Printing walls in one shot

[fma 2]

Cura 2.3.1 is really nice. But, there is still one thing which annoy me... A lot!

When I ask for 2 perimeters, why does not Cura print the 2 perimeters of each wall in one shot, instead of printing the first perimeter of each wall, then coming back to print the second perimiters? Is there a good reason to do that?

First, it takes more time. Well, not that much, but...

Second, and most important: it always mess up tiny holes of the first layer. Always! First perimeter of tiny holes don't close well, and when Cura move away at travel speed, it tears of the perimeter...

So, please, print all perimeters of a wall before printing next one, at least on the first layer !

Then, Cura will be the best slicer ever ;o)

Thanks.

[fma 2]

I'm wondering: did you address this problem¹ in Cura 2.5.0-BETA?

Thanks,

¹ yes, this is really a problem! It messes up very small holes on first layer, and it also gives a much lower adhesion between walls, as the filament has time to cool down.

[bagel-orb 61]

The reason is that with bowden systems it is important to keep the flow of the nozzle constant. The moment you switch from printing the inner wall (at a higher speed, so higher flow) to the outer wall, you get a tiny bit of overextrusion.

In order to minimize that defect we first print all inner walls and then all outer walls (or vice versa, depending on settings)

Also it's not that simple to implement.

I've just made a small fix which makes the outer wall print first when you are using a brim: https://github.com/Ultimaker/CuraEngine/pull/486

[fma 2]

The best solution would be to have a switch. So, people without bowden would get a decent first layer, and stronger parts, and people with bowden, could also get rid of this problem (and if there is really a problem of over-extrusion, the simple solution is to print all walls at the same speed).

In fact, I often see a problem of under-extrusion, when the head moves from perimeters to perimeters without retracting: there is oozing, and there is no more enough pressure to start the next wall of the next perimeter...

One could say that there are more and more params; I agree, but some are really not that important: who is going to fine tune accell/jerk on support or skirt/brim?

Please, target quality first, not speed... Most of use are hobbyists, and time is not an issue.