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Grinding a large drill bit.
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Previously:
https://www.homemadetools.net/forum/...409#post169737
https://www.homemadetools.net/forum/...114#post157488
https://www.homemadetools.net/forum/...695#post174654
I grind mine from the leading (cutting) edge. I guess you grind that one how ever you can hold it.
That doesn’t look right on so many levels.
Yeah. On a disk sander. Very straight cutting edge, control of included angle, and limited heat.Quote:
Originally Posted by Floradawg
So where is the grinding gauge, unless he is just removing bad material prior true grinding. I won't envision the load on machine or part from unbalanced cutter profile.
Like Skun Knuckles,(love your handle mate!), I thought that doesn't look right then I realised he is probably 'dubbing' the angles to put more pressure on the central part of the cutting edge.
I hand sharpen using a variety of methods while I'm still capable and have found that the method demonstrated here: https://www.youtube.com/watch?v=y0SQkzScQk0 at Tom's Techniques is very quick and does a great job on the majority of sizes I use. It is also one of the easiest to teach someone else how to sharpen a bit and have success.
I like to use Secondary Point Angles,(SPA),on anything above say 1/4"/6 mm as described on page 2 of this excellent article from Newman Tools. It certainly makes a difference in bit use before a resharpen.
Attachment 38499
Great job of explaining the proper technique. I usually roll the drill to attempt to replicate a factory shape but it is probably easier and a better result obtained your way. I will use your method next time I need to hand sharpen a twist drill.
I don't think I could lift that drill let alone grind it. Defiantly prefer core drills.