Fabrication Method
Intro | DIY Build Instructions | Fabrication Method | GEK Licensing
The GEK is easily fabricated at small or large scale using standard sheet steel. The sheet steel is cut into three basic part types: vessel tubes, flange rings, and end plates. These are rolled then snap together for welding. A tab and slot system is used on all parts, thus they self-ji for easy and accurate welding.
Here’s an example of the CAD drawings for the parts to form the hopper, gas cowling, downdraft reactor (nozzle and constriction type) cyclone and swirl burner:
The resulting parts are pictured below. (left to right: hopper, gas cowling, downdraft reactor and insulation tube, cyclone, and swirl burner)
The full set of vessel tubes is cut from one sheet of 4′ x 8′ mild steel (1/16″ thick). A typical three wheel manual roller forms the flat parts into cylinders. All the flanges and end plates are cut from one third of a 4′ x 8′ sheet mild steel (1/8″ thick).
Below is the layout pattern for the 1/16″ and 1/8″ sheets. Note the nesting of “rings within rings” for the flange rings and end plates. The width of a plasma cut is about equal to the 1/16″ vessel tube thickness. Therefore the offset between the outer and inner cut parts corresponds nicely with the outer and inner diameter of the related vessel tube. This layout method minimizes wasted material and cut time, while insuring a perfect “on dimension” fit. The flange rings and end plates also second as the the “jig” to final form the tubes to true round before welding the tube seams.
The ALL Power Labs shop cuts these part with a CNC plasma table that achieves 0.05″ accuracy to the CAD drawings. The parts can also be cut by hand with a handheld plasma torch and a homemade protractor to guide the torch around the circles. For larger production runs, the pieces could be punched, likely also with a reduction in metal thickness. We are using metal that is thicker than necessary as it easier for the end user to weld and modify.
To simplify shipping, the kit is designed so vessel tubes nest inside each other like a “Russian Doll”. Flange rings and end plates similarly bunch into a thin pancake. Total package dimension: 24″ x 17″. The weight is below 150lbs, so it can ship UPS ground, avoiding the hassles of freight shipment. The tube pieces can also be left unrolled and the entire kit shipped as a flat package.
Here are pictures of a fully assembled GEK unit built from scrap tanks and manufactured plates.
All GEKs are assembled and packed-out on location at the ALL Power Labs shop in Berkeley, CA, USA. You can see how we manufacture, stock and ship the GEK in the Fab Shop and Shipping photo gallery.
Detailed instructions for DIY fabricating, assembling and firing the GEK are in the GEK wiki sand box.
