a thickness. Yes, you can lower the layer height to .08 (or if you're really brave, maybe .06). There will still be steps...they will just be lower and therefore less noticeable. If you want it smooth you need to hand finish it. You can get sandpaper down to 4000 grit at an auto-parts store or you can use a high filling primer and paint to get it perfectly smooth. Right now I'm printing a model that is essentially a 100mm diameter ball. I'm using adaptive layers but there are going to be steps. The larger the radius, the more pronounced the steps. It's the nature of the beast and in the end that puts an absolute limit on the finish you can get from the machine.

You can use the post-processing plugin "Change At Z". That plugin does have some issues (the "By Height" option does not work well with adaptive layers or Z hops - they confuse it) but the "By Layer" option will work fine. The second issue is that "Change Bed Temp" does not work with "Target Layer Only". That shouldn't be a problem with what you're trying to do. So under "Extensions" select Post-Processing and Modify G-code. In the dialog that comes up select "Add a Script" and pick "Change At Z" from the list. Within the Change at Z options select "By Layer" and then "Target Layer + Subsequent Layers" and then enter the bed temperature you want to finish the print at.

"...and got totally tangented to a stray thought that took over." @kmanstudios, I don't know where you are or where you are from, but here in the States we call that a "Senior Moment". A long time ago a couple of people (Greeks?) tried this with wax wings. They liked how they came out but during the party afterwards, they got too high.

There are benchtop router systems and CNC milling machines. There are also laser etching attachments for 3D printers. I'm not sure what they use for slicing/cutter paths. Cura works with solids as represented in an STL or 3mf file. Within a CAD program you could try to draw a hollow rectangle with a .4 wall (becomes the Cura Line Width) and extrude it .2mm (which would be the Cura Layer Height. That might result in what you are thinking about. But you'll have to play with the dimensions because sometimes Cura sems to give me a "what are you wasting my time for" response. On the other hand for a simple square that has the left front corner at 0,0 and using "absolute" moves the code is G1 F24 ;set the speed G1 Z10 ;Move up to 10 G1X100 G1 Y100 G1 X0 G1 Y0 The same rectangle in "relative" moves would be G1 F24 ;set the speed G91 ;set relative positioning G1 Z10 ;Move up 10 from wherever you are G1X100 G1 Y100 G1 X-100 G1 Y-100 G91 ;set back to absolute positioning If you are working with straight lines you could lay your path out on a piece of graph paper and hand scribble the Gcode. Once you get into curves and circles you really want computer help.

@Flutelab - I'm sure you're aware there should be 4 lines for the temperature visible at the top of the material section. In the visibility dialog you have open what do the information circles tell you? ("This setting has been hidden by the active machine and will not be visible"???). When you use the search bar with Temperature as the criteria does anything come up?

You'd have to ask one of the Cura Team. @nallath should they all be visible?

Next to the Settings Search Box is a drop down for setting visibility. One of the options is "All". Have you tried that?

The primer line is in the Cura start Gcode. If you just put a semi-colon in front of the lines from "Move to start position" to "draw the second line" they will be treated as comments instead of commands. Take a really close look at the mechanics of the printer again. Make sure that nothing wobbles, there are no loose screws, the print head and the table just move back and forth nicely on the wheels with no weird movement, the glass is going to stay where it's put, that kind of thing. Even the hot ends have been known to come loose on these. It's in the printer and I highly doubt that it's the firmware that is responsible for the shift. There is no feedback loop on these to tell the printer/processor "OK, I'm at X,Y,Z,E". Instead, the processor knows how many steps were sent and where the axes locations are supposed to be. It just keeps merrily translating gcode not knowing that something has changed position.