ebinmaine 68,481 #1 Posted January 8, 2021 Scrolling through the wormhole we all know as YouTube the other day and this popped up I know a lot of us have some serious challenges trying to get a drill bit just right and this looked like a great explanation. I've done some bit sharpening and had some mixed successes and failures in the past. Thought I'd share this method. 4 Share this post Link to post Share on other sites
JAinVA 4,623 #2 Posted January 8, 2021 That is a good video. The technique is slightly different than what I was taught many years ago. You know you got it right when chip coming out of the hole is the same size from one flute to the other. 2 Share this post Link to post Share on other sites
DennisThornton 4,769 #3 Posted January 8, 2021 Good. He grinds a concave on the heel where I grind a convex heel. But I think this method is easier and I'll try it next time. Thanks for sharing! Share this post Link to post Share on other sites
Kenneth R Cluley 535 #4 Posted January 8, 2021 Used to hand grind all my drills but got a drill doctor from my father in law, and it really does a good job. Especially on smaller stuff as at my age is more difficult to see and control. Share this post Link to post Share on other sites
DennisThornton 4,769 #5 Posted January 8, 2021 No doubt the small bits are less forgiving. Share this post Link to post Share on other sites
Ed Kennell 38,718 #6 Posted January 8, 2021 That is close to the way I sharpen a bit for metals like brass, copper and cast iron. Like Dennis, I grind a convex heel shape although I don't think it matters as this is just clearance to the workpiece. For hard metals, I grind the heel right up to the cutting edge for a better bite. The key is to keep it cool. I keep the bits wet by constantly dipping in water. Share this post Link to post Share on other sites
DennisThornton 4,769 #7 Posted January 8, 2021 Ed, I'd never thought about thinning the cutting edge to get a better bite though I've ground a steeper angle to help with that. But then the cutting edge is weaker and more likely to chip. Any grinding of a cutting edge is easily ruined by heat and a thinner edge even quicker. I too don't think that a convex or concave heel matters as long as it's out of way of the chip but I think I'll find the concave easier to grind. Just never thought about, just ground as I was taught. I too have a Drill Doctor but I tend to just grind what I need as I need it. Quicker for me. Share this post Link to post Share on other sites
ebinmaine 68,481 #8 Posted January 8, 2021 1 hour ago, Ed Kennell said: That is close to the way I sharpen a bit for metals like brass, copper and cast iron. Like Dennis, I grind a convex heel shape although I don't think it matters as this is just clearance to the workpiece. For hard metals, I grind the heel right up to the cutting edge for a better bite. The key is to keep it cool. I keep the bits wet by constantly dipping in water. First of all, thanks for your responses guys I appreciate it. Ed, why does the thickness of The cutting edge matter for the hardness of the metal? Share this post Link to post Share on other sites
Ed Kennell 38,718 #9 Posted January 8, 2021 1 hour ago, ebinmaine said: Ed, why does the thickness of The cutting edge matter for the hardness of the metal? A really sharp knife edge will bite into a hard steel, but it will grab and try to take too big of a cut on soft metals. A bit with a flat edge as in the video will not bite into the soft metal so quickly. 1 Share this post Link to post Share on other sites
ebinmaine 68,481 #10 Posted January 8, 2021 2 minutes ago, Ed Kennell said: A really sharp knife edge will bite into a hard steel, but it will grab and try to take too big of a cut on soft metals. A bit with a flat edge as in the video will not bite into the soft metal so quickly. Niiiice. New knowledge. Thanks. Share this post Link to post Share on other sites
Pullstart 63,109 #11 Posted January 8, 2021 Step one. Get my 6” grinder out from storage after 3.5 years or so. Step two. Sharpen bits. thanks EB! 1 1 Share this post Link to post Share on other sites
oldlineman 1,482 #12 Posted January 8, 2021 Another important thing is to have a good stone with a flat surface, and yes a steady hand, not quite as easy as we grow older. 1 Share this post Link to post Share on other sites
DennisThornton 4,769 #13 Posted January 8, 2021 1 hour ago, oldlineman said: Another important thing is to have a good stone with a flat surface, and yes a steady hand, not quite as easy as we grow older. The vid showed moving the bit back and forth which would help dealing with a less than perfectly flat surface but of course that would be the first thing to address. Little point in sharpening a drill bit on an undressed stone. And yes, while I find that I've gotten better with many things as the years roll by I'm not hopeful about bit sharpening... Share this post Link to post Share on other sites
WVHillbilly520H 10,374 #14 Posted January 9, 2021 When I was in the machine shop, I often used a 6" wide belt sander of about 120grit I actually felt I did a better job on the wide belt vs a narrow stone unless doing 1/8" or smaller bits, I also learned that the cutting edge angle (steep/shallow) if varied would cut harder or softer metals better. I need to get in my tool chest and pull out the index and snap a couple pics of the different regrinds I have done. 3 Share this post Link to post Share on other sites
ebinmaine 68,481 #15 Posted January 9, 2021 2 minutes ago, WVHillbilly520H said: When I was in the machine shop, I often used a 6" wide belt sander of about 120grit I actually felt I did a better job on the wide belt vs a narrow stone unless doing 1/8" or smaller bits, I also learned that the cutting edge angle (steep/shallow) if varied would cut harder or softer metals better. I need to get in my tool chest and pull out the index and snap a couple pics of the different regrinds I have done. I'd appreciate that Jeff. We pretty much use drill bits for either wood or Wheelhorse steel. If I need to keep two sets I would. 2 Share this post Link to post Share on other sites
WVHillbilly520H 10,374 #16 Posted January 9, 2021 5 minutes ago, ebinmaine said: I'd appreciate that Jeff. We pretty much use drill bits for either wood or Wheelhorse steel. If I need to keep two sets I would. Mainly steels/metals in my former profession. 1 Share this post Link to post Share on other sites