gr5

I have no idea what you are talking about here. Your printer is defective. I'm pretty sure. Maybe it just needs a drop of oil but something is wrong. So I looked up the A8. You are slipping in the X direction (left/right). It sounds like you don't believe me. To prove it, mark the stepper motor shaft with a sharpie and mark the pulley. Or just tighten the hell out of the set screw on that pulley. If you use an L shaped allen wrench you want to tighten it with the long end going into the set screw and holding the short end of the L in your fingers. It should hurt your fingers. Tighten it very very tight. The tool will almost twist a bit. You are lucky - that pulley is very accessible. On some printers you would have to take things apart just to get access to that pulley. Also put a drop of oil on each of the two rods going through the head. With power off, push the head around and feel the friction for reference for the future.

You can position your part far to the side in CAD and cura will ignore that and center your part every time. If parts aren't defaulting to the center then something is wrong in your printer settings - see "manage printers". Make sure the size of your build area is correct and make sure you have the checkbox correct that sets origin in the corner (not the center - that's only for delta printers).

What kind of software did you use to generate the STL file? There are many possible problems - maybe you didn't connect the top and bottom planes with side walls. Maybe your tiny side walls are facing the wrong way (there is a concept called "normals" which tells the STL file which side of every triangle faces air, and which side faces plastic). You could try fixing it in netfabb repair services (a free web service but you have to create an account). Or try using the mesh plugin in cura. Or you can switch to xray view as that sometimes highlights the problems. You can also look at the mesh options in cura and try unchecking them all.

One of your axes is slipping. I can't tell if it's the X axis (left to right) or the Y axis (front to back) but it's the axis that goes left/right in the lower picture. This is usually caused by loose set screws on pulleys - those have to be tightened to the extreme. Something is slipping somewhere in your hardware. Ask other people who own the same type of printer as you do (what type of printer is that?)

Any light oil will do. I use "3-in-one" oil. "sewing machine oil" is a good choice. Don't use vegetable oil as it will go rancid but any petroleum oil will work. Don't use WD-40 as that is for cleaning things - it's not so good at lubricating.

It's not getting enough time to cool. I usually fix this by printing 3 or 5 of the object at the same time. Right click on the part and select multiply. If your fans are on the side then position the parts in a row left to right. If your cooling fans are in the front or back then position the parts on a line front to back. Alternatively you could print a small tower on either side of this print (that is at least as tall).

So that's a problem with your model. Did you create the model? You need to find an expert in the particular CAD software you used. That's not really a Cura issue. You could try netfabb free repair service (you have to create an account but it's free) or you might be able to fix it in meshmixer. But ideally you want to fix the model.

acceleration is just as important as jerk.

Note that they are reverse thread 🙂

That looks like infill showing through. You have a few options. One is to make the walls thicker - it looks like you only have one pass on the wall so maybe make 2 or 3 passes. Or maybe you already have 2 passes. So set: 1) Wall thickness 2 or 3X line width But probably the easier thing to do is just this: 2) check the box on "outer before inner walls" Note that cura claims this can reduce quality on overhangs. For some reason I don't get these lines without having to do #2 above. Or maybe I get them but they are too difficult for me to see. Note that shiny black filament shows imprefections more than any other type of filament but only if you hold it just right so the light reflects just so. As you did here. If you were to (for example) paint this with a flat matte color you wouldn't be able to see these lines.

Can you zoom out? Are you in "PREVIEW" mode? Is color scheme set to "line type"? If so, then I'm guessing it's something to do with openGL

Well that sucks. I'd buy a set of screw extractors and drill bits and get it out with that. Probably have to drill it out part way as well. Before you do any of that maybe buy some spare parts (spare pulley with set screws). You can lower the acceleration speed and the jerk speed. I think defaults are 20 and 5000. Try 10 and 2000. It will print slower but it will put less strain on that pulley.

Sorry I didn't look at your model but there's something wrong with the model. Maybe the normals are wrong. Go into mesh fixes - make those all visible and uncheck them all - in particular it could be that "union overlapping volumes" needs to be unchecked. If this fixes your issue then this is a hint as to the problem in your model. You can also just run your model through netfabb free repair service on the web (it's free but you have to create an account) or try meshmixer - I think it has mesh repair tools. I think there is also a mesh repair plug-in in cura you can try.

wow. I've never seen anything like that. Can you enable the travels? I want to see which moves are considered travel moves. Did you just slice an STL? Or did you load this from gcode?

