Touch Up

 

 

The stainless steel clamps look not very nice. So, they are replaced by plywood clamps. The new pair of clamps is 12 mm thick and 17 gr lighter than the previous one.

The stool looks much better with the new plywood clamps and the total weight drops a bit to 1977gr.

Final Work

The stool weighs 2059g. Its weight exceeds 2000g constraint (2.95%). To reduce the weight, plates have to be trimmed off, but only 35 grams were removed after the plates were trimmed, so the plywood need to be extruded to get the weight under 2000g. A 120 mm in diameter circle was marked at the centre of the plywood seat to be extruded about 3 mm in depth. After extruding, the weight drops to 1987g. The extrusion does not affect the strength and rigidity of the stool.

Here is the finished stool. It shows strength and rigidity on different surfaces. It is safe and comfortable to seat on. 

Polish Preparation

POLISH PREPARATION

All grease, marks, dirt and rough surfaces on the plywood top and stainless steel frames must be cleaned before heading to next steps.

Wax & Grease Remover will remove all grease, sticky tape marks and permanent texture marks easily on the stainless steel frames. However, it is not able to remove blue marks around the welded joins. These marks appeared on the stainless steel surface due to high temperature during welding. Sponge is excellent to clear all those marks. 

The plywood top is sanded smoothly on both surfaces and all edges.

3 coats of oil based exterior varnish (British Paints) will be applied to the plywood seat. 

The first coat dried out quickly. But the 2nd and 3rd coats take almost 3 hours to dry

Stool Constructions

12 mm D x 1.6 mm W/T stainless steel tubes can be purchased at:

Design Efex Australia Pty Ltd

14 Chingford St. Fairfield VIC 3078

One of the most difficult job to work on my design is how to bend stainless tubes. To do so, a 25mm plywood template was made in the workshop (by Andrew). The radius of the template is a bit smaller than the top seat radius, it allows the tube to spring back after bending. Then, tubes are cut with a length that is longer than needed just in case it is shortened after bending. 

Results: The tubes are not perfectly shaped because they are bent manually. Rubber hammer is used to adjust the tubes so that they could fit the top seat.

Bending and drilling 3 mm stainless steel sheet are not easy either. Before drilling holes on 4 small plates they are carefully measured and marked to fit the holes of the top seat , they are punched on the surface to allow the drill to go through.

Drill must be sharp and powerful to get the job done

Curved tubes and perforated plates are welded at:

AG Steel Works Pty Ltd

166 Grange Rd Fairfield VIC 3078

Adjustable spanners are used to bend little brackets.
Trying brackets on frames to see if they need to be adjusted

Installing parts together by using correct spanner and and Hex key

UNFINISHED STOOL

When all parts are correctly assembled it is strong and rigid on different surfaces

Next steps will be polishing the plywood top and frames

It is better to have a wide range of tools handy if work at home

Stool

Technical Drawings

EXPLODED VIEW

TECHNICAL DRAWINGS

PARTS DETAILS

Concept Development