Topic: Material Flow Rate Calibration in Cura Using a Powder Scale
I've seen a number of different methods for calibrating the flow rate for filament, such as using calipers to measure filament, etc. I don't know if this is the best section to post this, but it seemed close enough, since it has to do with extrusion. Anyhow, I worked out a method that seems to work well that I thought I would share.
1. At the bottom of the "basic" menu settings in Cura, there's a box for filament diameter and flow rate. For diameter, enter whatever diameter filament you're using, 1.75 or 3.
2. Build a STL for a box with a volume of 1 cubic centimeter. For example, 1 cm x 1 cm x 1 cm, or 1 cm x 2 cm x .5 cm, etc. That will be your calibration file.
3. You can get digital scales for measuring small amounts of weight starting around $25. They're commonly sold for measuring powder for reloading ammunition, scientific stuff, etc. I calculated the weight of 1 cubic centimeter of ABS at 16.1 grains. That number can be converted to whatever unit of measure you prefer, ounces, miligrams, etc.
4. Print the 1 cm calibration file and weigh it.
5. Divide 16.1 grains by the result, which will give you the percent value to enter in the "Flow" box in Cura. For example, if the weight of the calibration model is 16.5 grains, divide 16.1 by 16.5 to get .9757, or 97.6%.
Manufacturing tolerances on fliament diameter can vary a bit. I've been using this method when I load a new spool of filament and it seems to give good results. It only takes a few minutes to print a 1 cm box and the method is reasonably idiot proof, without a whole lot of fooling around. When I print a second box and weigh it after doing the above, the margin of error in the 16.1 target weight is tiny, usually within 1/10th of a grain.