They do make drills with a left hand twist. Industry uses them in some machining operations. Nice to know about, but a pain in the neck when you are teaching kids about which way the drill is supposed to turn. Not necessary when using an easy out though - any twist, left or right hand will make the hole.
As far as the drill quality going down hill, I don't know if the quality dropped or there is just a higher percentage of junk out there now. The quality stuff can be found (Enco and MSC are two suppliers that carry good stuff) but the cheaper stuff is even easier to come across.
I keep my eyes open at yard sales and buy coffee cans of drill bits for a couple of bucks. Often there is some mix of quality, but I always get my moneys worth.
The other thought with sharpening - I have discovered just recently that it is common to run drill bits too fast. This burns them up, takes the hardness out of the cutting edge and makes poor holes and short drill life.
There is a balance between speed (rpm) and feed that optimizes drill life.
If the speed is too fast the bit rubs on the metal, not cutting but creating excess heat which removes the hardness (temper). If the feed into the work is too fast the chip being made is too large, doesn't break off and jams the drill, causing it to break. The chip also plays an important role of taking heat away from the drill Not enough chip, more heat to the drill.
OK, so what is a good feed rate?
With CNC machines they can program feed and speed so the drill does a spiral motion and the rate might be something like .005" feed per revolution. Your chip then would be .005" thick.
We can look at our chip and say "this is too thick, or this is too thin" What we need to see is that we have a good chip and a consistent chip. Consistent chip = consistent feed rate.
Again, how do we know we have a good feed? How about some trial and error?
Since burned bits are from too slow a feed, try feeding a little faster. Oil is always a good addition (it also helps take heat away). Watch your drill on contact - you should get a chip instantly. No chip means the drill isn't sharp. Check for two chips. Two flutes in the drill, both cutting edges should be sharing the load.
Peck with the drill. Pecking (also used in CNC) is drilling a little, then bringing the drill out to clear the chips and allowing an instant of air cooling, drill a little more, clear and cool, a little more, etc. This also breaks the chips so the long stringing chips go away.
Use a pilot hole. On anything over, say 3/8" drill a small pilot hole to start, then follow with the drill of choice. The point on your bit is called a dead center. It is dead (excepting split point drills) because it doesn't cut anything, it is metal plowing into metal. A pilot hole lets that dead center follow the hole and the cutting lips do their thing without excess heat from the center.
Finding a good quality drill? USA on it is a good sign. A fully machined, quality surface is also a good sign. This would be a fine, almost high shine anywhere you look. Machine marks (actually precision grinding marks) should be consistent, uniform and extremely fine. Color might have value - gold plating is an industrial hard finish. gray, shiny metal are normal finishes and black may be good, but flat black may be a sign of cheap imports.
The Drill doctor mentioned above can do a good job sharpening. In my experience most of the other sharpening gadgets are junk. With practice you can learn to sharpen drills "free hand" on a grinding wheel or, better yet, a belt sander. I do it all the time on a Delta 1"x42" belt sander.
Who is this "prolific" writer that is writing all this stuff? Currently I am a machinist/ metal fabricator/welder. Past work has had me teaching college students how to be high school shop teachers that teach metal work.
:2cents:
