Tuesday, January 29, 2013

Horned Smoother Part VII

Making this plane is proving to be an excellent learning experience.

It didn't work all that well at first—shavings were getting stuck near the mouth and those I pulled free were accordianed.

I took a class years ago where we made a panel raiser. And while, after four days, we learned how to lay out the lines and flatten a bed, and everyone left with a working plane, we didn't learn (or at least I wasn't paying attention at this point) why it worked.

So when my smoother wasn't working well, I had figure out why.

First, I reckoned that because the plane is high angle, the throat needed to be opened up. This meant changing the upper angle of the throat from 55º to 62º (an arbitrary number), which in turn made the wear more shallow.  And that meant the shavings had a shorter distance to travel through the narrowest section of the plane, plus I could reach stuck shavings more easily.

I started fiddling around with the scrolls at this point, but just ignore them until the next post.

Before tweaking.
Next, I had an epiphany. It's a no-brainer, but it hadn't really dawned on me until now: a full-width shaving needs an exit path—from mouth to top of plane—that equals a full-width shaving (don't say it....I killed too many brain cells in the drinking days of my youth).

That meant tapering the thin walls of the abutments (that hold the wedge in place) from 1/4" at the top of the plane to zero, and well in advance of the mouth.  It also meant that the wide walls of the abutment had to taper from the wedge toward the front of the throat and along its entire length.
After tweaking.

After that, the long arms of the wedge needed to be shortened so they matched the length of the abutment. I also shaved a steeper angle on the arms to provide more clearance for shavings.

One other thing--I made the wear as smooth as possible. It seems as though even small bumps or rough spots will snag a shaving.

Every day that I learn something new is a good day indeed.

*You may notice that the mouth opening is awfully large. I'll add an insert later on to tighten it up.