Dad and I built a new, longer bending brake from scratch over the last week, using the "Dave's Cheap Bending Brake" plans found on the web. This was quite a little project in itself, but we got R done.
Tonight Mom and Dad came over for dinner, and Dad and I put the bending brake to the task of bending its first part: the rudder skin.
We used the Olfa knife to cut a piece of .025" sheet from a 12 foot long piece, right off the rack in the garage. After cutting the piece to size, we did a few test bends on the brake with scrap sheet, to get a sense of where to place the bend mark, and where the mark ends up in the bend. Once we were satisfied with that, we started measuring and marking the rudder skin.
Two of the bends are very acute angles - Dave (of Dave's cheap bending brake fame) shows a picture in his plans of him using another piece of angle steel clamped to the pivoting portion to get more bend in the part. We didn't have any extra, so we started by using a piece of 2x4 on scrap to effect the bend. The 2x4 ended up creasing the upper part of the sheet as the sheet pressed against the clamping angle. Dad suggested we use a thinner piece to avoid that problem. We switched to a 1x2, and it worked beautifully. We got three very pretty bends in the rudder skin, all with what looks to be a spot-on radius. And it went pretty quickly.
2.5 hours - Dad
2.5 hours - Me