One thing that is abundantly clear after my 10 day RepRap U.S. tour is that the 3D printing problem involves a large number of interdependent variables. There is no obvious simple solution, at least not one that is obvious to me at this early stage.
Variables like filament plasticity and makeup, filament diameter, a whole raft of different temperatures, hot end characteristics and geometry, slicer algorithms, bed flatness (and leveling), half a dozen different travel speeds, as well as the target part geometry, can all play a major role in the success or failure of any given print.
I was surprised to find that things I had mistakenly taken for granted, like 3 mm filament being 3 mm, turned out to be totally false. Some suppliers provide 2.8 mm filament labeled as 3 mm, while others supply 3 mm. Of course the quoted diameter tolerances can vary widely from actual measured dimensions, often for the same continuous roll of filament.
Even the same filament, from the same manufacturer, can frequently have substantially different printing characteristics depending on the filament color. With PLA, the plastic’s hydroscopic nature also throws in some additional variability.
There is a clear need for a measured, well documented, scientific approach. I plan to institute a rigorous system of measurement, logging, and analyzing results for every print. And to run a series of test parts printed under the same conditions, varying only one variable at a time. Although I haven’t decided on the exact test parts yet, a good example would be to print a 20mm x 20mm x 10 mm block multiple times, incrementally varying hot end temperatures, or travel speeds, or other variables.
Ideally, I want to run multivariate analysis on the total system to develop an empirical model so that I can quickly make first approximations of high-probability settings for new parts. It won’t be perfect, but hopefully it will improve my success ratio and keep me from wasting considerable time with failed prints.
- Shrinking the Design Process Using 3D Printing/RepRap
- Learning From Other People’s Failures
- Printing More Than Plastic
- First Practical 3D Printing Project
- 3D Printing a Hobby Lathe(Video)