Making a Rounder Plane: Part 2

In Part 1, I found that using a backer piece to guide the stick through the exit of a rounding tool can make a nice difference in getting a straight stick.  After rereading a section of Roy Underhill's book "The Woodwright's Companion" on rounder planes, I tried another.

This time I tried to make a tool with the straight (cylindrical) exit hole integral to the tool.  That is, bore a hole through the body of the tool, then taper the hole most of the way through, leaving the last 1/2-5/8" untapered.

This time I used a pipe deburring tool to make the taper.

And Roy suggests bedding the iron at 30 degrees to a tangent at the top of the circle

In this second experiment in making a rounder plane, I started with a 5/8" hole through a 2" thick piece of poplar.  I tapered the hole with a pipe deburring bit.  In the above picture, if you look closely down the tapered hole, you can just barely see that the far end of the hole is still cylindrical.

OK, this is weird and unsafe ...

Here's the exit end
(can you tell this chuck of poplar was formerly used as a chopping block)

For a number of reasons, I didn't have any success with this at all.  First, the iron was hanging about 1/2" over the front end of the tool and that's very unsafe.  Second, there were issues trying to incorporate the cylindrical section of the hole into the main block of the tool.  I really wanted the entire circumference of the exit hole to be supported - that is, I didn't want the top of the exit hole to be open as seen above.

The third thing was that this taper just seemed to be too great an angle.  It's about 30-35 degrees.  This makes it much tougher to get a workpiece started.  In theory it should work - it's just quite a lot tougher to work a piece of wood through it.  And it's very easy to get the first inch or so of dowel at an extreme angle to the workpiece we're using.  I wish I'd taken a picture of that one - it was bizarre!

After this experiment, I realized that I needed to make the tool with the taper going all the way through a 2" block of wood so that when the bed is cut the entire width of a spokeshave iron would be supported.  Also it would be much easier to incorporate a cylindrical section of hole by including a backing piece with a hole the exact target diameter that was glued or screwed to the exit side of the rounder plane.  As I'll write about in Part 3, that backing piece's hole needs to be in very good alignment with the central axis of the tapered hole.

Another thing that took some fiddling was that Roy suggests the 30 degree bed angle and to use the iron bevel down.  I had to adjust the bed a few times before it was deep enough for the iron to cut anything.

So experiment 2 was a failure.  But I finally got it right in experiment 3, which I'll write about next time.  Using a 6 degree tapered reamer for the hole, using a backer piece with the proper size hole, and getting the bed and iron adjusted just right make a huge difference.