Thursday, November 5, 2015

Cabin Parts

Areas of the main hull that are above and outboard of the deck are made of composite panels.  The panels are divinycell covered with carbon and an outer skin of fiberglass.  Some of the panels are flat while the majority are curved.  One curve has been used for all of the panels so that the builder only needs one mold.

I had mold frames cut at Turnpoint Design out of MDF.  Using a CNC ensures the frames are identical and also had the side benefit of adding puzzle joints.   The mold surface is about 12 feet long, so the puzzle joints make it easy to connect the fairly large sheets.

Three frames will be anchored on sheets of OSB perpendicular to the shop floor.  The too face will be two sheets of 1/4 inch melamine attached across the mold's top curved edge.

The plans also call for a laminated beam to support the curved foam cabin top.  The line for the beam can be taken off of a  mold as shown above.

Prior to starting on the curved parts,  I have been assembling flat panels.  I can use a sheet of melamine on top of my work table while it is still flat.  Flat panels make up the cabin dome and the bunk.

This photo shows two pieces of foam that form the dome top.  I perforated the foam in a one inch square pattern to allow air escape in the vacuum bag.  I need to make a perforation tool that pokes more than one hole at a time.  Presently I used a cordless drill on matching panels that are clamped together.

A layup of 2 or three layers of fabric is done and then the sandwich is clamped to the melamine.

This is a fuzzy shot of an untrimmed panel coming out of the bag.  The outermost layer is fiberglass to add a little toughness to the skin.  The glass is visible across the window and on the edge.

I trim the excess cloth off the edges and then cleanup using a flush trim router bit.  The pattern is the part's twin clamped to the working piece.  Some parts don't come in pairs, so I'll have to use a batten.

This shows a cross section of the fir cabin beam molded off of the jig above.   The beam is 9 feet long and 30 x 50 mm thick.

Task time: 65 hours
Total project time: 919 hours