Why is it recommended to have the take up lever and needle of a sewing machine at its highest position?

It's essential to have the take-up lever and needle of a sewing machine at their highest position primarily to prevent snagging and bending the needle. When the needle is raised, it ensures that the threading mechanism is also in a position that reduces the risk of the needle getting caught in the fabric, which can occur if the needle is down when attempting to pull fabric or when starting a new stitch. This height position allows for smooth and effective needle movement as it enters and exits the fabric, thereby minimizing the risk of bending or breaking the needle due to incorrect tension or resistance from the fabric.

Maintaining this position also allows for optimal threading, although that is not the primary reason it's recommended. Other important operational factors like fabric feeding and tension adjustments are influenced by the overall design and function of the sewing machine but are not directly related to the positioning of the take-up lever and needle.