NBE Scanner / Optimizers
www.millsmart.com/carriage.html - 503.625.4101- Updated 20-Dec-05
Robert Cecil was convinced that the world needed both front and back scanning on Headrig Carriages. His experience with other vendor’s systems convinced him that there was just too much guessing and not enough data. When Robert started working with NBE in 2000 he tried to convince me (Rod Nelson). Well, I am the person that forecast the demise of Carriage systems back in 1992, so he did not have much luck. But Robert was determined, so when JoeScan started making scan heads and they were proving to be extremely reliable, Robert went ahead with his plan. In 2003, he installed the first front and back scanner with scan heads riding on the carriage. He has done 4 more since then and has 2 scheduled for the first quarter of 2006.
OK, Robert was right and I was wrong. So, why do carriages still exist and why is front and back scanning important.
Why do carriages exist? Well no other primary breakdown machine can handle a wide range of diameters, lengths and log shapes, and produce products for any downstream machine center. It is the best machine for pulling high grade boards of the sides of logs. Carriages may not be the fastest but they are the most flexible.
Front and Back Scanning
Why do you need front and back scanning?
Historically, headrig scanners would only scan the front side of the log and attempt a minimum opening face. This would guarantee a usable first board, reveal the grade to the operator and preserve the most wood to be used on the backside. We like to call it the Dark Side, since it does not get scanned, and too little is know about it. On smaller logs or logs with no potential for grade improvement, this scanning method pushes all excess to the back, thus guaranteeing that wood is wasted on the backside.
Adding backside scanners gets the data needed to make best whole-log decision. Offset, taper and cant selection can be made prior to the first cut. If significant value improvement is possible at another rotation, the operator is notified. If the operator sees grade potential he can still select the conventional methods of opening and cutting the log.
The concept of minimum opening face needs to be forgotten. When NBE did their early cant optimizer, we spent a lot of time convincing people that sometimes a 6” or 8” opening face is the best decision. But we needed to scan both side of the cant to be able to make the best decision. No one tries to sell a cant scanner that only scans one side. Why would anyone want a log scanner that only scans one side?
Also over the years I have come to realize that most optimization code has been written to overcome insufficient data or bad data, or insufficient computer horsepower. These early optimizers required extensive setup tables with diameter, length, taper and sweep rules that would direct the optimizer to make a reasonable decision in spite of the deficiencies.
With surround scan, you have the necessary data and today’s computers are fast. So you can define your lumber products the same way as you would on a trimmer or edger and let the optimizer do the rest.
To Be Continued