GregValiant

There are settings that can cause areas to "disappear". If you post a 3mf Project File (File | Save Project) it would be very helpful. Is the Outer Wall Inset = 0 ? Is the Horizontal Expansion = OFF ? If you try slicing with a smaller nozzle (or line width) - does that area slice? Is the model watertight?

I've read a lot of posts about clogged nozzles. I truly don't think I ever had one. It's always been a partial clog at the back end of the nozzle. A gap between the bowden and the nozzle is the most likely suspect. Some hot ends are fussy about overly long retractions. You can trim back the bowden tube by 5 or 6mm's. It needs to be a nice square cut so it will seal at the back of the nozzle. Put the nozzle in first (the hot end needs to be up around 200° to remove the nozzle and to re-assemble it) and leave it loose by 1/4 to 1/2 turn. Shove the bowden tube back in and make sure it's down all the way. Put in the locking clip and then tighten the nozzle up. Don't over-torque it as the heat block is soft aluminum and is easy to strip.

If you are in the Perspective view you can go to "Preferences/Configure Cura/General and in the Viewport Behavior box is "Zoom towards Mouse Direction". It doesn't work when in Orthographic but it's fine when in Perspective. Those settings are in the General section as well under Camera Rendering.

Because the definition isn't included with Cura, you will have to manually install the definition. Read that previous post again. It isn't a difficult task. I am on Windows and when I update Cura I always have to "share" the installation folder with myself before I can copy anything into it.

Because you have ArcWelder enabled - Cura can't preview the Gcode file. I can read the Gcode into AutoCad but it doesn't show me were the Z seam is. With the model loaded and Cura set up to slice - use the "File | Save Project" command and post the 3mf file.

Something else to think about... When I first started out with my 3 Pro, a LOT of lint, and dust, and filament strings, collected on the wheels. I would clean them off occasionally just using a cloth and isopropyl alcohol. The wheel slots were cleaned the same way. About a year after I got the printer, I heard a squeak. I pulled the wheels off each axis in turn and spun them to check the bearings. There were a couple on each axis that were glitchy. Since the bearings aren't sealed, I sprayed each generously with WD-40 and spun each vigorously to flush out the bearings. I blew each out with an air compressor, worked in a light lubricating oil, and the "glitchiness" and the squeak were gone. That has become part of my preventative maintenance routine. I pull the wheels every 4 months or so and check the alignment of the axes to make sure nothing has changed. Does it help? I don't know. It makes me feel better though as I know if I have to troubleshoot a condition - the axis alignment and wheels aren't the problem.

Well...that isn't good. Either the glass is out of a carnival funhouse, or something is wrong with the Y wheels, or the Y beam extrusion. I'll think on this, but all you did was move the machine? It's hard to believe that something as robust as the main Y extrusion would have a problem and you have been over the wheels a couple of times. You have closely inspected the Y trolley grooves? No mouse in there? How does it print? Is the first layer sticking or is the error too much?

Monoprice explains it HERE. It looks like you add a Custom FFF Printer and then make the alterations that Monoproce suggests.

With Cura set up to slice that model - use the "File | Save Project" command and post the 3mf file here. It looks like it was all good until it gets above the thick portion to the single wall. Remember that there are no circles, just a bunch of line segments that imitate a circle. A consequence is that depending on where the triangles are in the STL file the wall width can vary because it isn't truly concentric. That could be causing the starts and stops. A couple of settings that you can adjust and see if they help are the Line Width and the Mesh Fixes "Maximum Resolution". A higher resolution can remove some of the really short line segments that might be creating the problem. A narrower line width (like .35 instead of .4) can eliminate the slicing problems that can occur when the wall thickness falls below the Line Width.

I've been know to "Fix it till I break it". There comes a point when you have to stand back and say "I'm Done". That point should generally be before the Harley Tool (also known as a BFH) comes out.

I'm not understanding what you mean. A picture is worth a thousand words. The "Virtual Build Surface" in Cura (Machine Settings X(width), Y(depth)) must match the actual "Printable Area" of the build surface on the printer. The Creality definition file will make it 220 x 220. For that to be true - the Home Offset position must be at a point 7.5mm in from the left edge, and 7.5mm in from the front edge of the build surface. My Ender 3 Pro glass bed measures 235 x 235. It has a 1mm bevel all around (non-printable area). In addition, I want another 1.5mm safe area all around. That means I have a 2.5mm non-printable area around the periphery of the glass. 235 - 2.5 -2.5 = 230 and so in Machine Settings I make the bed 230 x 230. I Auto-Home and then move the Z up 5mm. Measuring with a ruler, I move the nozzle to a point 2.5mm in from the left edge and 2.5mm in from the front edge of the glass. I drop the Z back down to 0 and then select "Set Home Offsets" on the LCD followed by "Save Settings". When I tell the nozzle to move to X=230 and Y=230 it will be 2.5mm in from the right rear corner of the glass. If your Y switch is mounted too far forward on the Y beam, it will limit how far back the bed can travel. After Auto-Homing, the nozzle should be close to the front edge of the bed in the Y (and in the X). With the printer turned off, pull the Y forward as far as it will go. The nozzle should be very close to the back edge of the build surface.

