I got back quite late on Sunday from the 10km run so didn’t get a chance to work on the case. Yesterday I trialled the bending process using the MDF sandwich method, as per my previous post, to bend the test sheet. The first issue I had to resolve was getting the bend point right. As noted on http://forums.bit-tech.net/showthread.php?t=127450 , you have to overlap the lengths to accommodate for bend radius and material thickness, ref.: As my Aluminium is 2mm thk, I offset/overlapped the two measurements by 2mm + 0.5mm for a bit of play (for the stretching/radius in the bend). The bending method worked ok, near enough 90deg. The lengths however were slightly longer than aimed for. Doh , stupid here forgot that this was the radius and therefore the overlap would be 2mm either side of the bend line. The overlap should therefore be 4.5mm (adding the 0.5mm contingency for stretching/bending). With the new lengths marked on the new tester sheet, the result was near perfect. Both lengths, either side of the bend, were as required (10mm for the tester sheet) give or take 0.1 mm. The main sheet of aluminium was marked up with the offsets. And clamped into the MDF sandwich ready for bending. After aligning the new mark-up I began to hammer the sheet around the bend (with a soft piece of wood to absorb the hammer blows and to evenly apply the bending across the entire length of the sheet). This did not go to plan . As the tester sheet was a short length, it was pretty easy to bend. The main sheet however was a lot longer and therefore not as easy to bend. The result was that the bend was unevenly applied and created a ripple in the sheet. The clamps were not tight enough to hold everything in place and resulted in the sheet shifting and the bend being off the marked line. I straitened the sheet out again with gentle persuasion from the hammer and tried again, this time heating the metal. It still would not bend easily and evenly, and again the clamps loosened to offset the bend from the intended line. So, back to the drawing board . .