It sound like you have one of the old General Drill Sharpening fixtures.
Learned to sharpen drills free had back in HS shop and still do most of the
time. However, someone gave me a complete General a few years ago and I
never did anything with it since I didn't have a grinder with room on the
left side of the fine wheel, where it was suppose to be installed.
As I got more into machining and got a drill press with low rpm for larger
bits, I found I needed a fixture to better sharpen the larger Morse taper
and Silver Deming drill bits.
I didn't have the instruction sheet for installation and operation of the
General, so I went to the hardware store where they still had them for sale.
I pulled the instruction sheet out of the box and ask for a copy. That done
I installed it and found it a PITA to get set for each drill, especially if
the were of significantly different sizes. I finally accumulated enough
redundancy in drills that I could switch drills and put the dull ones in the
box and sharpen them when I had enough to make it worth my time to adjust
the settings as I changed from small to larger sizes.
I think I finally found a web site that also had the instruction posted on
it. I don't have the link anymore but I might be able to find the copy I
have of the instructions.
One thing that bothers me about this General sharpener, is the fact your are
grinding on the side of a wheel that is not intended for this. This goes
against all the Safe Shop Practices that I have lived with for 50+ years.
(well most of the time and if I ignore SSP, I always stand to the side at
arms length with an face shield, etc.) Back to my point. I have always been
taught and have taught, never grind on the side of a grinder wheel that
isn't designed for that purpose. It under cuts the wheel and could cause it
to explode when grinding on the rim, as intended. My be I'm preaching to the
One thing about grinding on the side with the General fixture, you are
standing to the side of the wheel.
Bottom line, I can still free hand sharpen bit below 3/8 better and easier
than with the General fixture. From 3/8 to 3/4s it's a toss up. For the big
ones the General gives a better center and angles than I get from free hand.
IMHO, the General or similar fixtures, a 8" wheel would be my minimum, but
that is based on the fact, I just don't like to do any grinding work in the
smaller wheels. I also like at least a 1" or greater width. Not many home
shop grinder have the shaft length and guards for the thicker wheels. I had
to modify my HF 8" grinder to take my large stock of 1" wheels.
My experience and opinion, FWIW