Those are non extruding moves so the head can get from one part to the other. In your screen shot I can see you have near the top "color scheme" set to "material color". I prefer to set that to "line type". Then note that you can check and uncheck different things. If you uncheck "travel moves" those lines should go away - which might be bad as then you can't see them but they are still there. Note that it shows one blue color but in fact there are 2 shades of blue - light blue, dark blue. One color indicates that there was a retraction before the move. The other indicates there was no retraction. This matters. non-retraction moves will leak a bit.

What I see in video is if the command was X104 instead of X10.4. I'm wondering it the period in 10.4 is not a normal period - maybe it's some kind of unicode character? Or UTF8? Another thing you could try is just change 10.4 to 11 and get rid of the period.

VERY HELPFUL, THANKS! G1 Z2.0 F3000 ;Move Z Axis up G1 X10.1 Y20 Z0.28 F5000.0 ;Move to start position G1 X10.1 Y200.0 Z0.28 F1500.0 E15 ;Draw the first line G1 X10.4 Y200.0 Z0.28 F5000.0 ;Move to side a little G1 X10.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line G92 E0 ;Reset Extruder G1 Z2.0 F3000 ;Move Z Axis up Well it's definitely the first "10.4" line. This is so messed up! It should not do this. So when the video starts it is in the middle of the 3rd line of code above. F is feedrate in mm/minute. Divide by 60 to get mm/sec. So that F1500 is 25mm/sec. E is the E axis position - it's extruding 15mm of filament while it draws that line up the left side. Again - this is the 3rd line of code above. 4th line: Then it does the crazy move and it's moving faster as expected - at F5000 or 83mm/sec. And you can clearly see that it is indeed about 3X faster. BUT IT'S ONLY SUPPOSED TO MOVE LESS THAN A MILLIMETER TO THE RIGHT. 5th line: then it moves back to the left front corner as it is supposed to while extruding (now goes from 15 to 30mm or extrudes another 15mm of filament - that's the E30). And it's back to 25mm/sec. The video confirms. All is fine on the 5th line. 6th line doesn't cause movement - it just tells the printer to think of this as position 0 for the extruder stepper. 7th line raises the nozzle 2mm - and it's in the video all good. YOUR PRINTER HAS A MARLIN WITH A SERIOUS BUG. There are lots of bugs in marlin. Anyway this is how I would fix it - get rid of the speed change, no need to mention Y or Z since they are not supposed to move (and don't): G1 X10.4 ;Move to side a little If it still moves to the center of the bed - just take the damn command out. It's not really needed. I'm guessing somehow the speed changes is causing the issue but there is no need to speed up when moving 0.4mm - I mean it's not going to make much difference!

Again - for this particular print (PPE mask) - this skip is not even slightly a problem - the next layer will stick really nice. In fact having it a bit thin makes it so the part will stick extra well to the bed and not come loose during a print.

Those skips in that photo are where the nozzle and bed are too close. It's normally hard to tell if you are too close or too far but that (95% sure) is too close. You can verify by pushing up or down on bed/print nozzle with your finger (you only have to move the thickness of a sheet of paper to see a significant difference). So your bed is not flat - not within the thickness of a sheet of paper. Or maybe your gantry is not flat. Most likely the bed. This is okay. You can just choose a thicker bottom layer. Or ignore it - in this case - for this print - it's not a problem at all. Why do other sliced jobs not do this? Well most likely the bottom layer is thicker on the other jobs. Look at the gcode - search for Z - there are not very many of the letter Z in a gcode file - typically one per layer plus maybe 2 to 5 more. Look for the first Z just before things really get going (dense amount of moves). Typically it's around 0.1 to 0.3mm. Maybe the presliced ones have a thicker first layer to compensate for non-flat print bed.

Okay this is so bizarre. It does this *before* it does the skirt? Can you post a 5 second video that shows what happens 1 second before and after it happens? I see nothing of interest in the gcode but I'd like to narrow it down to one or two lines of code and seeing the video would help.

Oh - and again - it's completely fine to just hit the power switch on a UM2 at any time. The printer is tough. It can take it. You will of course have to start the print from the start. Actually there is a "continue print" option if you install tinkerMarlin but that's advanced and not worth it for short 1-hour prints like these.

