Vern Humphrey
Member
Years ago I had a project to help a company in trouble. This company made high-tech machinery for the timber industry, including something called the Long Log Flaker. The Long Log Flaker resembles a locomotive and runs on tracks. On the front of the "locomotive" is a huge spinning disk. Bolted to the face of the disk are knives, and there is a hole (called a "pocket") behind each knife.
The "locomotive" moves down the track and a huge hydraulic ram feeds about 60 logs at a time into its path. The spinning disk and blades chew these logs into flakes about the size of a playing card, and those flakes are used to make Oriented Strand Board (OSB).
The problem was, sometimes the locomotive would jump the track and wind up in the basement -- can you imagine trying to get it back out, repaired and back on the track?
On investigation, I found that wood fibers would get behind the blades. The enormous pressure would force the blades outward, jam the disk, and the torque would turn the "locomotive" over. Further research showed that maintenance personnel were putting a 5-degree back grind on the blades -- which kept the cutting edge from being flush with the disk. And that was the problem.
I showed the President of the company the maintenance manual -- in the instructions on sharpening the blades, it said to put a 5-degree back hone on the blades.
The President objected, "A hone is not the same thing as a grind!" Yep -- but people who read what he wrote seemed to think it was. And his company was going bankrupt as a result.
The "locomotive" moves down the track and a huge hydraulic ram feeds about 60 logs at a time into its path. The spinning disk and blades chew these logs into flakes about the size of a playing card, and those flakes are used to make Oriented Strand Board (OSB).
The problem was, sometimes the locomotive would jump the track and wind up in the basement -- can you imagine trying to get it back out, repaired and back on the track?
On investigation, I found that wood fibers would get behind the blades. The enormous pressure would force the blades outward, jam the disk, and the torque would turn the "locomotive" over. Further research showed that maintenance personnel were putting a 5-degree back grind on the blades -- which kept the cutting edge from being flush with the disk. And that was the problem.
I showed the President of the company the maintenance manual -- in the instructions on sharpening the blades, it said to put a 5-degree back hone on the blades.
The President objected, "A hone is not the same thing as a grind!" Yep -- but people who read what he wrote seemed to think it was. And his company was going bankrupt as a result.
