hi all,

im turning a large, 6 start, internal acme thread in a V60R vertical lathe and an osp200L control. ive got my depth of cut set at only .005" and the spindle keeps momentarily "stalling" and trashing my tool.
i have the infeed angle set at 31° so that i am cutting with the tool tip only on infeed. i feel like this should be childs play but the spindle just doesnt seem to want to cooperate. any ideas?