Machine tool and display control device

A display control device comprising:

• a processor controlling display of an operating state of a machine tool including (i) an attachment portion to which a tool is attachable, (ii) a numerical controller controlling rotation of the tool in accordance with a machining program and (iii) a vibration sensor detecting vibration of the tool;
• and
• a memory storing various programs including the machining program and set data,
• wherein the processor calculates a first rotating speed on a basis of a vibration level detected by the vibration sensor when the vibration level has exceeded a predetermined value;
• receives a change instruction for changing a second rotating speed to the first rotating speed, the second rotating speed being a rotating speed when the vibration level has exceeded the predetermined value;
• and
• (i) performs control to display, on an operation screen, the first rotating speed, the second rotating speed, and a ratio display indicating, along a scale, a change ratio of a rotating speed to a third rotating speed specified by the machining program, the third rotating speed being a program-command spindle rotating speed represented as 100% on the scale, and (ii) performs control to display the first rotating speed at a position in the ratio display corresponding to a change ratio of the first rotating speed to the third rotating speed,
• wherein when the processor has received the change instruction, the numerical controller performs control to change a control command value of a rotating speed of the tool to the first rotating speed.