Cura missing characters after slicing

[param-mehta 0]

Hi. When Cura is slicing my model with 3D extruded text, some characters tend to go missing. I am trying to print a guitar pick with text and a hole above the text to put in a keychain. Please see the pictures. The hole is missing once the same model is sliced. Any reason why this is happening? In other cases, entire letters go missing. I'm using a 100 micron layer height with 50 mm/s print speed. Thanks

 

 

[donmilne 2]

Try turning off the "Fix Horrible" options in Advanced Settings. If your model is watertight then these should't be needed.

 

[pm_dude 27]

switch to the latest Cura 14.12.1. The 14.09 has a tool path bug which causes a lot of extra retractions that you should not need.

 

[peggyb 170]

made the drawing in SketchUp?

look in the view mode tab (top right) at the x-ray view if there are some red spots.

 

[gr5 2,172]

As peggy is hinting - anything in red in xray view has extra inner walls that you need to remove. Sketchup is horrible with this problem.

Sometimes playing with the 4 "fix horrible" checkboxes will let you fix the letters without having to fix the model in cad.

Also if letters are too thin (<.8mm) you may have to cheat and tell Cura that your nozzle is actually .35 (and shell width a multiple of nozzle e.g. .7mm). Or smaller than .35mm.

 

[param-mehta 0]

@DonMilne Thanks for the suggestion. Unselecting combine everything in Fix Horrible fixed this problem. @pm_dude I'm on it. @PeggyB Yes this was created on Sketchup. I'll start using the x-ray view more instead of just relying on the layers view. @gr5 Great tip. I often have a requirement for small text. What is the smallest text font (in mm height) that I can get in the UM2?

 

[gr5 2,172]

I recommend Arial font because it has a consistent width unlike some fonts which get fatter and skinnier. Nozzle/sheel width of .3 looks fine so I would say minimum of .61mm wide. Keep in mind that as you go around corners of a font it may get slightly skinnier and wider due to the nature of the curves of the font and due to precision errors. I also recommend you print extra small font with high flow - e.g. 150%.

 

 

If you plan to do this kind of font printing like I did - look at the pictures carefully. The text was .1mm thick (very very careful/perfect leveling done by trial and error moving the screws and *not* by using the leveling procedure!). The white part was modeled, sliced and printed as a completely separate part with the bottom layer .3mm thick. This is important: .1mm for text, .3mm for bottom layer of part.

 

Also note that the "J" part in the 3rd picture had only 100% flow on a .31mm nozzle/shell setting (with actual .4mm nozzle) so I had to redo that part with 200% flow to make it look good. These are drink clips so each person knows which cup is their own.

 

[param-mehta 0]

@gr5 those prints look great!! Thanks for the tips. Question- how did you do perfect levelling not using the standard procedure? I would think manually moving the print head along the x and y axes and measuring at various points would be a good way to go? Is the paper method not accurate enough?

 

[gr5 2,172]

Is the paper method not accurate enough?

 

It's not accurate enough. The paper is .1mm thick and if you are putting down .1mm layer for bottom layer you want an accuracty of about .03mm. So you just print the skirt or print anything and the traces laid down should be .4mm wide and .1mm thick. The thickness is difficult to check but the .4mm width part is easy. You can use a ruler, a micrometer or just look at two traces and 2 traces should be twice as wide as one as they will be spaced .4mm apart. Or you can make sure the trace looks to be about 4X wider (.4mm) than it is high (.1mm). It's easier than you might think. And you can do it live *while* it prints. Although I tend to adjust this on every print for a while until I get the leveling perfect. I usually adjust all 3 screws the same amount. But sometimes one side/corner needs to be higher or lower. Just do small adjustments and it will slowly get better each time.