It can be quite confusing when you’ve set a circle to print and it comes out an oval. Here’s why this can happen and how to fix it:
Signs circles are not round:
Pretty obvious most of the time, but sometimes they can be only slightly off so be sure to look out for them.
Explanation:
Oval circles instead of round ones are usually due to a mechanical problem. On tiny circles only a few mm in diameter, blobs usually along the Z-scar, might cause the circle to look oval instead.
Occasionally it can be down to having differing steps/mm values entered for the X and Y axes. This can happen (rarely) by EEPROM value corruption, but usually comes down to a user-induced fault.
For more details, read our standalone articles on 3D printed circles not coming out round.
How to fix:
Check axes, belt tension, pulleys and gears are tight, clean and in position.
Check different steps/mm in the slicer for on of the axes has not accidentaly been input incorrectly.
Be careful when entering new settings via the printer’s manual front-panel controls, we’ve all experienced ‘finger-trouble’ before and hit something on the controls we shouldn’t. Double check everything was input as it should’ve been.
Check the Z-scar to prevent blobs altering the shape. See [Blobs and 3D Printing Zits].