Knife Sharpener Prototype (?)

Implementing my knife sharpener took longer than expected, at least partly due to the surprising number of different machining steps it needed.  The knife holder needed three drilled/tapped holes and a 1/2" hole for mounting it on the base.  It also needed a recess milled to accommodate the thickness of a washer used with the mount.  The mount is a 1/2" diameter aluminum rod that was cut down to 7/16" and threaded so it could be bolted to the base.

The mast also required some machining -- in this case, a 1/2-20 threaded portion to bolt it to the base.  The pivot piece was machined from Acetal, and needed some machining so it could be attached to the mast (and also permit the sharpening rod to pivot).

The sharpening rod has two Acetal blocks screwed to it.  They are used to hold the sharpening stone.  I also had to fabricate a handle and place it correctly so the operator could not be cut by the knife.  Making the handle took a number of steps, too, but it turned out pretty nice.  I used brass for a bit of eye candy.

Anyway, here is the result:

The photo shows the knife installed in the holder.  It is not clamped down -- there is a recess on the back of the holder where the back of the blade fits, so it is held securely enough while it is being sharpened.  In use, the sharpening rod rides in the slotted piece that is attached to the mast.  The height is adjusted to get the desired bevel angle (in this case, 20 degrees).

After using this on a couple of knives (starting with an inexpensive one I didn't care about much), I have figured out that I need to make a couple more pieces.  First, I need another rod/stone holder assembly, for a honing stone.  Right now I've got my water stone installed, and after that I hone the knife using a freehand approach.  I also will make another pivot assembly that will be installed above the first one.  In combination with my honing stone I should be able to produce a nice secondary edge that will last a long time.

By the way, the base is a hunk of oak veneer plywood left over from our house project.  The feet are wood dowels that were turned to size on my lathe, then some rubber floor-protector feet were installed over them to protect the counter top.  Since I've got bolts projecting from the bottom of the base I definitely had to have SOMETHING to elevate the base above the counter and this approach seemed the simplest to implement.

At this point I have less than $50 invested in this (including the stones).  That may go up a bit after I make the additional rod/stone assembly.