Oscillator Quantitative Imaging Harbor Freight vs Rigid

Oscillator tools have become the go to tool for just about everything around the house. From cutting drywall to cutting baseboard, oscillator tools are perfect for the job due to their ability to rapidly oscillate between tiny cutting strokes.Many have undertaken the task of comparing the many oscillator tools on the market through product testing. This post will not attempt to reproduce that work. Instead, this post will leverage InnoSolve’s competence in quantifying video.

Frequency and Cutting Stroke

We will be comparing the frequency of oscillation and cutting stroke angle of two popular oscillator tools with the help of Digital Image Correlation (DIC) technology.Oscillator tools oscillate at about 20,000 cycles per second. This equates to about 333 Hz. If you wish to see an oscillator tool frozen in time you can sample a functioning oscillator tool at 333 frames per second (fps). However, a frozen oscillator tool is not very interesting so you probably want to sample at a rate that is at least 10X faster than 333 fps or 3,330 fps. 3,300 fps did not seem sporty enough for this post so we recorded at 16,200 fps. The photogrammetry targets were attached to the head of each tool without a blade in the analysis video. Photogrammetry targets were included on each tool’s body so that rigid body motion due to each hand could be taken into account.

Chicago Electric vs Rigid

The two oscillator tools show cased in this post are made by Chicago Electric and RIDGID tools. The Chicago Electric tool can be found at Harbor Freight Tools and costs about $20. This tool does not advertises an angle of oscillation. The RIDGID oscillating tool was purchased from Home Depot for about $80. This tool advertises 4 degrees of cutting stroke at 20,000 revolutions per minute (rpm).From just looking at the high speed video, it is difficult to accurately quantify how fast and at what angle of oscillation these tools function. Recording the two tools in operation side-by-side is a little better for comparison purposes but still lacks quantization. However, when DIC is applied to track the photogrammetry targets, the angle of oscillation and frequency of oscillation can be easily quantified.

DIC Analysis

From the DIC analysis, the Chicago Electric tool oscillates 3 degrees and the RIDGID tool oscillates a little more than the advertised 4 degrees. From looking at the time scale at 0.016 and 0.026 seconds, 4 oscillations of the Chicago Electric occur over the 0.01 second interval. This equates to 400 Hz or 24,000 rpm. In comparison the RIDGID tool completes 5 cycles from 0.01 to.026 seconds. This equates to 313 Hz or 18,750 rpm.In summary the Chicago Electric tool has a smaller cutting stroke than the RIDGID tool but the Chicago Electric tool operates at a faster rpm.