RE: Temperature shrinking compensation
Thank you very much. That will help very much.
RE: Temperature shrinking compensation
Can I ask why you have 2 M92 lines of code?
RE: Temperature shrinking compensation
Ignore the first one, it is commented out with a ";" and was a different test.
RE: Temperature shrinking compensation
The shrinking applies to internal as well as external sizes. As in the internal opening will get larger with shrinking whereas the external size will get smaller. So a shrinkage adjustment is not fixed by just adjusting extrusion multiplier.
I remember my physics teacher asking us what we thought would happen to holes in an object when it contracts. I said what you said. Wrong. He pointed out that the entire object gets smaller in all directions. Think of the perimeter of the hole in isolation, it will get shorter, not larger.
RE: Temperature shrinking compensation
As far as I know, there is no way, other then to use whatever filament your using, print it, and measure the difference as it printed the first time, compared to what you expected and adding that, as a percentage, to your models measurements. As far as I know aside from using an "ecosystem" for example "Stratasys" printers and filament, there is no other way. do you know something I don't?
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Swiss_Cheese
I'm assuming you mean adjust the model measurements in whatever design software you use. There is a problem with that approach for those that also use their designs on a lathe or a mill (or whatever other not-a-3D-printer).
RE: Temperature shrinking compensation
The shrinking applies to internal as well as external sizes. As in the internal opening will get larger with shrinking whereas the external size will get smaller. So a shrinkage adjustment is not fixed by just adjusting extrusion multiplier.
I remember my physics teacher asking us what we thought would happen to holes in an object when it contracts. I said what you said. Wrong. He pointed out that the entire object gets smaller in all directions. Think of the perimeter of the hole in isolation, it will get shorter, not larger.
This is correct, as evidenced by the practice of heating a part up to slip a bearing in.
RE:
Prusa Mk4, Using Polymaker CoPA material. I find that without compensation applied, the Holes in a model get smaller (16.6%) , and the outside dimensions slightly larger (0.35%). The holes are more difficult to fix in post processing than are outside dimensions, and for the current model, having the holes correct is more important than the outside dimensions.
The filaments>advanced tab in Prusa slicer now has the Shrinkage compensation facility. I'm having trouble working out what percentage factor should be entered to cope with both holes and gross dimensions "shrinkage" factors. If I tell it to compensate by -0.35% based on gross dimensions how will this affect holes ?
Oh and I should mention that its really important to have belt tensions correctly adjusted to eliminate other possible causes of incorrect dimensional reproduction. My above comment is AFTER having adjusted belt tensions using the Prusa Belt Tuner App.