Hi, Bathgate
Are you running it steps per 1 full rotation or steps per deg (one full turn dev. by 360 = steps per deg).
If steps per deg then you probably need to set the Vel and acceleration way up in Motor tuning,
For Rotational View in Config General Logic Config., select Angular Properties check for A axis, Rotational, check options you want.
In Config, ToolPath Config., Rotations check x or y, A-Rota. Enabled and Use Diameter For Feedrate.
My Sherline Table is 144072 steps per turn or 400.2 per deg. vel 2500 accl 500, it turns fast.
Hope this Helps, Chip