The Finished Product

The Freshly Oiled Timber and Polished Stainless Steel.

After Additional Polish and Oiling of the Timbers

Manufacture 2

After the frame has been built the timber slats need to be made. Due to the 25x50mm thickness of the timbers I needed to glue the timber I had sourced together and cut them to the required size.

After the timbers are removed from the clamps they are put through the thicknesser to get them to the correct thickness they were put through a number of times alternating the sides to get cleaner sides.
One of the other edges is run over edge of the buzzer to get a clean and square edge which is used with the ripper to get a good edge on the fence. The face which went through the rip saw is then put through the thicknesser to clean up the surface.
The timbers are then docked to the required lengths.
The saw is then set to the 1.6mm depth and the rebated tensions are then cut in the ends of the timbers 50mm from the edge.

Cheers to Pat for taking care of most of the timber process for me.

The timber was finished with Danish oil, this aided in sealing the timber and protecting from the environment.

Manufacture

The stainless steel was collected from my supplier and taken to my shed at home.

The first stage of the construction of the chair was to cut the section to the required sizes along with the angles, these were all derived from reading the technical drawings.

Once the sections had been cut and the burs removed the top, rear and front frame sections were tacked into position with the TIG welder.

Once the sections are tacked into place the sections where these parts need to be welded they then are and the timber housing are then part of the frame.

The next stage of the built is to construct the 'V' shaped face section for the front face of the section shown above and the rear face for the section shown below.

Once these 'V' sections have been attached and tacked most of the welding can be done. The large welds take time due to the stop and start method which i used to prevent the frame from warping excessively. 

Note the tack welds along the 'V' section of the rear legs and the close spaces along the length of the strip, this prevents the 'V' section from warping and pulling away from the RHS as it is welded.

This image shows the process of welding along the length of the 'V' section. The burn marks show the sections where the weld has been created and the spaces between show tack burns.

The next stage is to cut a section of the corners out to put in the radius corners, the corners are marked 25mm in from the edge and a cut is made along that line. A curved section is then cut out between these two initial cuts, creating a void for quarter section of the 50mm pipe to be tacked into place. once tacked the excess material is removed and the welds are completed.

The next stage sees the finishing of the frame sections, the welds are ground back, if holes are found they are re-welded and ground back again, the surface is then finished with a sanding disc to smooth off the surface. The next stage is to remove the burn marks from the surfaces that need no finishing (welds), this requires the use of an acid called pickling paste, the paste is applied to the weld and surrounding area eats the burn marks and is washed off and repeated if required. The final stage of the finishing takes place now, I use a special scotch brite wheel on a straight grinder which helps to remove the harsh marks of the the sanding wheel and creates a brushed polish look on the surface of the stainless.

Technical Drawings

Model

The model was constructed from plastic RHS section and balsa wood.

The Final Concept Drawing

Concept Development 3

The final stage of the development was the sourcing of the dimensions of the stainless steel section from my supplier. After going through the range of RHS and the varying wall thicknesses and the suitable size of 50x 25mm with a wall thickness 1.6mm was selected. This meant that the radius of the corners would be 25mm and a section of pipe would also be needed.

The image shows the front section of the chair with the radius corners

The image above shows how the chair would be constructed through the cross sections. The front section of the chair required a 'V' shape section of material to run across the front face to keep the face flush.

The rear legs have the same on the back face for the same purpose. With the timber housings welded to the reverse sides.

Concept Development 2

The second stage of the development was to measure the modified chair for dimensions and to redevelop the design with regard to the new dimensions.

This image shows the initial idea and the basic idea of the size and the basis of the frame and the timber connections.

This second image shows the alternate idea of construction for the chair.

This final image shows the final concept of the construction of the chair, with the timber able to slot into the holes cut in the timber.

Concept Development

After consultation, I decided to develop concept 4.

The main issues that needed to be developed were the size of the materials that would be used in the production of the concept, the seating position and the fabrication methods which would be used to construct it.

As a result of the seating position issue and starting with a bar stool as inspiration, I needed to source another chair to modify to find the seating position I found suitable for my design.

This chair provided an ability to be modified to find the required seating position due to the round bar frame as it is easily cut, bent and welded due to the malleability of the section.

The rear legs were cut 50mm below the seat of the chair and were pressed back until the fresh cut met the seat of the chair and welded into place. this provided a more relaxed seating position for the user, while this chair was still usable the rear legs of the new chair would need to run back further than that of the back rest.