You can abort I think within the TUNE menu. I didn't check, sorry. So it looks like you had a layer shift to the left. If you look carefully you can see that most of the part printed fine for several layers then it looks like the part is duplicated (in a silly string kind of way _ to the left. In particular there are 2 ear hooks and the wavy-string stuff is to the left for both ears. About 1.5 inch to the left. OIL There are a few possible causes. One is that you just need to oil the rods. With power off push the print head around to the 4 corners. The movement in X and Y should be about the same. You should not be able to push it with one finger but if you use one finger on each hand, try pushing with one finger on each end of the rod going through the head and it should be easy to push it (printer might slide a little on the table but usually not). If the X axis is much worse then this may be the only issue. Anyway use some oil to clean the rods with tissue or paper towel and then after removing all oil add only one (one!) drop to each of the 6 rods in the gantry. Push the head around. If you feel an improvement you might be done. PULLEYS More common (maybe - well quite common anyway) are loose pulleys. They may be fine 99% of the time but when there is a little too much acceleration they can slip. Each of the 12 pulleys have a set screw. Your printer should have hopefully come with a long hex driver with a green and black handle. You need to tighten all 12. Actually just the 6 on the X axis. The 4 pulleys on the long belts are easy with an L shaped allen wrench or the hex driver. Just push the head around until you can see and access the set screws. However the most likely pulley to slip are the 2 on the short belts on the X axis (which are the X axis? just push head left and right and you are moving X axis belts and stepper motor). Those 2 pulleys are the hardst to get to. If you have a hex driver you can do it without taking anything apart. If you absolutely can not make phone calls and get access to a hex driver (2mm hex driver) you will have to remove the cover over the X stepper. There are I think 2 screws holding each stepper cover - screw head is outside printer. Only uncover X stepper (right rear corner). You may have to completely remove the stepper to tighten the pulley set screws. I have never had to do this as I have a long hex driver. TIGHTEN THE HELL OUT OF THESE SET SCREWS! You want it scary tight. So tight that the tool twists. If you are using an L shaped allen wrench it should hurt your fingers. You should see red marks on your fingers after from the short length of the L.

1) Please take a photo. I have no idea what you are talking about. Microfibers? 2) You can just hit the power switch if you want. In the pause menu I seem to remember an abort option. Anyway then just clean things up and start over. 3) PPE is complicated. Are you sure you will be printing a design that will actually be used? There are lots of problems with many of the designs floating around out there. Did you speak to a doctor? Are you printing a design that multiple nurses or doctors approved of. It's great that so many are helping but let's not create things that won't get used.

I had this exact problem (except it was X axis) on a UM2 (not my printer but I fixed it for them). It was hard to tell but they had sprayed some kind of glue or something and it was over many areas inside the build area. Anyway diagnosis is the same regardless. Start loosening the 8 pulleys on the long belts - well really the 4 on the long belts for the bad axis. With power off move various things. For me it was one of the 4 sliding blocks wouldn't budge (the one opposite was fine but that was not obvious until I removed the head and loosened all the pulleys). The 2 rods that go through the print head - pop each end out one at a time from the 4 sliding blocks. Then twist the head and lift it out of the printer and put aside. Once you know the problem area I had to take apart one sliding block and remove the whole rod from the printer. I brought the rod and copper sleeve bearing to some heavy duty tools area and used hammers and vices and things to get the copper part to slide (first clean the rod well of anything on the surface - maybe some fine polishing with 1000 grit or so). Eventually I got the copper part off and was able to clean the two parts until they slid nicely and then reassembled everything.

When inserting and removing right core it is supposed to be lower. But if you then slide the switch on the right side it should go up above the left core. Some things to try - clean the nozzles while hot. Loosen the 3 leveling screws so the gap is around 13mm (you want the springs of the bed to be weaker than the springs in the cores if possible). Check for loose wires inside the print head (open the door and in the bottom there are 2 wires - make sure they aren't loose). Check for loose wires inside the top of the print head (remove rear two long screwd, remove cover, make sure connector is seated, reassemble). Don't touch the printer when it is auto leveling. Keep strong electromagnetic emitters (like a phone or laptop) a meter or more away from the printer during auto leveling.