mrcharly wrote:If you slackened off one of your screws (the ones holding the plane blade in place) and skewed the blade, wouldn't that cut a taper? Would only work on a tenon no longer than the width of the blade.
Obviously it would be better with a tapered hole, so that you could cut a longer taper. I'd have thought a tapered 'V' (which could be sawn) would work as well as a round taper.
I believe the old practice used to be to fit the legs before they were fully dried. This results in oval holes and oval tenons. Orient them in the right way and the fits gets tighter as the wood shrinks.
Finally getting around to older posts. Interesting. Maybe you could cut a short taper that way. Need to think about that. Trouble with this is that the hole is not tapered and I am not sure the piece would guide through the hole correctly. Would certainly work for approximate work. See Jenny Alexander's site for how to make a tapered reamer out of a keyhole saw blade. I made one per his instructions.
http://www.greenwoodworking.com/. Look under "tapered reamer." You are, of course, limited to the tapers available in keyhole saws, and a keyhole saw is not a common item these days, but the Japanese, bless their hearts, still make them and very nice ones too. Another alternative is a machinist's taper reamer. These are easy to find. If they will cut steel they will certainly cut wood. The bigger they are the more expensive, of course. Typically tapers in metal are much shallower than tapers in wood.
Still thinking about this, It is very easy to find a
step drill. This is a cone-shaped drill approximated by steps. Very useful for drilling holes in thin stock, wood or metal. You will have steps in it, but you could maybe file the steps mooth or sand them (anathema!) or something. I vaguely remember step drills with no step at all, continous all the way. Maybe my memory is at fault. Once again you are limited by the tapers supplied by the manufacturer.
A few years ago I got a
bung reamer in (gasp

) an antique store at (double gasp

) a very reasonable price. These things are about 1:6 or 1:7 taper. They have a short auger bit to start the bore. In the unbelievable days of old, when beer came in wooden barrels instead of plastic or aluminium kegs, these things were used to drill a tapered hole in the barrel, into which you inserted the
bung, i.e. a tapered peg with a tap at the other end. Proprietor of the pub put the barrel with tap on the bar; no CO2 pressurization needed, gravity did the work of drawing your pint. I consider this tool a treasure, very well made. Hope to use it to cut some tapered holes.
I Like the idea of tapered holes, and of course tenons. If you doubt this just look up
Morse Tapers on the 'net. You will be drowned by the information. If you own a pillar drill, the chuck is held in there by a Morse taper and absolutely nothing else. No grub screw, no locking pin, no glue, nothing but the taper. So in principle a tapered joint is far stronger than a cylindrical one. In wood we need much more acute tapers than in steel, because wood is softer than metal. If you let things dry out properly you can get by very well with circular holes and tenons. My dream is to build a chair with tapered holes while it it still green, and tap it in as it dries. But so far all I have is an impressive collection of failures.