Just bought the Oneway coring system and tried it out by coring a 15 1/2" maple bowl blank, which I admit might be asking too much of the lathe. Got a couple of cores out of it but it took some time and the headstock got quite hot. .. probably too hot.

Cored at a slow speed (275 RPM) and took my time but the headstock got quite hot, ... probably too hot.

Would like the cores but don't want to damage the lathe. Am I missing some techniques, or am I just asking too much from a lathe of this size?
Thanks for your help,
Trevor