GregValiant 1,364
This is a lot like stealing a thread - only different. Your model is a good one for this.
You know I dabble in post processors. I had a couple of prints with large flat supported areas and the finish of the first layer over the support was pretty bad. I though that if I could emulate a dual head printer and put down the interface with a different material that the surface would be much improved.
That turned into "Support Interface Material Change". It is sort of like Pause At Height but instead of pausing at a height or layer, it pauses at the "Support-Interface" on a (user selected) particular layer(s) and you switch to a non-compatible material, and then there is a second pause at the end of the Support-Interface and you change back to the model material. That allows the top layer of the interface to be a "ain't gonna stick too good" surface. For a PETG print, using PLA for the support interface works well and the opposite is also true. The finish of the first layer over the support is outstanding and compares well to what is achieved with a dual extruder printer using PVA for the support.
The Cura set-up needs to be just so. With a "Support Top Distance" of 0.0, and and the Top Interface at 100% density of "Lines", the support comes right off.
What it doesn't work well with is horizontal holes because there are so many pauses required that it's just annoying. For flat surfaces - so far it has been terrific. Yes, I am patting myself on the back.
Below is your project with my changes for both the support, and to be compatible with the post processor. which is also attached. It will go into the Scripts folder in your Configuration Folder. I haven't tested it with OctoPrint.
On this model the "Layer of Interest" is layer 82. Searching the gcode for "Custom" will turn up the inserted commands and you can see what they will do.
There are auto-unload and auto-load options. Both amounts will need to be tuned to your printer (setting to 0 will disable them and you can pull out the filament and replace it by hand).
Purge amounts need to be sufficient to clear the previous material from the hot end and nozzle. I guessed at 40mm for your project but it will need to be tuned for your printer. Insufficient purging can lead to a layer of mixed materials and it will be a weak point.
If you don't want to fool with this then just disregard. I'm looking for a sucker beta tester and your model is a good choice for this.
GV sink_front_clip_04_PETG_SuptIntMatlChange.zip
These are the settings for the script. If you have questions post them here.
This is layer 82 which is the last layer before the roof goes on. The supports have been adjusted.
Edited by GregValiantUpdate to SuptIntMateriallChange.py
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GregValiant 1,364
Increase the "Branch Diameter Angle" to around 20° and make the "Initial Layer Diameter" around 20.
That will give wider bases. The model is short so the trees have to get wide faster(more angle) than they would on a taller model.
Here the brim of the supports and about 12mm in diameter.
This with the default settings. The support brim is only about 8mm in diameter. That's kind of a shaky base.
Enabling Z-hops at about a 0.5 hop height can help as well . One of the reasons the supports get knocked over is when there are pips sticking up and the nozzle whacks them as it travels.
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