Switching processes adds entire bridge layer

[worldspawn]

I've got a two process print. Both processes are 0.1mm. The first process stops printing at 0.11mm and the second starts at 0.10mm. I have this because my printer is crap and i need a bunch of different settings to get a good first layer.

What i found though is the second layer (the first layer of the second process) is printed entirely as a bridge. Can something be done to prevent this?

First layer

Second layer

Third layer

[S3D-Jake]

Can you attach your factory file?

[Großschmackhaft]

Do you need bridging? If not, set the Treshold Area to 99999.

[dkightley]

Without the factory file, we're all totally guessing...including me, but here goes.

I think the model is not completely flat on the bottom...and consequently there may be a very very small gap below most of the part and the bed.

The first layer ....the only layer in the first profile, when generated by the slicer, just so happens to identify that part exists over the whole area...and the first layer...a very thick layer...is printed.

The second layer, the first actual layer of the second profile, but the second layer of the theoretical print, is a thin layer, and the slicer, because there is a gap underneath the part, does not identify that any plastic has been laid down by layer 1..if it had been printed....and therefore invokes the bridging. With the bridging set to include perimeters, the whole of the "second layer" of the print is bridging.

Of course....as I've said, this could all be total buncum! Without the factory file to tell the absolute truth about the starting position, we're all guessing....aren't we?

I think the first thing the original poster should do is to resolve the issue he has with the first layer printing that makes him think he needs to have a separate process for the first layer. Resolve that problem, and he'll then find he's not getting a complete first layer with this print....and the resolution then may be to lower the part down so all the bottom faces hits the bed!

[parallyze]

Can something be done to prevent this?

Yes, entering reasonable numbers into the processes does prevent this. So if you want a 0.1mm layer, don't stop the process
at 0.11mm and start the next one at 0.10mm again...

I tried to recreate this, factory file attached.

Process1, 0.1mm layer height, stops at 0.11mm
Process2, 0.1mm layer height, starts at 0.10mm

Checked this out of curiousity. I would have expected a warning that two processes interfere with each other. Seems S3D calculates
overlapping based on layer height, not exactly what's been entered in start/stop. Maybe those values should be checked too and
a warning displayed if they overlap (stop 0.11, next one start at 0.1)...

Oh, not only is the second layer completely bridged, it's also adding a 2nd layer for the skirt which is set to "1 layer".... and it doesn't
set the fan to layer 2 speed here, M106 is missing. Solid layer angles are wrong, looks like process2 ignoring some settings of p1 in this case.

Code: Select all

; process Process2
; layer 2, Z = 0.200
; feature skirt
G1 Z0.200 F480
G1 X115.118 Y90.750 F12000

Entering normal start/stop positions (0.1mm in both cases) avoids this.

I have this because my printer is crap and i need a bunch of different settings to get a good first layer.

...if that printer is "crap", how can creating a gap/overlap of 0.01mm between processes improve results?

I think the first thing the original poster should do is to resolve the issue he has with the first layer printing that makes him think he needs to have a separate process for the first layer. Resolve that problem...

This.