Its not the stepper motors - its the basic design of having two motors doing the same job with no mechanical synchronisation. Most dual-z printers can suffer from it, but the CR-10 seems to be particularly bad because the wheels allow the X axis to twist in the frame. Printers with linear bearings tend to stay straight once they're properly set up. With the CR-10S, as soon as it finishes a print and turns off the steppers the weight of the X axis can cause it to drop slightly on one side by rotating the lead screw. You'll see it happen in macro if you put any weight on the X axis bar while it's powered off - it'll spin the steppers and move down the Z axis.
Now it may be worse on some printers than others as it could change depending on how square the frame is or indeed how tight the wheels are. Mine likes to drop about 2 steps so I know to correct it. Sounds like Andy's has done the same.
|