Printer Model: Ratrig VCore31
MCU / Printerboard: Octopus Pro klippy.log → Not necessary, think
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Describe your issue:
Hi,
I need your help to interpret the results of the PRESSURE IN ADVANCE test.
I am printing a model from 3D Labprint, with PLA LW. It is a material that, as you know, expands with temperature to weigh less. And with the default configuration I have a lot of stringing, and the manufacturer’s recommendations recommend not placing retraction. So before continuing to print I have followed the guide to adjust the value of Pressure in Advance. This guide:
I have printed the test, but I am not able to interpret what height is the ideal, I see them all the same, perhaps it is because of the material… It was for you to tell me what the height is
It must be said that for the test I used some slightly particular values, I don’t know if they had an influence. For a temperature of 222/55 (where the maximum expansion in previous tests I have achieved), I have used an extrusion factor of 40%…
Another option that I am considering is to repeat the test with PLA (normal)…
I am attaching photos of the piece printed in the test, to see if you can recommend a height, because I am not able to distinguish it.
I am wondering where this holes come from? Did you ever printed a “propper” box with this material (no holes, smooth wall)? I would not recommend to start optimization of something that looks like this…
AFAIK this is somewhat wanted: The LW material will start expanding and creating some sort of foam to save weight. This process depends on the printing temperature. The hotter you print, the more it will expand.
Basically it is quite nice, since you could print your walls / bottom / top at lower temp (no / less expansion) to have a high rigidity while using higher temperature for infill to save weight.
I see. Shouldn’t one start with a heat tower instead? I agree with you 100% that PA will not solve this issue. What you would need is a quick change in temperature shortly before the edge is “in sight”. And this is just impossible with this hardware.
I do not know if “interesting” is the right term. How about “madness”? If you want to save weight, I’d prefer to fill in nothing. If you need additional features like “more stiffness”, there are very good solutions (infill types) available for this. I do not know, if such foam is the right approach… But you learn new things every day…
Not out of the box AFAIK. A friend who is deep into building RC planes is modifying his GCODE more or less manually to achieve this. To get this right and to compensate for the different expansion factors between walls and infill, he has invested an insane amount of testing and tuning.
Hey, perhaps the printed results a right because of the strong expanding material. In the corner the nozzle is longer because of the direction change and because of your strong expanding material the results are also stronger than with “normal” material. Perhaps you need much higher pressure advance values.
If you want to save weight, I’d prefer to fill in nothing. If you need additional features like “more stiffness”, there are very good solutions (infill types) available for this. I do not know, if such foam is the right approach… But you learn new things every day…