...The 3 main problems are:
1. It takes forever, is very draining and there is no satisfaction in working. Some said that they found filing therapeutic and enjoyable, I beg to differ. :grumpy:
2. The file flexes, that is why my grind line is "S" shaped on one side.
3. My grind is too shallow to have crisp grind lines, which I love the looks of.
I cut, shaped and drilled two blanks out of leaf spring (5mm) on Sunday. I also cut the bevels of one of the blanks with the help of an angle grinder + jig/files. It took me about 1h30' to cut those bevels (4"+ blades). You are about to build yourself a KMG but until then, maybe it is worth giving the angle grinder a try as I suggested you long ago. You are almost finished on this one, so do it with the next.
If you are having problems with the grind line it could be for a lot of different reasons like the stock not being perfectly flat, the stock flexing, your jig flexing, etc. I guess that the file flexing is not one of them. If there is some absolutely rigid steel in your shop... ¡then it is on your files!
If you are not happy with the grind lines, instead of a saber grind, make them full flats. It helps covering imperfections.
Mikel