Concave Table Base

 

Concave base mirror table

Concave base mirror table

A custom concave table base was required on which a large black framed mirror could be mounted. The client wanted a unique display table for their optometrist business. A sturdy design was developed for the base section that blended well with the mirror while maintaining an elegant double concave surface on the base.

White LEDs around the inside edge of the mirror frame were also fitted to illuminate the display area. The table base was constructed of timber and was finished in a high gloss black enamel.

To make the concave surfaces an intricate timber framework was built on which the plywood surfaces could be attached. To keep the weight to a minimum sections of ply were cut from the ply panel components that were not structurally required. This had the added benefit of allowing access inside the base to ensure good adhesive bonding of the edges of the concave surfaces.

Routing the curved profiles for the support structure

Routing the curved profiles for the support structure

Completed internal framework prior to cladding

Completed internal framework prior to cladding

First concave 5mm bendy ply section attached

First concave ply section attached

Cladding in ply completed

Cladding in 5mm bendy ply completed

The LED strips around the inside edge of the mirror were powered by small battery packs fitted in recesses under the mirror in the base section. The LEDs were divided into two sections with a battery pack fitted either end of the table base.

Side view of concave table in shop

Side view of concave table in shop

View of the mirror top showing LED strips

View of the mirror top showing LED strips

Cabinet Sides and Assembly

Temporary assembly

Temporary assembly with staples to mark out dowel joints


Carrying on from the previous post on the cabinet construction the side panels were cut in a jig so they matched the bevel on the curved front panel. Once they were completed the top, bottom and intermediate shelves were cut with a radius that matched the inside radius of the front panel.

The completed parts of the cabinet were assembled in the original moulding form and held together with staples so the position of all the dowel joints could be determined. The cabinet was then disassembled and the holes for the dowels drilled. Since none of the joints were 90 degrees a special drilling jig was made so the holes could be drilled at 77 degrees.

Once all the dowel holes were drilled the parts were glued and pushed together. This proved a difficult task because of the tapered sides. Nothing could be pushed in squarely and, because of the angle of the sides, it was difficult to apply a force in the required direction for the joints to close. Eventually everything came together and the frame could be clamped and left to dry.

The above steps are illustrated below.

Making the sides

Side panel ready for routing using the front panel template.

Routed side panel

Side panel after routing the 45 degree edge to match the front panel.

Cutting the curved top, bottom and shelf panels

Cutting the curved top, bottom and shelf panels with a router

Drilling dowel holes

Drilling dowel holes with a 77 degree drill jig

Aligning drill jig

Looking down the drill guide to align it with the mark for the dowel position

Cabinet panels drilled and dowelled

Cabinet panels drilled and dowelled ready for assembly.

Assembling the cabinet frame

Assembling the cabinet frame

Cabinet frame clamped

Clamped and glued cabinet frame

Once the glue has dried the drawers need to be made along with the top splash board and back panel. The next cabinet post will deal with these items and the fitting of the handles, legs and marble top and splash board. The completed side cupboard can be seen on this page.

Cabinet Door Cutting

Completed door section fitted with hinges

Completed door sections fitted to the centre support with hinges to keep them aligned.


After cutting the shape of the cabinet front panel the side edges now need to be mitred to 45 degrees. This allows the sides to fit squarely and hide the end grain of the front panel doors.

The curved panel remains on its support frame to hold it parallel to the horizontal. A jig is built around the panel to provides a flat surface along its side edges so a router can be used to make the mitre. A template is made of each side curve and this is attached to the jig to guide the router along the edge.

Care needs to be taken because a wrong cut now will render the curved panel useless requiring another to be made. This would be a very unpleasant task to undertake at this point of construction.

The steps involved in completing the front doors of the cabinet are illustrated below.

Cut cabinet door

Cabinet front panel cut to shape on the bandsaw. A 45 degree edge now needs to be cut.

Making curve template

Tracing the curve of the cabinet front to make a router guide to cut the 45 degree edge.

Routing jig

The routing jig built around the front panel to form a flat along the side edges for the router to move along.

Routing the cabinet front edges

The curve template is attached to the jig frame and the router is ready to make the cut

Completed routed edge

View along the front panel edge showing the completed 45 degree cut

Cutting the doors and drawer fronts

Cutting the door and drawer sections with a jigsaw

The two sides now need to be cut to match the front panel curves. The router guide used for the 45 degree cut on the front panel will be used in another jig so the cuts will match. The next post will illustrate the making of the sides and assembly of the cabinet frame.

Curved Cabinet Doors

Custom side cabinet design

3D rendering of custom side cabinet design


There are several steps required to make the curved cabinet doors required for the custom design shown on the right. What complicates this design is that the curved doors are also tapered. This makes the join line between the sides of the cabinet and the curved doors non-linear. The join line is further complicated because it needs to taper in to hide the end grain of the sides and the doors.

The first step is to make a curved panel that can be cut to the required shape. The only way to make this is to make a form that has the same radius as the door, and laminate several sheets of 3 ply together inside the form.

The glued sandwich of plywood is placed into the form and clamped in place with heavy weights until the laminate dries. When the panel is removed it is the same shape as the form.

The following photos illustrate the steps involved in making the curved cabinet doors panel.

Bottom form frame

Completed bottom form section with the required radius ready for cladding

Framework for upper form section

Completed framework for upper form section ready for cladding

Form frames covered in plywood

Form frames covered in plywood

Upper and lower form sections

Completed laminating form.

Glueing laminates

Applying glue to both faces of the plywood sheets with a roller prior to placing them in the form

Ply sandwich in weighted form

Five glued plywood sheets clamped into the form and weighed down with 700kg of pavers

curved panel

The completed laminated curved panel for the front of the side cabinet after removal from the form

Routing the jig frame

Routing the radius for the curved panel support frame. This will make the curved panel easier to handle.

Panel support frame

The completed panel support frame ready for cladding in ply

Cutting the curved panel

curved panel clamped to the support frame ready for cutting

The next step is to cut the two doors and drawer fronts from the tapered curved panel. This requires a special jig to be built so the elliptical curve between the sides and the door can be accurately cut. These in turn will need to be held in position for the mating of the side panels and central hinge support. The next blog post will illustrate the steps involved in this process to make the curved cabinet doors.