This video by mrpete22 starts with a very well done illustration of the reason for a four facet grind. The initial illustration shows the common large chisel point bit. Mr. Pete explains the importance of using a smaller bit with a diameter of just larger than the chisel point for accurate drilling. The four facet point eliminates the chisel point and reduces the need for initially drilling a smaller hole.
Mr Pete is a retired shop teacher and a wealth of information. Here is the link:
https://youtu.be/cqn2VPGYA9c
Ken
I really like his videos, they are well done.
I am going to post a link to one that I found to be excellent. Ken, it does mention another brand of sharpener and opens with a picture of it, so if you need to give this the axe...... However, that is not the point of the video and it does not push that unit.
https://m.youtube.com/watch?v=EtnNN5pEjaU
It mentions a few reference books in it, some of which were available as downloads. I downloaded 3 of them in pdf format for a whopping cost of $0.00usd.
Elden,
Thank you for posting this link to the mrpete22 drill bit video. I certainly have absolutely no problem with showing the Lisle drill sharpening machine. It has a different target market than the Tormek DBS-22. I picture Lisle machines as part of a machine shop alongside Bridgeport mills, South Bend Lathes, and other industrial machinery. My guess is that very few of us have those in our shops. I do know that a number of us, including you and me, do have the DBS-22.
I have long considered the DBS-22 to be Tormek's most sophisticated jig. In skilled hands it really is a versatile marvel, capable of far more than my limited knowledge. Thirty years ago I wanted to set up a home machinist shop. While I still have the fascination, I long ago realized that the actual realization of that dream required a younger person.
Mrpete's extensive videos could stand a person learning machinist's skills very well. I certainly enjoy watching them. Armed with good knowledge and a DBS-22, a Tormek sharpener would be well equipped to handle even the needs of the most sophisticated home shop.
Ken