brousant

By the way, if I set the shell thickness to 0.8 mm, in the problem area the actual shell thickness remains the same, but now fill-in and top layer appears. But this is not an acceptable solution, it should be possible to choose a thicker shell for overall increased mechanical strength. Best regards Simon

Hi, The problem area is 2mm wide, so 1.2mm shell walls would have overlapped. Apparently the shell thickness is locally reduced to 0.8mm. This leaves a space of 0.4 mm which I think could be filled without a problem. However it isn't. If I move the "hole for top clamp" (see OpenSCAD code below) 0.1 mm, 0.2 mm and 0.3mm to the right, increasing the problem area width to 2.1; 2.2; and 2.3 mm, then the space between the shells does become filled, but with green line, no yellow. If I move the "hole for top clamp" 0.4mm to the right, increasing the problem area width to 2.4 mm, then a bit of yellow fill-in/top appears. If I move the "hole for top clamp" 0.1 or 0.2 mm to the left, reducing the problem area width to 1.9 and 1.8 mm, there is again no fill between the shell walls and no top layer. The width of the skinny area you saw is 1 mm and there the shell wall is further reduced to 0.4 mm, leaving a space of only 0.2 mm. But in this tiny space fill-in and a top layer are present! With a width of the problem area 1.8 mm we have a space of the same 0.2 mm, but in that case no fill-in and top layer... It looks like local reduction of shell thickness and filling/top layer are inconsistently handled and I wonder if this can be qualified as a bug. Below is the OpenSCAD code I used to make this part. difference(){ union (){ // base translate([0,-12,0]) cube ([17,32,3]); // support translate([0,-12,0]) cube ([17,5,5.6]); // pole translate([0,0,0]) difference() { translate([0,0,0]) cube ([13,8,7.2]); //hole for top clamp translate([2,1.5,2.9]) cube ([8,5,8]); } // side guide translate([12,-12,0]) cube ([5,5,10]); translate([12,-12,0]) cube ([5,18,7.2]); // top clamp translate([-20,-2,0]) cube ([12,10,3]); translate([-17.9,1,0]) cube ([7.8,4.8,7.2]); } // recess for pcb break bridges translate([5,-3.5,3]) cube ([4,4,10]); translate([8.5,-8,5.6]) cube ([4,5,10]); // screw hole 5mm translate([10,16.5,-1]) cylinder (h=11.5,r=2.5,$fn=100); } Best regards, Simon

Today, I have been happily printing parts with excellent mechanical strength. However, here is a part where I encountered a similar issue. Despite using correct shell thickness setting now, as in the printed part, in the layer view you can see that the space between the shells (indicated by the black arrow) is left open. The fill is missing in this area as well as the top layer. In the normal view you can see that this area should have been closed. The only changes I made to the "fast" quickprint setting were the shell thickness (which was 1mm as copied from the quickprint settings, doesn't that mean the quickprint settings are incorrect?) and the fill density. If this is again a case of beginner's mistake, I wonder what it is!

Hi, Thanks! I should have noticed the significance of the box being yellow... I also was not aware of the layer view. Anyway the parts I printed so far were acceptably strong for the purpose, with the correct shell thickness it can only get better Best regards, Simon

Hi, I have been using an Ultimaker 2 since a week or two. The primary use is to print special parts for electronics test jigs. The parts do not need to be particularly beautiful but they must be mechanically strong. So I print at normal speed but with increased wall and bottom/top layer thickness settings. Now the problem is that in some areas the printed object is not closed at the top and bottom. Here is a screenshot of Cura with a part that shows this problem (this part was straightforwardly designed in OpenSCAD) In the below image you can see that there is a space between the walls that is not filled in with a bottom and top layer. But maybe the real problem is not the absence of a bottom and top layer, but that the wall thickness is much smaller than it should be. If the wall thickness were 1.5mm as specified, that hole would be closed to begin with, and there would be no need for a separate bottom/top layer! However the measured thickness of the wall is only about 0.8mm. Another problem with this print is that one wall did not fuse together (not only is the wall not fused to the top/bottom layers, but the two layers that make up the wall are not fused to each other). I am printing with the first roll of PLA that came with the Ultimaker 2 and apart from the changes shown in the CURA screenshot I use all standard settings. What is the problem here and how can I fix it or work around it? Thanks in advance Simon