I know this seems to be a common fault with Ultimaker Original machines, but I seem to have tried all remedies suggested and it still refuses to work!
Put Belt tensioners on Long belts
Tightened the short belts by pushing down the motor
Tightened the cross axis rod block (Thinner rods which mount to the print head)
Made sure hot end doesn't wobble/move freely
Checked extrusion rates
Tightened all the pulleys to the rods
Made sure the cross rods are square
The errors seem to be happening at 45* from the X and Y, so it leads me to think it's a belt (slack) issue, but with tightening every single belt, I'm at a loss!
I hope someone might have some suggestions?
Bottom right circle seems to show the defect clearly as it has gaps in the walls at half one and half seven. It should be solid like the other quarters.