Proven Automated Lumber Grading Systems
|Grade Mark Readers|
Frequently Asked Questions
In a traditional planer mill application, the ColorScan® reader head mounts on the trimmer's in-feed line, directly over the board feeder or lug loader. The control enclosure mounts at a remote location within 50 feet of this head. (The cable provided by Lucidyne is 50 feet long, other lengths can be provided.) In sawmill or other applications, the reader head is located at the grading area. The processor needs one lug space or about 30 inches of board travel to develop the solution.
The rating of each ColorScan® enclosure is NEMA 12/13. The entire system is water- and air-tight, and will function properly in up to 90% humidity. ColorScan® will operate from -34 degrees centigrade to 50 degrees centigrade. Temperature control of the ColorScan® reader head and control electronics is not required. Vibration under 10 cycles per second has no effect on system performance. Vibration above 10 hertz and of sizable magnitude may cause mechanical fatigue in the components over time.
Definitely not! Many hardwood mills have introduced GMRs into their production processes. Lucidyne's GMRs fit into both green and dry lumber applications. Anywhere a human grader is involved in passing off grade, trim, or sort instructions to a computer or PLC control is a potential site for a Lucidyne GMR. One innovative application is in front of an edger or trimmer optimizer. The saw operator uses the capabilities of the GMR to pass information to the optimizer that geometric scanners cannot see. The grade of the lumber, and defects, such as blue stain, are examples of this.
The trimmer operator's console should remain at its existing location. In the mill pictured at the right, the operator has been replaced by the GMR. While the console is not needed for GMR operation, if the scan head is damaged or the GMR power supply damaged by power surge, the trimmer can be operated in the manual mode until repairs are made. The same logic applies to lumber sorter control consoles. Indeed, certain sorter control functions, such as emergency stop, still need to be available for manual use.
ColorScan® is both optically and electrically filtered from ambient lighting conditions to achieve the greatest signal to noise ratio possible. In most cases a shroud is placed around the head to minimize any direct sunlight interference. ColorScan® applies the equivalent of 50,000 watts of light to the board during scanning. This results in reliable performance in all mill conditions. When mounted properly, ColorScan® is insensitive to normal mill lighting, both fluorescent and incandescent.
Lucidyne now offers a scan zone that ranges from 16 to 30 inches. our experience shows that almost all applications can work within 18 inches. In response to special circumstances, Lucidyne has provided longer scan zones for mills that produce lumber with considerable near-end wane. The scan head shown here was developed for Culp Lumber, New London, North Carolina. This head scans the near end of Southern Yellow Pine lumber searching for precision trim marks.
The highly efficient software and hardware combination used in ColorScan® provides full feature solutions in less than 400 milliseconds. A full feature solution would include FE trim, FE grade, center defect trim, NE grade, NE trim, fence, and scale-off. The rule-of- thumb is 40 milliseconds per character. Most boards are marked with fewer than three characters, resulting in solution time of 120 milliseconds.
Lucidyne offers both color recognition and black and white models. The main difference is black and white models do not recognize the color of the crayon or chalk. Color recognition is not needed in applications where only one grader is involved. In situations where two or more graders are utilized, recognition of the grade marks of each grader is important management information.
ColorScan® delivers accurate readings of at least 99.7% of all boards at line speeds up to 120 lugs per minute. ColorScan® will operate accurately at speeds up to 220 lugs per minute in higher-speed stud mill operations. The operating system allows for the capture of rejected symbols for analysis. Graders having trouble with certain marks can quickly see the problem and make corrections. Lucidyne's GMRs have been used with the newest rotary lug loaders to ensure that they can perform in the most demanding applications.
Graders are trained to put a thumb's distance between characters. For best results, lines should be no closer than 0.750 inches. This 0.750 inch allows fill-in for crayon skips and results in fewer errors.
ColorScan's® software is insensitive to changes in scale or comparative size of each symbol. The limitation on the low end is resolution. The limitation on the high end is a function of fitting the entire solution within the 18 inch window (on standard scan zones). Graders are trained to make marks that are about 2 inches. Marks less than 1 inch are not recommended.
No, Lucidyne neither manufactures nor sells fluorescent markers. However, Lucidyne has been instrumental in working with the manufacturers of fluorescent markers that are useable within a wide range of mill and environmental conditions. The markers come in a variety of colors and a range of hardness ratings. Both wax-based and chalk crayons are available.
ColorScan® recognizes up to ten colors simultaneously. Three groups of five different colors are recommended for multiple shift operations. The crayon hardness required depends largely upon ambient mill temperatures and wood surface conditions. Lucidyne has installed over 650 GMRs world-wide and will recommend crayon colors and hardness prior to installation.
The GMR can control a grade stamper, although this function is normally controlled by trimmer or sorter control systems. For example, in some mills, there are different grade stamps used for #2 Common between 2x4 and 2x6 product runs. ColorScan® can be configured to fire one grade button for 2x4s, another for 2x6s. The system tallies and labels the grades correctly for each width, and the proper grade stamp arm fires when needed. If the required interface to an ink-jet system can be configured like a grade stamper (discrete outputs at 5 vdc, 24vdc, or 120 vac), the GMR can control this function, too.
As each board passes under the reader head, the crayon symbol marked by the grader is displayed on the monitor. The corresponding ColorScan® character is shown at the top right-hand corner of the monitor. At the lower left of the monitor, a real-time display of production and accuracy is provided.
Boards with symbols that are not recognized are flagged as rejects and are handled as specified by the configuration setup. When the crayon color cannot be determined in color recognition installations, the trim and sort instructions are carried out, and the board is assigned to "Unknown" as a color.
Operating system parameters are pre-configured from the information supplied to Lucidyne prior to installation. Fine-tuning is done on site using the personal computer user-friendly menu system. ColorScan's® management report system is also designed to be completely configurable in the field.
ColorScan® has full cut-in-two and center defect trimming as well as shop lumber scale-off capability. In addition, ColorScan® can be mounted directly over the lug loader, and performs well even though it can see the symbols on multiple boards. Jump skids are not required before the trimmer to create an empty lug. ColorScan® supports close-coupled trimmer in-feeds where the board dealer must be inhibited for a cut-in-two or center defect solution.
Common keyboard skills are all that is needed to operate a Lucidyne GMR. Only a few keystrokes are needed to change between species and lumber sizes. Report formats are pre-configured and simply accessed. The only maintenance needed by most ColorScan® users is to keep the glass clean in front of the camera and lamps. The GMR computer is equipped with an Ethernet connection for access via the Internet for troubleshooting by Lucidyne's technicians when more extensive system maintenance is required.