# 3D Printing Question If I have calibrated my X & Y axis perfectly.

3D Printing Question If I have calibrated my X & Y axis perfectly. Meaning when I click move 100mm it moves 100mm. Should it not print a 20mm cube 20mm? I am having the issue where the 3D model is not coming out exactly right it’s about 1mm off. Any thoughts?

Perhaps you are overextruding and your plastic oozes out a bit. Your filament diameter, E calibration, and extrusion factor all play a part in that.

What kind of ‘off’ ?

Under? Some materials shrink when cooling down.

Over? Maybe too much meterial extruded as @Al_Williams mentiones.

imagine your extrusion is 1mm wide. If your extruder moves in a 20mm square, the outside dimensions of the square of plastic it produces will be 21mmx21mm, and the inside dimension 19mmx19mm. your slicing software is supposed to know about this and account for it, so to draw a 20mm square it will produce gcode that moves the print head in a 19.5mm square.

if you are sure your motion is accurate, then the most likely problem is your slicing software not having the right data about your extrusion rate/width.

I was able to get it to work by changing the “Default Extrusion Width” in Slic3r to .85 mm.

If you calibrated you’re X and Y, then you’re off. They should have an exact value in the firmware as there is nothing to calibrate for. Usually 80.

@John_Ridley I have been working on calculating instead of calibrating the xyz were easy and are coming out correctly. However when I go to calculate my e steps it’s pretty wacky. Using the following , Calculate E_steps = motor_steps_per_rev * driver_microstep * big_gear_teeth / small_gear_teeth / PI / hob_effective_diameter

200 * 16 * 39 / 11 / 3.14159 / 6.89 = 524

With that setting it ran out almost 213mm of filament.
So using the following,
calculate new_e_steps = e_steps * 100mm / measured_distance
524 * 100 / 213 = 246

I checked the jumpers and there set for 1/16 microstepping and the sticker on the motors said angle of 1.8 which is supposed to = 200 steps. 246 seems to work however I am not sure why there so far off.

If you slice with 1.75 mm filament and then print with 3mm you would be in the ballpark of that. I have experienced something similar when I had the idler tightened to hard and I clicked twice and it suddenly manage to turn. I suggest you try recalibrate E steps as they are likely off. Easy to se if you print some solid layers and there is space between the extrusion.

Everything is now working perfectly. I have never seen such fine looking prints. Thanks everyone for your help.