The first one is correct. The height of the eccentric nut - not counting the height of the eccentric diameter - must be equal to the height of the spacers on the other wheels. If they aren't then the X plate may rest at some small angle, but it will always be the same as it moves. The same is true for the Y wheels. There is always some tolerance in a switch (and the ABL gizmo is a switch) if for no other reason than "switch bounce" of it's internal contacts. That should be so miniscule that you can ignore it. If you start with a couple of premises: The glass is flat. The nozzle moves exactly planar. Every G28 changes the location of Z = 0. That Z location is totally dependent on the repeatability of the Z switch. I had to swap my Y and Z switches because the Z was off by up to .5mm from one Auto-Home to the next. It made the variation of the first layer thickness really hard to get right. Now I Auto-Home, then level, and the Startup Gcode has G28 X Y so the Z doesn't Home (or change) between leveling and the start of the print. It's a lot more consistent than it was. Leveling the bed manually moves the bed to the plane the nozzle travels on when Z = 0. It should be even-steven all the way across. It's a plane. The ABL measures the plane of the top of the build surface and calculates where it is in relation to the plane the nozzle travels on. Somehow (magic may be involved) an adjustment is made so the first layer is correct. That adjustment does nothing to fix an angled plate or X axis. The parts will be skewed however slightly, but they will print. You did mention the X beam and that it is tight. How about the Z wheels? An Auto-Home causes the Z to move. If there is something that is causing the right end to lag behind the left end, or to hang, then the X will be at a slight angle and the bed leveling data will reflect that.

The only problem I can envision with the eccentrics is if the cam outside diameter isn't engaged into the hole in the bracket. That has happened on my re-assembly a couple of times. Other than that, tight is tight and any clearance tolerance between the offset ID and the shoulder bolt OD should go away as you tighten the eccentric nut. It's how they work. I don't have an ABL so I'm hampered here. Did you manually level the bed before testing the ABL? I know it will make adjustments to the first layer to compensate, but your pattern sure looks like the bed is lower on the right.

@Torgeir and @gr5 are good with those. Maybe one has a dual extruder definition file you can borrow. I added extruders to my Creality definitions so I could at least play with a "virtual multi-extruder" printer in Cura. It required changes to the definition file and the addition of extruder files. I doubt that I'll ever add another 3 extruders to my printer, but things are ready if I do. The Creality firmware is simple and doesn't care about added extruders. Ultimaker firmware may require some tweaks? @tinkergnome didn't mention that but he would likely know.

When you re-assembled the printer - did you use a tri-square or other tool to insure that XYZ are all at exactly 90° to each other and that the faces of the 20x40 Z uprights are parallel? In particular, my Y was at an angle to both the Z and X axes as assembled by Creality. That lead to both leveling issues (I hand level) and skewed prints. Any piece of glass is pretty flat. The X wheels could have been a problem as the nozzle is supposed to move smoothly across a plane. The bed cannot have any wobble that might be caused by improperly tightened wheels on the carriage.

