Dual extruder, collisions between support and ooze shield
Posted: Sun Mar 10, 2019 10:47 am
I am printing PLA on T0 and PVA on T1. One each layer, it lays down the PLA main structure before the PVA supports. There are many situations where I see the PVA line crossing a previously-deposited PLA line on the same layer, or even crossing other PVA lines on the same layer. I don't see any interruption in the later line....the Gcode previewer shows it as a single line laid right across the pre-existing line. I would think that would be undesirable, and lead to a bump in the second line, and perhaps some disruption of the first line.
For example, in the attached Gcode, line 548 is PLA at 0.18mm (first layer). Line 1585 is PVA crossing this also at 0.18mm. The Gcode viewer plots it as an intersection between the lines. In this case, the PLA is part of the ooze shield, and the PVA support is drawn with large "extra inflation distance" to show this problem. But I run into this problem unintentionally also, for example if using Waterfall ooze shield on a complex shape. Note that in this example the PVA support (later line) is crossing both the PLA and the PVA of the ooze shield (laid down earlier).
I can avoid this by making the ooze shield far away (for example Waterfall), and/or I can make sure "extra inflation distance" is zero, so that the support structure is smaller. Generally there is a way to avoid this by adjusting things. But I am unsure which of the following is true:
1. This is an actual bug (?)
2. This is just how it works, and I am supposed to preview the Gcode, look for such situations, and avoid them by adjusting positions of support vs main lines. (?)
3. This is just how it works, and it doesn't cause any physical problem, so I should just ignore it (?)
For example, in the attached Gcode, line 548 is PLA at 0.18mm (first layer). Line 1585 is PVA crossing this also at 0.18mm. The Gcode viewer plots it as an intersection between the lines. In this case, the PLA is part of the ooze shield, and the PVA support is drawn with large "extra inflation distance" to show this problem. But I run into this problem unintentionally also, for example if using Waterfall ooze shield on a complex shape. Note that in this example the PVA support (later line) is crossing both the PLA and the PVA of the ooze shield (laid down earlier).
I can avoid this by making the ooze shield far away (for example Waterfall), and/or I can make sure "extra inflation distance" is zero, so that the support structure is smaller. Generally there is a way to avoid this by adjusting things. But I am unsure which of the following is true:
1. This is an actual bug (?)
2. This is just how it works, and I am supposed to preview the Gcode, look for such situations, and avoid them by adjusting positions of support vs main lines. (?)
3. This is just how it works, and it doesn't cause any physical problem, so I should just ignore it (?)