The frame for the tombstone raised panel door begins exactly the same as a frame for a square raised panel door would. In fact, I begin by making a square frame using the proportions from the design posts above. I build the frame exactly like I would a square paneled door, including plowing the groove for the panel, sticking the molding on the top rail and coping the molding at all the corners. This gets me to the point pictured here.
A portion of the groove and molding on the top rail will be cut away later when I cut the arch in the rail, however, the shoulders will remain and the groove and molding remaining on these small sections will guide the carving of these elements on the arched section. It would be difficult to add these elements on the straight sections after cutting the arch and have them cope well at the corners so it’s easiest to do it before cutting the arch.
Once the square door frame is done, I lay out the arc for the top rail. I opted to do this on scrap first to make sure I got it right and it’s a good thing I did because I messed up the first try and ended up with an arc that was much too large. Using the scrap allowed me to plane away the marks and start over. If I had laid it out on the top rail, this would have been more difficult to do without altering the top rail thickness.
So I began the layout by cutting a scrap to fit between the stiles of the assembled frame. I then used a divider to step off the width of the exposed portion of the panel bevel on each side (the actual bevel will be a little wider because a portion of it will be inserted into the groove on each side of the frame). According to my design the width of the exposed portion of the bevel is 1/2 M (M= 1 module; see the design blog for an explanation of this). Then I step off another 1/2 M on each side for the width of the shoulder of the raised field. Finally, I use the divider to find the center of the panel.
Next I scribe the arc of the field from the center point. The radius is the distance from the center to the inside of the shoulder. Since the width of the exposed portion of the bevel is 1/2 M, I increase the radius by 1/2 M and then scribe the outter arc which is the arc of the exposed portion of the beveled section but also the arc of the top rail. On the scrap board this arc is a full semi-circle but on the rail it will not be.
To lay out the arc on the rail, I need to establish the center point. The center point lies on a line even with the shoulders of the raised panel field. Knowing that the exposed portion of the bevel is 1/2 M, I establish the line to locate the center point of the arc by scribing a line 1/2 M below the bottom of the rail. Then I use my dividers to find the center and scribe the two arcs, the inner being the field of the raised panel (for reference only to double check my layout) and the outter being the arc of the rail. As you can see, the arc of the top rail is not a full semi-circle because the center point is below the bottom of the rail.
Finally, I can cut the arc in the top rail. I used a turning saw to cut the arc just shy of the scribe line. The I used a 1/2″ #4 carving gouge to clean up the arc and pare it back to the scribe line. Just like paring a dovetail baseline the last paring cut was made with the gouge placed right into the scribe line left by the divider point. This is why I don’t use a pencil to do my layout, only to highlight the layout made by a scribing tool. You can also use a rasp and/or file to clean up the arc but a gouge is faster and leaves behind a cleaner surface so I like it better. After cleaning up the arc I put the frame back together to see how it looks.
In the next part I’ll tackle carving the panel groove and the molding back into the arched section of the rail.