Completing the Roof Structure, Creating the Electrical Cavity, and More

Over the past two days much has transpired.  For starters, the roof lattice has been completed, including the fore-and-aft framing for the exhaust fan.

The next step here is to fit the two remaining pieces of interior plywood and cut the hole for the vent fan.  Part of dimensioning that hole will require building the "curb" that will fit between the ribs and the cross-members and provide a flat surface on top to which the fan will mount and a flat surface on bottom to fit the fan's trim ring.  Also required will be pseudo-ribs mounted to the sides of the curb box that will receive the inner and outer plywood.

Once that plywood is in place, the next step is to create the basics of the electrical cavity in the front of the cabin so that the wiring process may be started.  This cavity will have one horizontal shelf and a top.  The front will have two drop-down doors on the top portion and a removable closure on the bottom which will match the doors in detail.  The bottom will be made removable instead of hinged for ease of access with a mattress in place.

Below the three cleats are seen rough-fit - the top one will support the top shelf, the middle one will support the internal shelf that will carry the Xantrex, and the one on the floor will back up the face frame.

Below is the face frame, cut but not attached:

 

The section to the left in the picture will be the top, and will be the electrical cavity.  The bottom section will be pure storage.

Both sections will be fronted with 3/4x1-1/4 or so framed door panels.  The top panels will be hinged on the bottom and drop down, limited by hardware.  The bottom panel (it may be one, it may be two panels, not yet determined) will be a "drop in and latch" approach.  With a mattress on the floor, this lower panel will not be able to hinge from the bottom or the top.  Since the cavity will represent seldom-accessed storage, the panels covering it will be treated differently - that is, the bottom will key on the face frame and the top will latch.  Access to the cavity will require opening the latch and lifting the panel out of position.

I felt that we needed to document some details not shown previously.  Thus, the photos below are all details you might have observed, but are presented here with explanations.

 

Above is the detail of the main yoke meeting the port side, as seen from the rear.

The main yoke was created when we realized that we didn't have enough 1/4" oak as supplied to laminate ribs long enough to run from the front to the galley partition without embedding ribs formed from two pieces.  Since the task of creating two-piece ribs added a layer of complexity that we wished to avoid, the only option was to interrupt the ribs at such a point that our stock could be used to create laminations from one-piece members.

The main yoke consists of three parts - the center piece which runs from side-to-side of the trailer, and intersects the outer and inner ribs, bolting into the verticals supporting the forward part of the main rib, and the forward and aft yokes that receive the outer and inner ribs that are embedded in the roof.

Below is a view, from the rear, of an inner rib both forward and aft of the main yoke.

 

Below is a detail of the main yoke, seen from beneath and forward.

Below is a view of the galley partition yoke, from the rear.  It, too, is comprised of three layers - working from rear to front we have the hatch hinge mount (3/4" oak), the galley partion (3/4" birch plywood), and the rib yoke (3/4" oak.)

 

The galley partition and the forward rib yoke are held in elevation to the top of the internal rib, while the hatch hinge is held to the exterior profile.  The plywood sheeting of the front/roof will lie on top of the interior ribs, thereby fitting into the recess created by the hatch hinge as shown above.

Finally, we present a visual:  poplar ribbons created by planing the cross-members.  This is pure visual fun.