For last two weeks I have been struggling with flow rate adjustments. I'm using an UM2, colorFabb XT 1.75mm and Slic3r. Before printing a test cube I made flow rate adjustments using the "Perimeter test" (printed a hallow cube with 1 layer thin perimeter line). I then compared the desired value of the perimeter's width with the value from the g-code and adjusted the flow rate. I repeated this procedure until I got exactly the thickness I needed. After that, I printed a 15x15x15 mm cube and observed under extrusion on top layer. Also, the dimensions of the cube in the x-y plane were smaller than expected (0.4mm shorter than they should be). I have done this a few times now, and still get the same result. :/ Furthermore, I was unable to adjust width by dividing the desired value of the width of the perimeter by a real value, I got slightly smaller extrusion multiplier (One I got by division is 0.9 , but 9.5 relates to desired width). Do you have some suggestion guys?
I'll try to explain the calibration method I have used.
- I have made in Solidwork 15x15x15 mm cube.
- The cube was imported into Slic3r, where I have set the infill to 0% and number of sides shells equal to 1 and number of top and bottom shells equal to 0 (It gave me one layer thin wall in shape of cube).
- I printed it out and measured the width using caliper and compared with the perimeter's width from g-code.
- I have got something about 0.7, but the extrusion width in g-code is 0.65, so I changed extrusion multiplier by 0.65/0.7 = 0.93 (what is not actually true, because I got correct value on 0.95 only)
- I have repeated the procedure for many times, and always got wrong dimensions and under extrusion. There is the video about method I just have explained: https://www.youtube.com/watch?v=cnjE5udkNEA