What is the best tutorial on how to sharpen drills using the U2 grinder?

pontiac428 said:
Jeff, your problem from the photos above is clocking
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I think you are being kind. I need to make some little plates that attach to the end of the tool. I guess the one that comes with the machine are worthless.
Clocking, angles and set-up are the only things wrong with this grind :)
 
I rotated the flute stop finger out of the way on the front of my swing sharpener on the Sheckel. It was mostly useless. I align drills by eye with the cutting edge near vertical (ideally should be vertical when grind is complete). Check that the angle of the cone is correctly set using a machinist's protractor at the leading edge of a finished bit. The web should be thin and it should be 135 degrees (do not confuse with cone angle. This is simply 90 + 45 =135 degrees for the web angle). Going from Harold Hall's illustrations, you can look at the lobe profile and see what is wrong just by analyzing its shape. Once you get the clocking and the angle worked out, it should become clear what to do on the fly. Grind a coffee can worth of bits, and it's permanent memory.

I tried to upload the Harold Hall #30 tool and cutter grinding book and the Tubal Cain #12 drills, taps, and dies book, but they are too large to post as an attachment. They exist in the download library on this site.

Edit: Stickout will determine if your drill point is sharp and angular vs. rounded and curved. Just another thing to watch.
 
pontiac428 said:
I rotated the flute stop finger out of the way on the front of my swing sharpener on the Sheckel. It was mostly useless. I align drills by eye with the cutting edge near vertical (ideally should be vertical when grind is complete). Check that the angle of the cone is correctly set using a machinist's protractor at the leading edge of a finished bit. The web should be thin and it should be 135 degrees (do not confuse with cone angle. This is simply 90 + 45 =135 degrees for the web angle). Going from Harold Hall's illustrations, you can look at the lobe profile and see what is wrong just by analyzing its shape. Once you get the clocking and the angle worked out, it should become clear what to do on the fly. Grind a coffee can worth of bits, and it's permanent memory.

I tried to upload the Harold Hall #30 tool and cutter grinding book and the Tubal Cain #12 drills, taps, and dies book, but they are too large to post as an attachment. They exist in the download library on this site.

Edit: Stickout will determine if your drill point is sharp and angular vs. rounded and curved. Just another thing to watch.
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Thank you John!
As I learn more about drill bit geometry, I'm hoping to understand what you just said :)
I have watched a couple of Mr. Pete's drill bit videos. He is a good instructor, he speaks slowly and clearly with lots of visual help.

I need to go check out Harold Hall.
 
Jeff, this might be of some use. It's a diagram I made when I was trying to figure out drill point geometry so I could make a drill sharpener jig. You might not be not interested in the secondary point angle or split point relief facet. I added them to the diagram for completeness.
The primary relief facet angle, "A" (green facet), varies depending on the drill diameter but the other angles are constant for a 118-degree drill shown.
MSP Drill Nomenclature.JPG
 
Here I've extracted chapter 2 from Hall's sharpening book. I'm pushing this like dope because you won't be able to find your backside with both hands without it. I'll go further to say that chapters 1-3 from Tubal Cain's drills book is good information, but Harold Hall is the only place I have seen all of the information he presents in one place. The Mazoff paper is more of an exploration of point types than anything useful for actual grinding, but good if you're a nerd like me.
 

Attachments

  • 38 - Tool and Cutter Sharpening CH2 excerpt.pdf
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John281 said:
Jeff, this might be of some use. It's a diagram I made when I was trying to figure out drill point geometry so I could make a drill sharpener jig. You might not be not interested in the secondary point angle or split point relief facet. I added them to the diagram for completeness.
The primary relief facet angle, "A" (green facet), varies depending on the drill diameter but the other angles are constant for a 118-degree drill shown.
View attachment 345133
Click to expand...
Outstanding!
Thank you
 
pontiac428 said:
Here I've extracted chapter 2 from Hall's sharpening book. I'm pushing this like dope because you won't be able to find your backside with both hands without it. I'll go further to say that chapters 1-3 from Tubal Cain's drills book is good information, but Harold Hall is the only place I have seen all of the information he presents in one place. The Mazoff paper is more of an exploration of point types than anything useful for actual grinding, but good if you're a nerd like me.
Click to expand...
Awesome,
Thank you
 
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