cura 4.6 travel moves

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ive run into an issue that I didn't notice on previous version (though could well have been there) but it is certainly annoying me at the minute.

im not really sure if its a litch or an issues that's going to cause bigger problems in the future, but here goes.

 

im basically having troubles with travel moves on the first layer. in that Cura doesn't seem to want to plan a short travel move but rather speeds from one side of a model to the other.

to go into more detail I have a door model, that as a small square cut out at one end, it starts printing the small cut out and then moving to the outer shell of the main door,  it will print the small cut out and then rather than moving to the edge closest to where it finishes, it wil instead choose to move all the way to the opposite side of the model and start printing the shell.

 

Normally it wouldn't be a problem, but I then I have the problem that it leaves trace material as it moves the hot end. no matter if I have retraction on, any type of combing function on or off doesn't effect it because its only the first laer so technically nothing has printed yet so theres nothing for the printer to "comb" over.

 

which leads me to my second problem in that on the preious version of cura my retraction settings were rather high.....as in retraction length 8 or 9 and speed of 80mms, which is what I found worked best for my printer and slicer settings. but this new version of cura seems to max out at 50mms for retraction speed and will not allow me to slice if my settings are over this, which for my printer setup just isn't enough.

 

so kind of a two in one problem here but im hoping I can get it solved here. the travel move really is baffling me to be honest, im not sure what kind of algorithm is used to determine how it prints but Im hoping there is something simple im over looking, maybe a setting I haven't got highlighted. ive included an image of what I mean. it only does it on the first layer, all subsequent layers it does go to the nearest edge and print without issues. but it does leave a rather unsightly line in the print compared to the mirror image piece that is printed at the same time

 

[nitro2k01 1]

The algorithm prints the all the perimeters before the bottom layer, so it needs to first print the outer and inner perimeter (ie the hole). The outer perimeter happens to end at the far end of the print with the unsightly line, so it needs to travel that long distance to reach the inner perimeter. A way to control this in a hopefully somewhat predictable way is with the Z seam settings. Z seam position should be set to user specified, Z seam value to a corner or edge of your choice. Now rotate the parts so that the hole is facing that corner or edge of the buildplate, so the path from the seam position to the inner perimeter is shortest. "Front" is probably recommended in this case because that's where the purge line ends and so that's where the first perimeter will start. Again though, you may need to fiddle with these settings to get it right.

 

Another possibility is to enable Z hop to lift the hotend during travels and hopefully minimize the leakage of filament onto the bed. 

 

I don't know how the part looks on the other side, but if physically possible, flip the part around so the visible side is printed as the top layer. Then enable the ironing feature, which will smooth out the surface and make it look nice. 

 

I'm also noticing a possible underextrusion issue. I would check the following:

Is the bed levelled correctly?

Does the nozzle diameter setting match the actual nozzle diameter?

You may want to calibrate e-steps. (Search for guides.)

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Hi, could you please provide the project file for this? Do File -> Save and then attach the .3mf to this thread. Thanks.

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5 hours ago, nitro2k01 said:

The algorithm prints the all the perimeters before the bottom layer, so it needs to first print the outer and inner perimeter (ie the hole). The outer perimeter happens to end at the far end of the print with the unsightly line, so it needs to travel that long distance to reach the inner perimeter. A way to control this in a hopefully somewhat predictable way is with the Z seam settings. Z seam position should be set to user specified, Z seam value to a corner or edge of your choice. Now rotate the parts so that the hole is facing that corner or edge of the buildplate, so the path from the seam position to the inner perimeter is shortest. "Front" is probably recommended in this case because that's where the purge line ends and so that's where the first perimeter will start. Again though, you may need to fiddle with these settings to get it right.

 

Another possibility is to enable Z hop to lift the hotend during travels and hopefully minimize the leakage of filament onto the bed. 

 

I don't know how the part looks on the other side, but if physically possible, flip the part around so the visible side is printed as the top layer. Then enable the ironing feature, which will smooth out the surface and make it look nice. 

 

I'm also noticing a possible underextrusion issue. I would check the following:

Is the bed levelled correctly?

Does the nozzle diameter setting match the actual nozzle diameter?

You may want to calibrate e-steps. (Search for guides.)

Firstly. Thank you for the advice on Z seam that actually did the trick. It was set to "sharpest corner" which I changed to "shortest" and now it just heads to the nearest edge without travelling all the way along the piece

 

I haven't noticed an under extrusion issue myself. The bed seems to be level. But I have been having a slight problem with adhesion so I may go back and have a fiddle with it see id I can't get it a bit more dialed in. Thank you

 

I have been using PLA+ nozzle temp 205 and bed 70. I print on a glass plate too. And im still struggling to get the first layer to stick in places its rather temperamental as it will sometimes stick,  and sometimes there will be a little extra filament that curls up as it starts to print and sticks to the nozzle as it drags along

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After a lot of trial and error. Thought I'd post my solution just in case any one else has the same issues. Turns out all I needed to do was turn combing to infill only. The line was from the fact it wasn't reaction when it moved because I had comb set to ALL so it was combing rather than retracting the first layer. Soon as I turned it to info only it still made that large movement but it retracted so no filament line was drawn