Here are a couple of links that might help:
http://www.mmsonline.com/articles/choose-the-best-drill-point-geometry
http://www.newmantools.com/machines/drillpoint.html
http://www.gadgetbuilder.com/DrillSharp.html. This guy has an extensive site.
http://www.sciencedirect.com/science/article/pii/S0007850607609998 You need to be willing to pay for it.
http://stusshed.com/2010/08/29/drill-bit-sharpening/. This guy covers the fixture you are talking about but maybe doesn't answer a lot of questions.
http://homews.co.uk/page360.html. Harold Halls point of view.
A lot of links, but the subject is interesting and well studied. I'm sure you have seen some of them, there are probably more that can be added to the list.
Greetings to all . First of all I know this is an OLD thread. the original poster has not been here for a couple of months and the the two responders have chosen to move on to other forums.I am choosing to continue this thread rather than start a new one.
You may also want to read here
10" wet grinder
Grinding HSS tools
I have pondered one of these jigs. I have watched the videos and read the reviews. The reviews are excellent.Four facet drill bits stay cooler last longer and cut straighter.
The technology certainly has its advantages and frankly some disadvantages. For most people, in this case home shop owners, you need to ask is the additional complexity worth it. Frankly if you are doing a lot of stuff in brass or other alloys the grind may be more trouble than it is worth.
The only down side is the price . $272.00 seems like there are no bargain price they are shipped directly from tormek in many cases.
I've always have been of the opinion that the Tormek is over priced. On the other hand all of the DIY four facet fixtures out there for more conventional grinders pretty complex. For that price you could buy two of the cheap Drill Doctors or one of the better ones and have a dedicated machine. So you have to ask what will you gain for that high price.
The reviews say this is superior to the drill doctor . The other tough part of this route is you need a $250.00 to $500. wet grinder to put the thing on.
Conical drill points have been around forever, they are a general purpose solution. The Drill Doctor is actually a fairly innovative low cost solution to grinding conventional drill points. The thing here is that you will find that depending upon the materials to be drilled, four facet drills can be the worst choice relative to conventional grinds. If you are drilling materials where the bits tend to corkscrew or grab you really need a different approach yet again.
A tool and die maker once showed me an entirely different twist drill grind he uses when drilling sheet metal. This grind kinda looked like a brad point. The point here (yes a pun) is that different uses benefit from different approaches.
Beyond all of the above, I believe that a conventional grind with a split point gives you much of the benefits of a four facet grind for far less trouble. I'd seriously consider a split point grind if you are having trouble with a drilling process right now. I could be wrong but I believe most Drill Doctors support this. If you look at the geometry split points seem to be a compromise that is almost a four facet grind.
I have already invested in the 10" Sheppach grinder
I have thought about trying to make one but there are many pieces and this seems to be well thought out. So could spend many hours tying to figure it out and fabricate.
Has anyone here gone this route? Do you own a DBS 22 orhave you make one or found a cheaper viable substitute.?
Not me! As I've said above the buy in on a Tormek is too high for me right now. Might I go that way in the future - hard to say, I'm just short too many other important tools in the shop right now. Further it would seem to be more constructive to save up for a more conventional tool grinder.
I have an older generation drill doctor and it works OK . I have thought about upgrading to a newer one they have good reviews as well. But if the DBS 22 is in fact superior I may go that route instead.
Four facet grind does appear to be superior for demanding uses but you need to ask yourself is what you do that demanding to justify the added expense.
Are these worth the money? are they in fact Superior to the drill doctor? is four facet indeed superior to a good factory or DD grind?
If it was absolutely superior I think you would see more factories shipping drills with the grind. I have a hard time seeing it as a general purpose grind.
I have read things like the tormek DBS 22 makes the drill doctor look like a kids toy . And the four facet geometry lasts four times as long as a factory grind. so I am hoping someone can confirm this.
I wouldn't call the Drill Doctor a toy. It really is in a class of its own for what it can accomplish at the price charged. As for how long things last, the first thing I'd ask is are you having huge problems right now.
This is a rubber meets the road kind of tool. drilling is the most common matching task and a properly sharpened bit has no substitute. I have not problem investing in tools but do not want to waste money.
Tin
Tin
You are correct that a properly ground bit makes all the difference in the world. The problem here is that different uses benefit from different sharpening techniques. For example drilling Lexan and other plastics can benefit from a zero rake on the cutting edge. In industry you might see guys with more than one set of drill bits if the mix of materials they work with justify different grinds.
In the end there are no easy answers!
