David Wong
05-23-2014, 9:17 PM
This is the second part in my series "What not to do when setting up a Japanese plane". In the previous installment, I showed the results of bad ura-dashi (tapping out) resulting in a badly cracked blade. Today, I am illustrating how I managed to crack the corners of the chip breaker.
Excuse the poor photos, but you can see how the corners are cracked in a dog ear-ed manner.
https://lh3.googleusercontent.com/-WF-MLCTbCqM/U3_pyKi0RjI/AAAAAAAAAjo/wOOFzAjXOFA/w800-h600-no/DSC02014.jpg
https://lh3.googleusercontent.com/-dQckXuhJhG4/U3_pw_29PDI/AAAAAAAAAjg/ZgT6nEFIO1Y/w800-h600-no/DSC02018.jpg
The damage occurred when I was fitting the chip breaker to the dai. The fit was tight, so I was using a combination of filing the mimi (ears) on the chip breaker, and filing the osae-bo (chip breaker pin). The main blade had very skinny lands on the back, so during the test fit, I must have had the corners of the chip breaker on the lands with the rest of the blade unsupported. This most likely resulted in the cracks. It took me several hours to grind and hone the chip breaker to correct the mistake. The chip breaker bevel is at 25° with an ~50° micro bevel. The chip breaker for this plane is does not have a maker's mark.
Excuse the poor photos, but you can see how the corners are cracked in a dog ear-ed manner.
https://lh3.googleusercontent.com/-WF-MLCTbCqM/U3_pyKi0RjI/AAAAAAAAAjo/wOOFzAjXOFA/w800-h600-no/DSC02014.jpg
https://lh3.googleusercontent.com/-dQckXuhJhG4/U3_pw_29PDI/AAAAAAAAAjg/ZgT6nEFIO1Y/w800-h600-no/DSC02018.jpg
The damage occurred when I was fitting the chip breaker to the dai. The fit was tight, so I was using a combination of filing the mimi (ears) on the chip breaker, and filing the osae-bo (chip breaker pin). The main blade had very skinny lands on the back, so during the test fit, I must have had the corners of the chip breaker on the lands with the rest of the blade unsupported. This most likely resulted in the cracks. It took me several hours to grind and hone the chip breaker to correct the mistake. The chip breaker bevel is at 25° with an ~50° micro bevel. The chip breaker for this plane is does not have a maker's mark.