[gold83rg]

I have a Miller Sync 250, it welds fine but i find my ceramic cups are breaking far too much while welding Aluminum. Does anyone have an idea of what could be causing this?

[Otto Nobedder]

Yes.

Way too much heat reaching the cup. Stick your tungsten out farther. Don't try to "walk the cup". Up the gas flow a little for cooling.

Steve

[sschefer]

Stop dropping the torch when it's hot. . Seriously though, if the cup is hot and you smack it against something it will crack. I have that problem when I'm working in a tight spot and I bang the torch around.