My story is similar. The stock hot end on my Ender 3 Pro was fine for about 6 months of heavy use, and then bingo, constant clogging at the gap between the hot end and the bowden tube resulting in under-extrusion. I found a coat hanger that was the right diameter, cut off a piece, and I'd dismantle the hot end and shove the coat hanger down through it. It always pushed out a plug of plastic that should not have been there. That plug was causing a restriction in the flow. My best guess was that the friction it was causing was the problem. The extruder did not miss steps but my prints were a spider web. So I bought a direct replacement hot end that was a clone of the stock hot end. I did the Auto-Tune and adjusted the PID and then 2 or 3 hours into a print - under-extrusion. This happened every time. I had changed the bowden fittings to the fancy ones from McMaster Carr. The tube itself is a Capricorn. The extruder is fine. I came up with this saying: "When you clone a POS you should not be surprised the clone is also a POS." So now I have an all-metal hot end, a 4015 ball bearing fan blowing on it, a baffle inside the hot end cover to aim the air at the heat sink, and two 10mm holes drilled into the backplate to let the air out. The problem has been fixed and the machine prints as it should. A speed test shows it can put down plastic without a problem up to 175mm/sec with a .4 nozzle. It isn't maintenance free and every 30 to 40 hours of printing I pull the bowden out of the hot end and trim it back 5 or 6mm, clean the nozzle (although I don't believe I've ever had a "clogged nozzle") and run that same piece of coat hanger through the heat sink and heat break. It always pushes out a piece of plastic but it is greatly reduced from what used to be there. I finished an 8 hour print yesterday and it came out beautifully. To answer your question regarding small nozzles, the answer is NO. Because of the Fluid Dynamics of the flowing plastic, there is a lot more back pressure with a .2 nozzle compared to a .4 nozzle. The same is true if you compare a .4 to a .6 or .8. The material clings to the inside wall of the brass and there is a transition zone between the material that is stuck to the wall and is barely moving, to the material in the center core of an extrusion that is moving right along. That transition zone is always the same thickness but on a percentage basis, it is a much higher percentage of a .2 than it is of a .8. We see the same issue in air flow through a carburetor or water through a fire hose (both of which I am intimately familiar with). "All-Metal hot end". The nozzle size doesn't matter, but print speed does so if you want to print with a .2 nozzle you have to slow down. The E-steps must be calibrated. Yes, the hot end needs to be near operating temp when you change nozzles. You can try to push the print temperature in an effort to maintain print speed, but it's a band-aid fix and can have it's own side effects. It prints so well that I decided I deserved a beer and a cigar (the bracket is an IPod mount for my motorcycle). The baffle on the hot end keeps strings out of the blades. Go ahead and zoom in. You won't find many errors.

There ya go. Fixed. Thanks for getting back and letting us know.

@gauthier - What printer are you trying to add the extruder to?

Yes, it's in there. I have a 3mf file you created as well as the gcode. I've written it up on GitHub (#11401). The error is on all the even numbered skins both on the bottom and on the top. I see it was Cura 4.13.1 but they will want to know what Operating system. If it's a MAC then what processor, and if you know the video system then pass that along too. Here is a screenshot from AutoCad. The magenta lines are doubles. You can see that it starts at the lower right, goes to the middle, and then restarts at the lower right before continuing across to finish the skin.

The problem is your Creality firmware. Commands that send a message to the LCD (M0, M1, M117, M600) simply don't work. I think it is a problem with the printer processor communicating with the TFT style LCD on the newer Creality printers which Creality seems disinclined to either acknowledge or fix. The workaround is M25 (which doesn't work on my older Ender 3 Pro) or using G4 to do a timed pause. I have a 4.2.7 board sitting here and those commands don't work. It will continue to sit here until I bother to figure out how to compile my own firmware. Oh Yeah...when pausing from the LCD my printer shuts off the hot end and bed. I forgot because it bothered me so much that I wrote my own pause routine into my printer control software.

It might be a bug. 4.12.1 and 4.13.1 seem to be fussy when the line width and the model wall thickness are exactly the same. Sometimes it's because a round model isn't really round and the facets of the triangles that make up a curved surface in an STL can't be "concentric" and so the thickness varies by small amounts. It might also be a "rounding off" thing in the internal math in Cura. I'm guessing here as I don't really know. On that particular model, MS 3D Builder found a minor error but it didn't seem to affect slicing. The model is of high enough resolution that I don't believe there should have been a problem - but there was.

"0" in the "Standby Temperature" box will turn off the hot end just before the pause. After the pause Cura will add the M109 Sxxx to resume the temperature at whatever temperature you were printing before the pause.

Nice.

I got Cura 4.13.1 to replicate this. Turn off "Print Thin Walls" and set the Line Width to .399 or set Horizontal Expansion to .001 and it should be good. This is with Print Thin Walls turned on and Horizontal Expansion at 0.0.

The draft shield takes time to print. At the bottom and the top of the model - the skins take time to print. So what is going on is that you are bumping up against your "Minimum Layer Time" and Cura is calculating the speeds for the intermediate layers so as to maintain the Minimum Layer Time (and with a nod towards the "Minimum Speed"). If you want to maintain the speed across all the features then you might want to add either the draft wall, or a sacrificial calibration cube to insure that all layers take more than the Minimum Layer Time. If the layer time is too short then the plastic doesn't have time to harden and the print can turn into mush. To calibrate "Flow": Calibrate your E-Steps/mm and make adjustments in your printer as necessary. Measure the exact diameter of the filament and enter it into Cura. Look at the prints and let them talk to you. Any other "flow calibration" is at best confusing and at worst just plain wrong as very few real-life models re-create the exact specific conditions of a flow model. If an extrusion requires 5mm³ of plastic then the printer should deliver 5mm³ of plastic and not 80% or whatever number some "Flow Model" told you it should be.