Measuring flatness has at all times been a necessary a part of engineering and manufacturing processes, and with the development in know-how, varied strategies have been developed to realize correct measurements. These strategies embrace optical flatness measurement, profilometry, interferometry, and mechanical flatness measurement.
Optical flatness measurement is achieved utilizing interferometry, whereas profilometry makes use of a stylus to scan the floor and supply a 3D illustration of the floor topography. Mechanical flatness measurement includes utilizing a straight edge or a set of gauge blocks to measure the flatness of the floor.
Within the aerospace trade, flatness is essential within the design and manufacture of plane parts akin to wings, fuselages, and engine components. The flatness of those parts can affect the aerodynamics of the plane and, due to this fact, its efficiency. The automotive and semiconductor industries even have strict flatness necessities of their manufacturing processes to make sure that the ultimate merchandise operate as supposed.
When excessive precision is required, the instruments wanted to make these micrometer-level measurements begin to get fairly costly. For trade, instruments that value a number of thousand {dollars} won’t be too huge of a priority — but when a weekend hacker needs considered one of these professional-grade instruments, that form of price ticket is usually a bit an excessive amount of to abdomen.
A Toronto-based engineer by the identify of Bryan Howard needed a extremely correct device to measure flatness, however didn’t wish to spring for a high-priced piece of kit. As an alternative, he determined to give you a plan to construct his personal , utilizing cheap parts that he already had readily available.
With trendy picture sensors packing excessive pixel counts and low value tags, Howard noticed the standard webcam as an ideal sensing machine to make use of within the design of his machine. After eradicating the lens from in entrance of the webcam’s picture sensor to eradicate distortion, a horizontal line laser, from an off-the-shelf laser degree, was shined instantly on the digital camera from a distance.
With the laser beam staying in the identical place, an meeting containing the digital camera is moved throughout the floor of the article to measure for flatness in a collection of steps. The extent at which the horizontal laser beam intersects with the picture sensor’s pixels can then be measured at every of those steps.
Howard modified and improved an present software program device that calculates the precise place of the laser beam within the picture body and tracks the change in place over time. With a collection of measurements, it is ready to inform the consumer precisely how flat a floor is, or is just not, to inside about 0.5 to 2 micrometers.
The system is extraordinarily delicate — strolling round, and even standing up, whereas the measurements are being collected could cause a wobble that results in inaccuracies. Howard additionally notes that the system ought to be turned on for at the very least 5 minutes earlier than use to carry the picture sensor as much as full working temperature. Earlier than that point, there shall be some quantity of drift.
This challenge is not at all a plug and play resolution, however with the directions offered, anybody that has a necessity for such a tool is prone to even have the talents wanted to have the ability to put one collectively. And whereas there are a number of caveats that you’ve to pay attention to to get correct outcomes, taking a seat whereas the machine is in operation is nicely value saving a number of thousand {dollars}.Measuring floor flatness with a laser and webcam (📷: B. Howard)
Digital camera meeting, earlier than lens elimination (📷: B. Howard)
The applying interface (📷: B. Howard)
