Mini Mill Fine Feed Z Axis Crank

Every time I use the boring head on my mini mill I've told myself I need to make a crank for it.  The stock knob for the fine feed is pretty small so it's a pain to run the cutter down & then back up.  I had held off because I had been thinking about a crank that's similar to the X and Y axes.  Then I realized that I just needed a longer lever (and a handle) to get what I wanted.  After that, I got to work and made this:

The crank is made of flat aluminum stock.  I made the handle out of brass and polished it up a bit using some quadruple-0 steel wool.  I used an off-the-shelf shoulder bolt so the handle could spin freely, and eased the head a bit using my lathe and ball turning attachment.  The crank is attached using a couple of drilled/tapped holes in the fine feed knob.

The ball turner turned into a project as well -- I figured out that its design really required a mod to the lathe so I could manually drive the lead screw (to drive the carriage).  So the first crank I made turned out to be for the lathe.  Of course, the handle isn't nearly as nice because I did not have a functioning ball turner at that point.

I had thought the crank would be in the way too much to leave it installed all the time, but it has turned out to be so handy that I haven't removed it.  When the fine feed is not engaged the crank hangs down, as shown in the photo.  I suppose if it gets too annoying I could come up with something to hold it in some other orientation.  But to date it hasn't been a problem.

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.