Cutting forces in machining operations are of great importance because their characteristics are useful for predicting and detecting tool conditions and other occurrences. For example, one important and common problem shown in metal cutting is chatter, and cutting forces have a strong correlation with this phenomenon. Many researchers have worked in chatter detection and estimation using cutting forces. This work proposes the use of cutting force measurements and analysis of the frequency spectrum to detect chatter. The cutting force should be measured using a simple, compact, and low cost technique. Hence, in this work the measurement technique proposed in  of using strain gauges to measure the cutting forces is applied. Additionally, the previous design was enhanced and upgraded into a wireless system for monitoring. This new smart tool holder uses wireless technology to transmit the measurement data, and therefore removes various constraints the previous design had because of the use of wires. With the new design and added interface operations such as frequency response of the measured signal, a more functional online monitoring system was established. A peak in high frequencies was observed in the cutting test experiments when chatter appears.