AndyH
10 kW
In the interest of science (or possibly just the need to take a perfectly good device apart) I present the following look inside a new screw-terminal Headway cell.
The cell can is rolled-over the end and no match for a pneumatic cut-off wheel. There's a plastic seal around the end cap that continues into the cell. The cap is a composite of a stamped steel outer layer and a glued and spot-welded aluminum plate. The steel is 1.5mm/.060"; the aluminum is .60mm/.024" thick.
View attachment cap_bottom.jpg
The four spot welds on the 'dome' of the aluminum plate fasten to the aluminum layer inside the cell.
The 6x1mm threads are cut into the stamped end plate. There's 4.5mm of thread depth, compared with 4.75mm of a 6mm nut. More than 1/2 of the thread depth is in the 'tube' formed with the hole was stamped.
Here's a view of the cell when the cap is removed. The visible seal is what remains when the 'U' channel portion is cut when removing the lip on the outer can. And what a wonderful alkaline smell! The four spot welds mate with those on the bottom of the end cap.
Lifting the aluminum disk reveals the thin aluminum straps spot welded on each end.
Removing the seal, spacers, and next aluminum layer exposes the aluminum foil straps that extend into the rolled cell.
Next project...find out what's under the epoxy on the other end.
The cell can is rolled-over the end and no match for a pneumatic cut-off wheel. There's a plastic seal around the end cap that continues into the cell. The cap is a composite of a stamped steel outer layer and a glued and spot-welded aluminum plate. The steel is 1.5mm/.060"; the aluminum is .60mm/.024" thick.
View attachment cap_bottom.jpg
The four spot welds on the 'dome' of the aluminum plate fasten to the aluminum layer inside the cell.
The 6x1mm threads are cut into the stamped end plate. There's 4.5mm of thread depth, compared with 4.75mm of a 6mm nut. More than 1/2 of the thread depth is in the 'tube' formed with the hole was stamped.
Here's a view of the cell when the cap is removed. The visible seal is what remains when the 'U' channel portion is cut when removing the lip on the outer can. And what a wonderful alkaline smell! The four spot welds mate with those on the bottom of the end cap.
Lifting the aluminum disk reveals the thin aluminum straps spot welded on each end.
Removing the seal, spacers, and next aluminum layer exposes the aluminum foil straps that extend into the rolled cell.
Next project...find out what's under the epoxy on the other end.
