Tension is critical: a slack wire bows under heat and lags on corners, ruining accuracy. Anchor one end solidly and pull the other through a spring (a stiff extension spring or a constant-force spring), so as the wire expands when hot the spring takes up the slack and keeps it taut. Crank the tension as high as the wire survives without snapping cold — nichrome and stainless take a lot.
Many builders mount the wire to a small insulated arm or pivot at each carriage so it can follow tower movement on a 4-axis machine. Re-tension if you change wire length or gauge, and always tension before you power the wire, not after.
Many builders mount the wire to a small insulated arm or pivot at each carriage so it can follow tower movement on a 4-axis machine. Re-tension if you change wire length or gauge, and always tension before you power the wire, not after.