Calibration circle and hollow top 20mm box

thingiverse

Here are two files. One is meant to be printed at .3 layer height and the other .2 layer height. Pick your preferred layer height and print that one. The way this is designed is one half the circle is one layer, the other half is two layers. The box on top is 20mm tall from the bed with walls .8 thick. Calibrate your esteps by marking 110mm above the extruder, heat nozzle and extrude 100mm of filament. Measure how much distance is left from of the 110mm. Change ESTEPS so that 100mm is 100mm of filament movement. If you extruded 105mm and your esteps were 80 (80*100/105)=new estep value. Now, slice this file so that you are using 100% outer and inner wall flow and 90% infill, 90% top skin flow. Print the part and as the layers are laying down look for a smooth top and that the lines are joined together. Let the print finish and try and pull apart the layers in the 1/2 circle that is one layer. If they are holding together and relatively flat your top layer/infill is close. Now measure the wall thickness of the cube in many places. It should be .8mm. If it is only .75mm thick change the flow to make .8. Same formula as above: 100*.8/.75=new wall flow. Measure the height of the cube form the first layer (after your walls are .8 thick). If it's 19.85 then the Z offset needs to be raised .15mm. After this you may have issues with 1st layer adhesion. This is because you may have set your Z offset with paper under and it has your Z lower than it should be. Increase your first layer flow to 105% and see if the 1st layer sticks and the 1st layer has a uniform dimension the same as the rest of the cube. If it's narrow at the base and widens you need more flow. If you have elephants foot, you need less 1st layer flow. This test should get your top layers smooth enough to get a reflection in the top layer. This test is intended to get your flow close so that you can further make test prints with less changes to flow and concentrate on retraction, temp and fan speed.