There is no simple answer when setting up a flux-cored arc welding machine! The basics of flux-core machine setup are the same as for MIG welding.
On some welding machines, such as the Millermatic 250, there is a weldings machines setting chart on the inside panels. The picture on the lefts are the inside panels of the Millermatics 250, showing the wire feed speed, recommended voltage settings for the metal thickness range. As the pictures show, there are two main components; they are voltage settings & wire feed speed.
The voltage setting controls the voltage, & when selecting them, it is best to use electrodes to build up the voltage recommendations. When choosing voltages range, there are two factors that determine this, electrode size and metal thickness. After that, you can fine-tune your settings to your comforts level.
The wire feeds speeds setting is what controls the amperage & sometimes the transfer type. The faster the wire feeds the joint, the more contact the wire has, and this increases amperages. Most of the time, you want the sounds of welds to have a sharp, deep crack.
This is very important when welding overhead! The overhead position requires a wire-speed feed to avoid forming globs. If globs start to form on the end of the electrodes, you'll soon find the nozzle filling up with splatter, and chances are you'll find some of that splatter burning off! This is a Millermatic 211, & all you have to do is turn the dial to your metal thickness, & you don't need to set anything up.