Delta printer calibration (size of the print) step per mm

thingiverse

Hello, I'd like to share how I calibrated my delta printer. The problem I had was with the size of my prints - they weren't accurate (100mm square gave me 102.xxmm*101.xxmm*99.xxmm*100.xxmm). I'm not saying this is the best way to fix it, but I'll share how I fixed it myself. With this method, the biggest difference between the lengths of the square sides was 0.2mm/0.3mm - maybe I can achieve better results, but it's fine for me. So, I calibrated it in the firmware (Marlin) with this line: #define DEFAULT_AXIS_STEPS_PER_UNIT {80, 80, 80, 100} (x,y,z,e) What we want to change is the x,y,z value - depending on how you assembled your printer, the order may be different. In my case, changing the value one at a time will change the speed of the step motor movement and help me find the right order for my printer. If I lower my hotend height, I'll notice that one of the step motors moves differently - so it could be (x,y,z,e) / (z,x,y,e) / (y,z,x,e) etc. Okay, to calibrate your delta printer... What you need to do is print my calibration test, which should be right in front of the 3 towers. The three rods should measure 30mm by 3mm. If not, follow these steps: 1. Print and measure the length and tower associated with each rod - for example: (Tower X: 31 Y:29 Z:30) 2. You'll need to do some math... take the length it was supposed to be "30" multiplied by the current step per mm value "80" (30*80=2400) - then divide it by the measurement of the rod. So for Tower X, it should be (30*80)/31 = 77.42. For Tower Y: (30*80)/29 = 82.76. For Tower Z: (30*80)/30 = 80. 3. Enter this value in Arduino so it will be: #define DEFAULT_AXIS_STEPS_PER_UNIT {77.42, 82.76, 80, 100} (x,y,z,e) 4. At this point, you'll need to adjust your endstop and do Z height calibration (paper test). 5. Print again... what we want is for the sides to be as close to the same length as possible - even if they don't measure exactly 30mm, that's not important since we can resize with DELTA_DIAGONAL_ROD. 6. If the sides are the same or close enough to be the same length, you'll only need to resize the print dimensions with delta_diagonal_rod... if not, redo the steps. Is this tutorial clear enough? What can I change or add to make it better?