3dmaker4u

You said you did some different temp/speed tests. However, if you look to the bottom of the speed test object, you can see that the surface is rough for 3 (and 4 , but less). So at 3 cubic mm per second you have a too... higher temperature. It's higher because as you increase the speed the phenomenon disappears (if it should have been lower, it should have degraded with increasing the speed. Now, in your test cube, 50 mm/s, at 0.1 mm, means 50*0.4*0.1=2 cubic mm per second. At this speed the temperature is much too higher and the surface would look like it is under-extruded, while it is actually just smashed hot plastic.

Aha! Wow, but this means the firmware should be aware of the filament diameter, which is basically a characteristic of the machine, but does not yet have the required constancy over the entire range of manufacturers. Anyway, then indeed the extrusion is correct in code.

I also made some calculations out of the code... If I assume that the filament diameter is 3 mm, then I get 0.799 mm2 for the sectional area of the extrusion. Great! However, if the filament is 2.85 mm, then I get only 0.721 mm2, which is 10% less, and looks like under extrusion For the outer wall, the area is 0,765 mm2, assuming 2.85 mm diameter, so considerably less under extrusion, hence almost not visible. So, which is actually the diameter of the filament in use? LE > there is a 0.1 factor that I don't get. The area of a 0.4 mm by 0.2 mm extrusion in 0.08 mm2. I assumed all G parameters are in mm, aren't they?

Apart from the issue in the first phrase, which appear to be related to a Z axis issue, there is lots of under-extrusion. You also mentioned the knurled piece chewing the filament. Until guys more experienced with UM2 will come up, here are some "generic" potential causes: - extruder idler pressure to high (there is an adjustment screw and a white pointer on the extruder black case on the back side of the printer) - temperature to low foor the speed and material you're using, making hard for the extruder to push the filament through the nozzle - start of a clog in the nozzle - deformation of the teflon piece on the cold side of the hotend You do not mention any "clicking" noise, but you have not notice it. If it is present, it indicates the extruder motor is skipping steps, which is a feature aimed to preventing filament from being chewed. Otherwise, it means the current setting for the extruder motor is too high. Basically, you have to track all the way up and down that the filament is carried. Somewhere and for some reason it has a hard time to advance

Looks to me it's a Z zeroing issue. Don't know how UM is homing Z, but I assume it does faster closing to the bed, then returning for a while and then slower coming back to zero. During printing multiple pieces, one at a time, I don't know if it does the same each time. If not, and using instead a straight positioning command, then it might not obtain the same "zero". Just try printing all at once, so that each layer will be printed for all pieces before jumping to the next, and I can bet there will be no problem. If this is the case, then you just have to investigate if there is an abnormal backlash in Z mechanics.

If quality means how they look, I would say both. It is rather a matter of knowing how to get "the best" out of your printer. Obviously, the printer should be equipped to support the material (particularly bed adhesion and temperatures might be of concern). If quality refers to mechanical characteristics, I would say both, but depends on the application

I can get 1 hour of printing for something like 40 mm/s at 10% infill, 2 layers raft and the rest of the specified settings (sliced with slic3r, but I don't thing it matters to much). So, was the speed on Zortrax 70 mm/s as for UM, or not? What about speed on Up!+2?

@Alexiej Have you used the same (similar) settings across all printers? I suppose you didn't used the same slicer, but I'm just curious how long did it take the print on UM2 compared to Zortrax. Frankly speaking, I cannot see how can a printer reproduce such details with good quality on a 30 x30 x 40 mm part running at 70 mm/s. Only maybe if the acceleration and jerk is set to so lower values that it actually runs at 20 mm/s or so.

Could be that the steppers and/or the drivers get hot and start loosing steps and/or get locked? Though I could not expect this to happen after 10 layers or so, as in the picture, but could happen if the current is also high.

The only way I know to have horizontal cylinders is... support and post-processing. Support could be created by design or using the slicer features. Then carefully filing would do the job. A trick would be to "invent" something that requires to be present there and justifies the peculiar aspect, don't know, a valve or something

That kind of "banding" looks to me rather a consequence of the pretty high speed you are printing at. I can bet that if you are patient to try at 20-30 mm/s it will disappear. It is also that artifacts are more visible on white (with "adequate" lighting) than on colored material.

Now, seeing the extruder picture above, I'm wondering if a full rotation of the motor, for the given printing speed and the circular pitch of the knurled bolt would be.... synchronous with the red pattern. This might be another possible cause for the under-extrusion (this time really that).

Just curious: when you say "layer width", do you mean "layer height"?

