To hold the centerline on the workpiece will help the device shown in the figure.
Recommend to read
AVTOKRANA
Amateur constructors of boats, yachts, cars often face the problem: how to get the curve on the big plane? Enough to install on a building berth vertical panel, the edges of which drive...
GARDEN “HAIRDRESSER”
I worked as a mechanic gardening vehicles, or simply petrol lawn mowers. Often had to cut the grass and shrubs in inconvenient places, and in restricted areas. And the existing braids...