Calibration
The Calibration process of your 3D printer must be done in stages. Although fine tuning can still be done iteratively lateron, it is essential that you don't skip any steps.
- Try to get your printer as "square" as possible. While the absolute values between the corners (vertices) are not so important, it is essential that the distances are equal (as in the threaded rods must be parallel).
Skipping to provide this will result in all kinds of unforeseeable behaviour that is at the same time very difficult to diagnose (e.g. Skipped steps caused by a binding axis is hard to diagnose). - Also check the diagonal distances as without controlling them you could have a parallelogram shaped configuration.
- As part of the calibration process check that your extruder can provide a constant feed. Problems could be caused by extruder gears not engaging properly, badly printed gears, bad hobbing, clogged hobbing, stripped hobbing, weak stepper etc.
When you finish the first step you can proceed to
Depending on your electronics, stepper motor, extruder gear ratio and final transfer surface diameter (aka hobbing or gear or whatever..) the E-steps per mm required by your specific machine is probably unique. That means You need to find it out yourself.
It is not as difficult as it might initially seem:
You can approach it either scintifically or with guesstimation, but in the end both methods need to have the fine tuning to be done the same way (and even if there is some minor error left SFACT will compensate for that).
The scintifical initial approach will give you a base feedrate based on calculation of micro stepping rate of your electronics, step angle of stepper motor gear ratio between stepper and extruder shaft and final transfer surface diameter.
As I find that it is easier to make 1-2 more trials than trying to pull that information together I will just explain the guesstimate method..
Assumptions and Tools Needed:
- You know how to/can update/flash your Firmware.
- You have a working Connection between your Computer and Your Printers Electronics.
- Your host software (preferably pronterface) is set up correctly to send and receive information/commands to the electronics and You know how to jog/send commands.
- Calipers, preferably digital. If you dont have You need at least a decent ruler. But You will need the calipers in the end so go and buy some..
- Filament. Preferably in a light color as You will need to make markings on it. You should do calibration with the material you intend to print mainly with..
- Felt marker with fine tip (in a color that will be visible when marked on your testing filament). If you have black filament only, pencils are known to work on black filament.
The Calibration Open the configuration file (most probably config.h) of your current firmware with your current configuration. If you are unsure, reupload it, it is essential that you know your starting point. Search for a line that says something like E_STEPS or STEPS_PER_MM. It can be that the values are expressed as a group of four (eg: (40.0,40.0,987.0,327.0)) then you have to use the last value that is E. Stage1: Ro
E-Steps per mm = ( Expected IN-trusion of filament * Current E-Steps per mm in Firmware) / Actual IN-trusion of filament