This Hound Will Hunt
Information is king when it comes to making value decisions, but it can also be a royal pain to manage with lumber whistling by at 3,000 fpm and over 170 lugs per minute. Add to the information you’re trying to juggle – MSR, moisture, geometric, and visual defects galore – and things get exponentially more complex.
November 24, 2011 By Scott Jamieson
This is the challenge that the folks at Concept Systems embraced in developing the Board Hound lumber tracker system, designed to manage lumber measurement information on a per board basis, from the edger or planer to the trimmer optimizer. The idea is to use all available data to drive the highest possible value-based optimization decision. Judging from results at its Beta site install in the Pacific Northwest, it’s right on track.
The first install has been in full production mode for over a year, says Concept Systems engineer Doug Taylor. It’s taking information from a Metriguard MSR machine (reading every two inches) and a Wagner Apex moisture meter system (each inch), and attaching the real-time key to those results for each board via two Domino A Series printers.
The mark itself is just a board ID, tied to measurement results that reside in the optimizer computer. That way, the amount of data that can be tied to each board is infinite. Taylor says two printers are used to ensure a very high level of reliability. The same “belts and suspenders” approach is used downstream to read the code just ahead of the trimmer optimizer, where four Cognex vision system cameras are used. This, Taylor adds, results in a mark recognition rate of close to 99.5%.
“As far as we know, there aren’t any other systems that track that much information at that speed (the planer mill runs at 3,000 fpm), with that level of reliability.”
The dimension mill makes lumber to 20 ft in length, and uses a ScanWare (FinScan) colour scanning system for 100% graderless grading. The Board Hound is tied into the mill PLC for a common interface with the ScanWare optimizer, which then combines MSR and MC data with its own geometric and visual readings to push the maximum value from each board at 170 to 200 lugs per minute.
In this mill’s case, that could mean dropping a 20-ft board to a 16 footer if it will allow it to make the next highest MSR value as a result. The options are limited only by imagination, markets, and sort bins.
The Board Hound is a retrofit system, demanding little in the way of mill modifications. Taylor cautions that the mill must stabilize the board as it enters the MSR system, to allow a consistent print orientation; and after the lug loader to allow a proper read. Both were accomplished at the first mill install with minor mechanical adjustments. “That, and about an inch of gap at 3,000 fpm is all we need,” Taylor adds. “The system is modular, using all off-the-shelf components, and so far the mill reports that maintenance has basically been replacing the fluorescent bulbs once a year.”
In short, it looks like a solution to an optimization challenge, not another mill problem.
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