A few questions for all of you using the Drill Doctors.
1. What is the monthly or annual volume of drills being sharpened?
2. What is the condition of the drills needing to be sharpened. Are the tips chipped, or just dull?
3. Do you use both the coarse and fine wheels? According to the manual for my older DD750 the coarse wheel is to be used mainly to remove material to eliminate chipped cutting edges, while the fine wheel is for light touchups and finishing.
4. On average how much time is spent on each drill from start to finish, excluding time to split points?
5. Do you sharpen left hand drills?
One thing I noticed on my older DD machine is that while it could handle angles of 118* and 135* it would only handle those 2 specific angles, and standard twist drills. There is no provision (at least that I could find) to sharpen those with a slower or parabolic twist or different point angle. That may not be important to some, but in the last few years I've found the parabolics work better for clearing chips in deep holes. Reducing and in some cases eliminating the need for peck drilling.
The nice thing about the Black Diamond machine is that is has the capability of sharpening any tip angle from 80* to 140*. Another nice feature is with the collet system it can handle fractional drill sizes from 1/16" to to 3/4", numbers sizes from 1 to 70, and letters from A to Z. I currently have collets for all the fractions, letters, and numbers down to #30. I looked into additional number collets, but at $42.00 per copy I can buy a lot of number drills at less than $1.50 per unit before they would be cost effective.
I'm not trying to talk anyone into spending the money for a Black Diamond unit unless you stumble across one in decent shape in a price range similar to what I paid. I'm just noting the differences in capabilities between a "hobby" grade machine, and a "professional" grade one. In my opinion the DD is an adequate machine for low volume basic drill grinding. The BD or other professional grade machines have what I would consider the luxuries, or bells and whistles that come in handy when confronted with a variety of materials, point angles, relief angles, and twists.