in the last two years I’ve help lot of people to fine tune their GEEETech i3 series printer, and lot of time the solution, solved the “normal issues”, was the same… better calibration!
Each single time I give to people ask my help always the same identical instruction in order to do a better calibration, so now I’ve decided to directly share stl I normally use during calibration and write down instruction!
In this kit you’ll find:
- Regular 100x100, and 100x100x100, brackets useful to calculate the exact value of Marlin’s STEPS_PER_UNIT define for your printer
- Standard 20x20x10x1 calibration parallelepiped useful to calculate right value for Slic3R Extrusion Multiplier
- The Excel spreadsheet with the automation of all calculations for STEPS_PER_UNIT and Extrusion Multiplier Calibration
IF YOU “FALL IN LOVE” OF ONE OF MY DESIGNS AND TRICS, PLEASE, REMEMBER THAT IT TAKE TIME TO BE CREATED, DESIGNED AND SHARED… SO “MAYBE” YOU CAN USE THE “TIP DESIGNED” BUTTON ON MY PROFILE!
Not all People that use Slic3R know that inside can find lot of parameters that can deeply impact the quality of printed result, you can found all possible Slic3R calibrations in Alexrj Calibration of Slic3r page (https://github.com/alexrj/Slic3r/wiki/Calibration-of-Slic3r)...
… for me one of main “key success factor” to have good printout is have the slicer correctly informed about filament you’ll use.
That not just means put the right filament diameter, also correctly measured alon one or two meter, because just the diameter do not inform the slicer about the density of material and how the printer work with this material… to give this information to the slicer you must correctly fill the EXTRUSION MULTIPLIER field you can found on FILAMENT SETTIN TAB:
In order to calibrate this parameter I use the file 20x20x10_1.stl…
…and the tab EXTRUSION MULTIPLIER you can found on Excel Calibration Calculations.xlsx
When I receive a brand new spoon, or when my spoon are “little old”, I do this calibration…
… and I start with a first print with 1 in Extrusion Multiplier field:
Then I'll do my first printout I will obtain a sample like this:
With this print out I will use my digital caliper in order to measure how are real thin the sides, and I try to pic just few layer:
and I put this measure in this cells of my spreadsheet:
For each sides of my object I get THREE different measure in order to fill all cells of my spreadsheet:
When all 9 measures are in their respect cell I use the embedded formula:
The fulfill the Slic3r field:
(don’tever forget to save the change inside Slic3r)
With this updated Slic3r profile I’ll redo the print, and during my printer work I reset the excel and put the new Extrusion Multiplier I’ve just measure in the left cell, so next time my calculation will start from this value:
When I’ve get a new sample from my printer I restart t same measurements:
I re-fill all measurement cells of my spreadsheet and I get a new value to use in Slic3r:
And I’ll redo the same sequence till I’m happy with results from my caliper measurement!
Also when your printer is perfectly tuned you must look for the perfect temperature for your filament…
…and not any time the producer suggested temperature is the correct one for your printer!
To find the correct temperature I use the Temp_Tower.stl:
First of all I do a normal slice with 225° starting temperature:
Then I use the Repetier-Host “Editor G-Code”:
And with it I look for the G-Code command for Z 5mm, G1 Z5:
There I’ll add a row to bring down Hotend temperature to 220°, M104 S220:
Then I’ll look for Z10 and I’ll add the row for temperature 215°:
I’ll repeat this approach 5mm by 5mm shifting down Hotend temperature 5° each 5mm till I’ll get 175° at Z50:
With this modified G-Code file I’ll do my print in order to obtain my test samples:
With the printer tower is very easy see the best temperature, in this example will be 180°:
So for this specific filament in my printer the best print temperature is 180°, then I will set my Slic3r with 185° for the first layer and 180° from the second layer!
PS: keep an eye during print for this test is not a bad idea… last steps, from 190° to 175° may be difficult for some filament, so if you’ll see that your extruder start to lost steps you’ve already below best temperature and you can stop your print!
All kit printer have, normally, the firmware already loaded to with calculate parameters that will be, more or less, correct for that printer…
…but after lot of time each single printer are little different from the sisters, so those parameters may not more be perfect!
One of main parameter to verify, and change if needed, to obtain correct printout is the DEFAULT_AXIS_STEPS_PER_UNIT, you can found it in configuration.h file inside firmware source files:
You can use Prusa step calculator (https://www.prusaprinters.org/calculator/) in order to verify that your firmware are basically correct for your component, for example for my GEEETech i3B with calculator I can easily verify my 80 step per unit in X and Y:
But maybe this calculated value is not correct…
… verify is really easy… just print 100x100.stl:
Measure with a digital caliber the effective size of desired axe and use an easy proportion to calculate new step_per_unit value, old_step:100=new_step:measured, so new_step=old_step*measured/100.
Then just put in the configuration.h file like this:
Then upload your firmware and re-print test to verify that, now, 100 will be real 100, or redo procedure if is not!
PS: of course this procedure is valid for X, Y and also Z, for Z you just need to print 100x100x100.stl file