Hatch First Fit

Once we had recovered our workspace from the hurricane interruption, we proceeded to fit up the hatch frame - the two outside ribs plus the top and bottom crossmembers.  Yesterday we completed the fitting and temporary assembly, then put the results in place on the trailer hatch opening.

 

Above is the right side showing how the hatch fits inside the trailer side.

 

The above view shows the bottom edge.  Note the notch at left is to receive one of the interior ribs.
 

The above view is of the hinge edge.  A 1/4" gap is maintained between the hatch and the main part of the trailer to allow for the hinge.  The square piece of plywood attached to the hatch is temporary, maintaining some rigidity while handling and fitting the frame.  The two large notches in the lefttmost crossmember will receive the interior ribs.

In all, we couldn't have been happier with the initial fitting.  Note the alignment of the reference lines in the foreground of the above photo - they are within a small fraction of an inch.  

There was, however, one slight miscalculation by your editor on the bottom edge (see middle photograph.)  The vertical placement of the two bottom edge boards is approximately 3/4" higher than intended.  This is owing to the fact that the tapered (bottom) edge of the notched board must align with the rabbeted edge of the rib; in fact, the placement was made to align with the outer profile of the rib.

The solution is simple - rip down the pair of boards by the required amount, taking it off the square (top) edge, and add the same amount to the board that mates to the back of the trailer.

The bigger issue now, though, is that we are beset by a Nor'easter which was supposed to visit rains and wind upon us, but so far as dumped probably 3" of snow instead.