Reason being is many rip saw machines utilize an algorithm to estimate the largest square board possible from the piece of lumber being scanned and reduce the overall board footage slightly before calculating the yield. Depending on the yield calculation parameters your machine uses you might receive a reading higher than that. So if you ran the board through your machine you would expect to receive a rip yield rating of 83.3%. Then with the same board run it through your machine and see what you get.ДЇor example, if you are using a 6вЂќ wide board and were to rip it down to 5вЂќ you would expect a yield of 83.33%. One way to test the accuracy of the rip yield calculation on your machine is to first calculate your expected rip yield manually. It is this estimate that is used for the rip yield calculation and from our perspective can actually overstate lumber yield anywhere from 8 to15%. In essence, many machines will digitally scan the board and make a board size estimate based on what the board would look like if it was square. Manufacturers with set ups that do not account for the randomness of hardwoods could be left with a misunderstanding of their rip yields.ДЇrom our research many of the yield numbers provided by rip saw machines display a rip yield that is contingent on the board being square prior to ripping. However, a vast majority or rip saws in production today do not. Much of this is due to the randomness of each hardwood board.ДЇortunately, modern rip saws do a better job in accounting for this randomness with advanced scanners and algorithms. Over the years, lumber scanning designers and engineers have struggled to create a program that accurately measures hardwood lumberвЂ™s true effective yield. The random nature of hardwood lumber plays havoc on automated rip yield scanning and reporting. TodayвЂ™s manufacturing process is one of high precision inputs, outputs, and calculations.

Almost always, it is at the rip saw that the random nature of this raw material creates a challenge for manufacturers. Random widths, random lengths, and slightly tapered boards are the norm. Industry professionals know hardwood lumber is not normally sold square. However, many times this is not a true depiction of the true overall lumber rip yield. Many times they come to this point of view because they rely on the rip yield numbers from their machine scanners. Most manufacturers believe they achieve rip yields much greater than what we mentioned above. In other words, leave more edge waste at the mill. A two percent rip yield improvement on an $18,000 load of lumber can save you $360 per load in raw material costs alone! Not to mention that when you improve your rip yields you get more usable lumber per board to work with. That is why increasing your rip yield, even if it is only one or two percentage points, is so important. Using this calculation we have found that a manufacturerвЂ™s true lumber yield from converting random lumber to ripped two edge lumber can typically range fromД§5-85%. We feel it has been proven to be most effective.

When discussing rip yields with customers we usually start with the simplest calculation we know. In situations like this, companies may not have an accurate understanding of their true rip yields and the impact it has on their business success. Others simply trust the readings they have on their rip saws and assume those readings are their lumber yields.ДЇrom our experience, when scenarios such as these exist, companies may be losing valuable profits. Rather, they choose to measure their yield based on the number of products they can produce or by the amount of waste they have to throw away. Others have stopped calculating lumber yield all together.

In many instances, companies have become accustom to utilizing long standing estimates of their lumber yields. When it comes to ripping, where even a good system will generate 15-20% waste, yield is significant.ДЇor many in the industry true lumber yield becomes one of the most challenging calculations to accurately measure. Probably one of the most important calculations we work with is yield. Board footage, surface measure, cost per thousand, and clear cuttings per board are all common every day calculations we work with. People involved in the hardwood lumber industry are familiar with numbers.

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