Awesome pattern I don't know if the top-left corner of the print corresponds to the front-right side of the printer where, if I'm not wrong, you found an issue on the mechanism (post #93), but could be related to it. The pattern remain the same, no matter the printing direction. And repeats regularly, apparently on both X and Y (looking like stationary waves). Given the particularities of UM, using parts of one axis mechanism for the other axis as well, this may imply that an issue on one part, may actually impact on the other axis movement as well. By now, I can understand that, if something happens periodically on, let's say X, it will also periodically affect Y and that's how a "square" pattern appears. The fact that the impact is more adverse should be related to the faulty corner. Logically should be the same, but I suspect is the opposite, which confuses me a bit). The periodicity indicates that the the effect is given by... rotation. Now, the frequency of the pattern. Looks like 3-4 cm or so This is pretty close to what I can estimate is the diametral pitch of the pulley. Why "under-extrusion"? Since there is no reason to question the extruder feed rate, an alternative would be that the axis is travelling... faster and then is slowing down and repeat. This looks again like a consequence of something similar to the belt "climbing" on the pulley side hence "riding" a larger diameter. I think the logic by now works with the given facts. However, why not on the first layer, this is something that does not fit yet my mind

What if actually the code generated by Cura is wrong?

I would suggest printing a larger cube aligned with the bed edges and with the infill at 0 degree. The idea is to "separate" X from Y and see where the issue appear, on a wider perspectiive.

I like very much the picture since it clearly shows patterns of artifacts, depending on "holes structure". Now, thinking about what George wrote above, that's clear that the actual print direction, meaning for me the direction the head is moving to lay down the extrusion, is in our case from left to right Then, going from bottom to top, one can see very clear the effect of the phenomenon that George explained particularly on the left edge of the first part of the first hole to the right And is not so bad yet. As long as another hole enters the picture, the situation is getting worse. With 2 is still reasonable, but when it gets to 3, ough! Here is where mainly lack of fan let things go badly. Apparently speed has not so much a contribution, because in a few mm of acceleration you will not get to a terrible speed, but that's enough to "ring". This is visible where the holes are far apart, elsewhere heat is partially... melting the evidence

Well, so "printing direction" means... "Z direction". I'm not sure why did you make this choice of positioning the part (looks like part of an enclosure with ventilation holes, but is just an impression). The point here is that the piece seems to be longer in the "print direction", which makes it somehow fragile. This being said, the area between the holes is perhaps 5 mm or so. 50 mm/s is too much for such short perimeters. At the corners, the nozzle will drag the extrusion a bit in the new direction so that it will not be laid straight. Additional to the advice in the post above, just try to increase fan speed.

Just to raise the ambition level... I "signed", sliced and printed one "standard sized" gear-bearing in a bit longer than one hour and... give it to a friend. You have to believe me until I'll make another one, smaller, nicer and in shorter time And I did it with one of , not an UM

If you don't have the scan, than you have the option to "sculpt" the bare sole. You need anyway some information about the foot, like a mold or even pictures. I don't know the current practices, but I would expect most probably a mold to be used. This could be easily used to determine a "point cloud" with repeated measurements following a grid. This could be used to generate a rough foot model that could be further sculpted. While may sound very rudimentary, could be actually very cheap and fast

Did you check the actual height of the printed layers? It looks to me that, for whatever reason, the layer height varies and so the lines get thinner/thicker hence... taller/shorter. Correlated with the peculiar noise, this may indicate a mechanical problem, somehow related to Z axis. LE If not uniform in layer, then a X-Y assembly issue still exists. Once a mechanical problem has been already identified, and since s..t never happens only once, I would suspect a bed geometry of X-Y assembly.

Yes. Not at all. Create/import the 'shoe' or just the raw sole, then import the foot, position (rotate/translate), you may need to scale the shoe/sole, and finally select both and make a Boolean difference (order of selection counts). That's all.

Nice idea and pretty good implementation Good luck!

Meshmixer has good sculpting tools, in addition to transformation, logical operations, etc. Since you'll have scan data as input, the analysis capabilities (inspector) will also be valuable. You can find some tutorials on YT to start with. I can agree that the interface might appear complicated, but it is not so hard at all. Meshlab could be useful for many things, but I doubt you will like it. I once used InStep to convert STL to STEP, but the "free" mode is limited to 3000 faces, My advice is to give Meshmixer a try.

The blobs appear in the label region. It can be easily observed that at the bottom, and even between the two words, the corners look almost perfect. If the printer has to accelerate/decelerate repeatedly to do all the small details for the letters, the melted plastic in the nozzle will have a very hard time, and will cease here and there. It's no clear pattern, since the words do not have any obvious repeated pattern. You may want to slow down, at least the perimeters, until you are satisfied with the quality. If you also want decent time, use 2-3 perimeters, and print the infill faster to compensate, but allowing enough time for the pressure in the nozzle to relax, before starting the outer perimeter. Decreasing the temperature may also help, since the melted plastic will be less fluid.