I am looking for creative suggestions to cutting aluminum. I do not have a mill, and the prospects of getting one in the near future are non-existant. I have to therefore use other more creative methods. I am primarily interested in cutting off lengths of 2 types of aluminum extrusions, the 1st being square 10mm section in a length of about
60mm, and the 2nd being rectangular 10mm x 80mm in a length of about 150mm. I would like to make the cuts square and perpendicular, holding the length and perpendicularity to .001 inch and with good surface finish.I use a technique on the 1st type that is quite effective. Using a hacksaw and the sides of an old vise as a guide, I rought cut the material to a couple hundredths of an inch of size. Then I use a file on the ends to clean up the cuts. Then I put the metal in a vise, the part being aligned vertically, and place the vice on my drill press. Then using a circular abrasive disc (like the black+decker variety,
120 grit), and using very light "taps", I clean up the ends. Once the ends each have uniform "machining" marks on them, I measure with calipers, calculate how much needs to come off, and repeat the process using the circular disc. I have a good idea of the number of tap/cuts are needed to bring the part down a particular distance, and the process all-in-all is pretty well-defined. I can finish the part in a reasonable amount of time (for the process that I am using - say 20-30 minutes) and the finish vaguely resembles that of one which was fly-cut.Now the problem. With the smaller part, and a light tapping touch, the circular disc does not flex in a considerable manner. When I try to use this approach on the bigger piece, there is flex, "stiction", and general uneven cutting. Therefore, the piece does not clean up uniformly. Also, having a piece clamped 1.5 inches or so and then extending upward out of a vise some 4.5 inches causes a good deal of vibration which further degrades any finish that I might obtain. I am trying to think of a way to achieve similar results (as the smaller piece) in this larger piece using some of the more common workshop tools like a drill, drill press, files, belt sanders, dremel, etc. Short of marking the piece up with prussian blue and then scraping or dremel'ing it's perpendicular edge and then uniformly bringing this perpendicular edge to dimension (and I might get 1 part an evening done, ugh), I see no decent creative solution. So I am hoping someone has a good idea that I can try. Thanks in advance.