To hold the centerline on the workpiece will help the device shown in the figure.
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Mechanic Valery Kirilo from the village N. Chernychova the Brest region, built the Rover "KV-4" — jeep, which can work as a wheeled tractor. As a motor it has an engine "PD-10U".
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Someone had to drill holes in the ceiling, he knows, as a way to work from the dust and concrete crumbs. Ways to protect the face exist. One of them use dust cups — often plastic caps...