After many years of flat wood woodworking I decided last year to take up turning. Bought a Jet 1221VS midi lathe and started developing my skills turning small to midsize bowls (6-8" diameter); exclusively working with green wood from the neighborhood. All was well until I decided my abilities had progressed to the point where I could take on bigger projects and I started mounting 12 inch blanks, mostly around 4" thick; maple, oak, ash, etc. When turning around the perimeter of these pieces (where obviously the force exerted on the tool is greatest) the motor constantly bogs down and sometimes stalls. This is a problem even when taking very light cuts, and it makes it impossible to make the continuous sweeping movement along the piece that yields clean curves, as I need to keep backing off to allow the motor to recover its speed. (I typically turn between 400 and 500 RPM - wouldn't want to go higher on these heavy pieces.) The problem disappears as I move toward the center of the piece, where the load on the tool is lighter.
Can anyone tell me if this is normal or if I have a defective motor? It seems odd that Jet would put a motor on their machine that isn't capable of handling the biggest pieces that will fit. (And by the way the lathe is plugged directly into the wall outlet and the belt tension is a high as I can make it, so I don't think I'm experiencing a voltage drop or slipping belt.) Not much point in making a lathe with a 12 inch swing if you can't turn a 12 inch blank on it. Advice/others' experience much appreciated.