The purpose of developing the portable CMM measuring instrument is to meet the requirements of workpiece coordinate measurement in harsh environments. It has the characteristics of convenient carrying, accurate and reliable. Let's take a look at the superior features of portable coordinate measuring instruments in mold design and production.
Figure 1 It is a nightmare to try to measure a large number of heavy molds into the constant temperature quality control room of a fixed CMM coordinate measuring machine. If a portable CMM coordinate measuring machine is used, it is sufficient to install the measuring device next to the part to be inspected. No other method is required.
A coordinate measuring machine (CMM) is a measuring instrument for measuring the length, width, and geometric dimensions of 3D objects in the X, Y, and Z coordinate directions (see Figure 1). Because the traditional CMM coordinate measuring device is a relatively heavy fixed measuring device, it is necessary to place the detected object on the measuring machine for measurement. In general, the purpose of developing a portable CMM measuring instrument is to meet the requirements of workpiece coordinate measurement in harsh environments. It is portable, reliable and reliable. The best CMM coordinate measuring instrument is equipped with a telescopic rocker arm with joints. The structure is strong, movable and flexible. It can accurately and repeatedly measure the geometry of the object. Its measurement accuracy can reach 0.0002in (1in = 25.4mm). .
The user can directly mount the measuring device on the machine tool that processes the part, and then guide the contact probe to the surface of the measured object to perform scanning measurement. At the same time, the laptop begins to display the 3D measurement process on the screen and records all measurement data. Essentially, it can create a 3D "blueprint" of a part, or a "blueprint" of machined parts needed to make this part. A measuring instrument can be used to check whether the mold meets the quality requirements and perform CAD to part analysis or even reverse engineering analysis of dedicated parts.
Digital processing of sheet metal parts
Sheet metal processing shops often program their regular cutting templates and then apply these programs to the operation of new laser cutting machines, water jet cutting machines, and automatic stamping machines.
The entire conversion process consists of scanning the contour of the model, and then the digitized data is input into the postprocessor in the format of a .dxf file, and the postprocessor automatically converts the information into NC NC cutting programs (see Figure 2). ). After working with a portable CMM coordinate measuring machine, it used to take a full day of programming work and now takes only a few minutes to complete.
Figure 2 Detecting a part in process with a portable CMM coordinate measuring machine. It is not necessary to disassemble the mold to analyze where improvements are needed. Simply check the existing mold and compare it immediately with the original CAD file. Portable CMMs can accurately measure worn and damaged parts, then create a 3D model and enter it into CNC files
Vintage CAD Drawing Updates
After the sheet metal cutting program is created, an updated part drawing will also be created using digitized data and AutoCAD software. In order to increase production capacity and production level, these templates need to be frequently modified in the workshop, but they are not recorded in software files. The result is no accurate drawings. If you use digital data to update the drawings, you can ensure that the drawings are consistent with the actual model.
This method is also suitable for updating the drawings of tools and fixtures, because these drawings often need to be modified several times before production. Measure the data set in the production and feed the data back to the CAD system to update the drawings. This saves several hours of trial run time and corrects errors that the tool needs to rework in a few years. This type of measuring device with a telescopic rocker arm is ideal for this field because the mold can be measured without disassembly.
Creates perfect parabola graphics
The molded satellite dish with a diameter of 8 ft (1ft = 304.8 mm), the performance of which depends on the perfect closeness between the contour profile and the parabolic pattern.
It is impossible for a manufacturer to spend hundreds of thousands of dollars to purchase a stationary CMM coordinate measuring machine to measure their molds. Instead, they use a microphone when testing the product's functionality, placing it on the center of the satellite dish and analyzing the captured noise. According to the analysis results, the mold was modified and a new satellite dish was re-pressed, and then further experiments were repeated until the clearest sound was received. This is a long and arduous process.
Today, a portable measuring device can be used to scan the surface of a measuring mold. The surface profile generated by the measurement system is superimposed with a perfect parabolic graphic using computer-aided design software. The inconsistency between the two superimposed patterns indicates that the mold is not too deep or too shallow, but also understands its depth.
In order to correct this problem, you can use the portable measuring device again to identify the problem and mark the relevant places on the mold for further rework.
Scan contour edges
Most CMM coordinate measuring instruments can only acquire measurement data of some discrete points within a predetermined interval. The portable CMM coordinate measuring machine can manually scan the continuous contour surface.
Recently, a new field of application has been developed for portable measurement devices, which are used in the aviation industry to measure those trimmed parts. Most laminated composite parts need to be trimmed during the final assembly process to achieve very accurate dimensions (see Figure 3).
Figure 3 Some portable CMM coordinate measuring machines also have a laser scanning function, which can acquire thousands of measurement point data per second, which shows great advantages for detecting complex parts, and can use these data for reverse engineering analysis and Finite Element Analysis (FEA)
The part's robotic cutting program is copied into CATIA software. The value of the first artifact can be used to verify the accuracy of the cutting program. Ordinary processing techniques require the inspector to use a template for cutting, and then verify the condition of the trim according to the shape of the cut. Using this process may take a whole day. Now it takes only about 2 hours to set up a portable measurement device that uses CATIA software to scan a thousand measurement points along the entire perimeter of a complex part. The measurement accuracy is greatly improved, and the NC programmer can obtain the feedback information of the parts he needs in the same time.
Re-engineering of existing parts
A production facility in the aerospace industry recently encountered a series of projects requiring them to redesign existing parts and import them into CAD software. This work requires the modification of parts that have been used by customers for a long time, but in fact these parts are still in line with the requirements of customers.
The original design on the desktop was already a product of more than ten years ago. The design history of these parts and the modification of the mold were not marked on the drawings. The portable CMM coordinate measuring instrument can scan the part quickly, and can carry on the fast digitization to the scanned data, then convert into the format of the 3D computer part design, and finally transmit these data to the computer system.
Portable coordinate measuring instruments are an effective measurement tool. It ensures that the mold can produce accurate parts and provides retrospective quality control documentation for reverse engineering analysis of new products. They provide manufacturers with the data they need. These data are accurate and well-adapted, which helps improve product quality and process levels.
They can also save a lot of money from them, including saving the cost of transport and measurement of indoor measurement fixtures. Moreover, the price of the portable CMM coordinate measuring device itself is much cheaper than that of the fixed CMM coordinate measuring device, but it has a considerable measurement range. If the same size mold is tested on the CMM meter, the investment required for the fixed CMM is more than 4, 5 times higher than that of the portable CMM.