Post
by RitchievanDaal » Sun Jul 26, 2020 11:49 pm
The problem you are referring to is commonly known as 'layer shift'
Commonly 3D printers don't have positional registration, meaning the stepper motors move relative to their last positional command.
The stepper motor however cannot verify if it actually moved to the correct position, it just assumes it did. There is no feedback-loop.
So, for example, if you would physically hold the head, or bed of you printer whilst it is moving, the printer would not be able to register that stop of motion and will simply move as intended after the stop, but in a different location.
This can happen because of a few reasons;
1. Inertia - Your printer is moving too fast in relation to the strength/torque your stepper motors have.
This happens a lot in printers which have heavy moving components, for example a bed on the Y axis.
Sudden starting and stopping can cause the printer to miss steps, or the belts to skip teeth even.
- check your acceleration settings, or printing speed altogether.
2. Unexpected collisions - Your material settings are off causing 'zits' and 'blobs' or other deformities (warping), which collide with the nozzle which can cause a loss of steps.
- check your material settings and perhaps lower your printing temperature.
3. Aenemic steppers - Some printers come with steppers that have too little torque for the hardware they're supposed to move, or the stepper drivers provide to little power to the steppers. This is perhaps the hardest to modify, especially if you are new to the field.
- There is a small '+' screw on the stepper driver, turn this very carefully clockwise to increase the voltage. BE VERY CAREFULL WITH THIS AS IT CAN FRY THE DRIVER/MOTOR! Use a multimeter to measure what you are doing and watch a tutorial before you do this.
4. Obstructions along the X and Y axis rails - sometimes after a couple of prints small debris inherent of 3D printing can form and fall into the printer, if this debris gets into the V-grooves of the profiles it can cause resistance or rightout block motion along that axis.
- Check if you can manually move the X and Y carriages smoothely.
In conclusion is can be a combination of factors and it might actually be,
I would start with step 4, then step 2 then step 1 (the order of steps one and 2 are interchangable actually) finally step 3 if the problem isn;t solved.
I would not recommend trying more than a single step/change at a time though!
Hope this helps,
