Control Method and Portable Power Tool

A control method for a bore-chiseling portable power tool for machining a substrate by a drill bit, wherein the portable power tool has a tool holder for holding the drill bit on a work axis, a rotary drive for rotating the tool holder about the work axis, and a striking mechanism for striking the drill bit, comprising the steps of:

• superimposing a periodic striking on the drill bit at an impact rate and a rotating of the tool holder at a rotational speed in a rotational direction;
• identifying a material of the substrate being machined by the drill bit by a sensor;
• adjusting the rotational speed and/or the rotational direction to a first rotational speed and a first rotational direction when the identified material is an iron-based material;
• and
• adjusting the rotational speed and/or the rotational direction to a second rotational speed and a second rotational direction when the identified material is a mineral material;
• wherein the first rotational speed is less than the second rotational speed and the first rotational direction is counter-clockwise and the second rotational direction is clockwise.

A portable power tool, comprising:

• a tool holder for holding a bore-chiseling drill bit on a work axis;
• a striking mechanism which has a striker moveable along the work axis at an impact rate;
• a rotary drive which rotatably drives the tool holder at a rotational speed in a rotational direction;
• and
• a control device configured to adjust the rotational speed and/or the rotational direction of the rotary drive independently of the impact rate.