Dimensional Accuracy Adjustments
I am using the SL1 for prints that are mostly engineering in type and I would like exact dimensions wherever possible, especially as these are sometimes pretty precise parts. I have made a simple 25 mm calibration square with a solid base and 2 mm thick walls and have been experimenting with the resulting size of the part after printing and again after curing. I can see consistent shrinkage after curing.
I have been able to get the wall thickness of the test square down to an error of +/- 0.01 mm by reducing the cure time to 5 seconds per layer, but I still have a 0.20 error in the overall size of the part. I am starting to wonder if I should be making the adjustment somewhere else and not changing the cure time. I don't have any issues so far with a 5 second cure time; the material seems to be fully hard. I Am using Prusa tough cyan.
Has anyone else done this type of check, and if so, how did the error in the size of the parts get resolved?
RE: Dimensional Accuracy Adjustments
I think I have this figured out.
Overall part dimensions are controlled with the variable "Correction for Expansion". For the cyan tough resin, I get the best overall dimensional results with a correction for expansion value of 0.99 and a cure time of 5.5 seconds. This gives me a test part that is within +/- 0.04 mm overall with wall thickness accuracy of +/- 0.02 mm. Strength seems the same with the reduced cure time based on the limited testing I have done.