Finally the demanding metal parts have been finished and ready for dispatch, they are perfectly finished finally. See the drawing below, it is kind of bending parts, the

bending angle is very precise, also the 80mm dimension is precise too(for bending part). And the tight tolerance are not the thing to make the parts most difficult, what make this parts difficult to make is quantity, each size only need one piece, Can you believe that? it make the most difficult to make. Because we cannot make a Jig or tooling, it is too expensive. What We have to do is to prepare a few more pieces materials and try bending, and select good one. To drilling hole is also a bit difficult too, because holes are a little difficult to be positioned. We have to make smart tool to mark-off the holes. Finally we finished all the parts perfectly.