Well, you guys are contagious, worse than cholera!
Guess you know that. So last week we were talking plane wood.
I had made a number of plane knobs before, but it
was never really fast or comfortable work. Usually more waste
involved mounting it to a lathe and a pretty slow process with
several steps and some element of risk.
Drilling counterbore holes in completed turnings is
just waiting for any misstep to ruin your work. So I began to think about how knobs could be made
I looked at a bunch of factory knobs, various
Stanley and others. I measured and thought for a few days. I
stew these things. Let them simmer on the back burner of my mind for
a while. Its my style.
I came up with something. Here is what I came up with. Lovely huh?
For fast secure mounting I incorporated the diameter
of the most common relief hole in the bottom of every knob. The hole
over the threaded boss at the base of every knob. (This is a little
smaller than 5/8" btw). And a large screw.
I turned a piece of scrap 5/8" rod and fitted it for
a hanger bolt, the kind you use for table brackets.
While I was at
it, I cut teeth into the top of the rod to further grip the knob
blank when it was screwed in tight. I turned the other end down at
the end to fit into a 1/2" drill chuck for my lathe.
A morse taper would have been better, but I still
have a terribly crappy lathe (a dreaded AMC) that has no taper
shafts. I tapped the hole for the screw to mount it and set it
At the end I took a file and deepened and sharpened the threads
some. The rolled factory threads were a bit shallow. I had to pay attention to how long the finished screw was.
Too long, I can't counterbore for the brass nut. Too short it
In use the blank is cut, special attention taken to square both
ends, and center marked. Then I use the drill bit (that I altered to
the proper size...... pain. I need a 19/32 drill bit if anyone has
one handy??) and drill out the bottom pocket first.
Then a smaller drill is
run all the way through, for the screw mount.
Here is a small scrap of leftover walnut being rough
turned. As you can see, this it really good access.
A blank is mounted very quickly now, and I have very easy access
for turning every part of it. Its also easy to drill the counterbore
to fit the top screw right at the lathe with a chuck/drill mounted
in the lathe tailstock. Nice and secure, greatly reduced craftsmanship of risk.
When finished, all I have to do is re-drill the center to the
proper standard size which neatly removes the threads and all traces
of mounting except maybe some scars up at the top of the bottom hole
that nobody will ever see.
There is little danger drilling, because the counterbores at each
end are already done and the center hole is not a tight or critical
fit. Merely clearance for the screw. It is terrifically more efficient than turning schemes I had done
Here is my first trial knob on the mandrel, a Stanley large low
early beaded knob in fir, and the second, a Sargent beaded low knob
for a VBM, in black walnut. (OK, I like the early beads, kill me why don't you?). Rosewood being what it is, I didn't want to commit what precious
little 2" stock I had for trial work.
PS. If you ever wondered why Stanley switched from low to high
knobs, its very simple. It takes nearly 2" stock to turn a low knob.
High knobs can be done with a bit over 1 1/2" stock.
When it comes down to ordering suitable sawmill stock in the
millions of board feet, this is a very very big deal. Its more than
a matter of just setting up the saw in the mill. Its obtaining
suitable material capable of making 2" stock out of at all, over
thinner planks, that is important.
I suspect the old growth Indian rosewood supply was already
starting to fade and they could actually get more lumber shipped by
Its easy to prove for yourself right now. Just go shopping for 2"
rosewood turning squares and then look at rough cut (slightly
over) 1 1/2" stock. You will see they are 3 to 1 easier to get and
much cheaper compared to just a little extra board feet in