# Prusa XI3 Extruder Calibration

I have done the calibration for the x, y, and z axis and everything works fine there. However when I went to do the calibration for extruder things got a little weird. The original number programmed on the board for the step per mm was 98 When I did my first measurements I used 120mm as the mark on the filament then extruded 100mm then remeasured the mark it was 37.66. Then by using the new_e_steps = old_e_steps * (100/(120-distance). I would use the new number and upload it to the printer which was 119.0187. After that I took another measurement, the new measurement was 61.27mm after marking 120mm then extruding 100mm of filament. Using the formula it came out to be 202.6540. Then the new measurement was some where around 80 some MM. It seams that the more I do the calibration the less accurate it gets. What am I doing wrong here?Triffid Hunters Calibration is the guide I have been using and this link is to the specifications to the printer HE3D Prusa XI3.

• It seems like you made a calculation error, but to check what we need to know more. What value did you enter for distance in that equation, and in which direction was it off by 10mm? How much filament did you ask to extrude, and how much was actually extruded? What did you calculate as new esteps, and what was the old value? – Tom van der Zanden Mar 26 '16 at 15:40
• I updated the question. – Dakota Miller Mar 26 '16 at 16:26
• This hasn't made it much easier, I'm afraid. Perhaps you should do the calibration once again, then update your post with the exact steps you did, what values you measured, and how you did the calculation. – Tom van der Zanden Mar 26 '16 at 16:39
• Sorry I kinda just shoved the information in there let me edit it real quick. – Dakota Miller Mar 26 '16 at 16:42
• Ok I Edited it again and should make more sense now. – Dakota Miller Mar 26 '16 at 16:47

It is really strange that although you increased the steps per mm, the amount extruded was less. I can think of two possible explanations:

• You are extruding too quickly, at a rate at which the extruder can't keep up melting the filament fast enough, causing the filament to slip or the extruder to miss steps: try lowering the feedrate (a feedrate like 100mm/min is typical for 1.75mm filament) and make sure that the temperature is appropriate to your filament.

• You are in absolute coordinate mode, and when you try to extrude 100mm it actually extrudes a different amount (based on the previous "position" of the extruder). Enter relative coordinate mode using G91.

• I am using abs with an extruder temp of 210. I found that my feedrate was set to 1 I remember changing this when I first got the printer so i changed it back to 2. But the way you are describing it should be like 1.6 something right? – Dakota Miller Mar 26 '16 at 20:12
• The "1" value is not your feedrate. That probably is your extrusion multiplier. Don't mess with that (leave it a 1) until you get your esteps approximately correct. – Tom van der Zanden Mar 26 '16 at 20:33
• When i go to configuration then down to feedrate on the lcd it says max:1 home:2 – Dakota Miller Mar 26 '16 at 20:52
• The feedrate that I'm referring to is simply the feedrate you set with a G-code command, e.g. G0 E100 F100. – Tom van der Zanden Mar 26 '16 at 21:11
• Oh ok i think i understand what im doing wrong then. I have been using the lcd to extrude 100mm and not the software on the pc. Could that be it? – Dakota Miller Mar 26 '16 at 21:37

I understand you marked at 120mm then tried to extrude 100mm and measured 37.66mm remaining. Take the 120mm - 37.66mm (remaining)= 82.34mm (that was extruded (so you were 17.66mm short of your 100mm).

The formula I use is [New Setting=(Wanted Distance X old setting)/ Actual Distance].

So [New Setting = (100 x Old Setting)/82.34.]

Hope this helps