Figure 1
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With the purchase of a lathe, another new skill has to be learned, grinding toolbits for the lathe. In my General Links Page I have a link to an article by Sherline Tools on grinding lathe toolbits. The article uses a method where the grinding table is tilted at 7 degrees from the horizontal, in relation to the grinding wheel. Unfortunately when I bought my 6" grinder, it came with fixed tables, not adjustable ones. I have a drawing for an adjustable table, but presently do not have it built. In order to try my hand at grinding the toolbits I came up with a simple modification for my grinder tables. Figure 1 shows the modified table.
The modification consists
of epoxying a 7 degree wedge of model aircraft plywood onto the original
fixed table. The lines running parallel to the face of the wheel
are made by the edges of the lamination layers in the plywood. If
you look closely you will see an angled line running between the edge closest
to the wheel and the first lamination line. This is at 10 degrees
from the wheel face. This is the other angle used in the Sherline
grinding method. Both tables (course and fine wheels) received this
mod.
To create the wooden wedge
I use my disk/belt sander as shown in Figure 2. The sander table
was set perpendicular to the disk, and the miter was set to the 7 degree
angle. The wood block was used to save my fingers from harm.
The plywood was then feed in while the miter/block combination was moved
back and forth to spread the wear on the sanding disk. After the
plywood was sanded down far enough the two wedges were cut out and epoxied
to both the grinder tables.
Figure 4 shows the grinding wheel dresser I bought locally. It was under $10, and made a world of difference in the cutting speed and lowered the temperature of the toolbit vastly. It is meant to be used on large grinders where the ledge at the bottom of the head can be hooked over the table edge to insure a straight cut, but it worked fine freehand.
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