ultimate craftsman saw test

A couple weeks ago, however, I picked up a few large hunks of aluminum from Boeing surplus, and, on closer inspection, noticed that they were cut with some sort of a circular blade. The finish of the cut was excellent, with no part deviating probably even 5 thou from any other part. But the marks suggested that it was not fly-cut, or cut with a bandsaw. Instead, they seemed to suggest that it was cut with some sort of a large circular blade, probably well over a foot in diameter. I was not surprised -- Boeing has plenty of machines that are larger than my whole garage, and cost more that an average man's life savings. But I remembered that observation.

A week or so later, I came across this extremely helpful thread of yahoo taigtools newsgroup. After following some of the links posted there, I came to several revelatons, for the lack of a better word. First, I found out that it does not take much force to cut through metal with a circular blade. Second, you do not need to ensure constant feed - chatter is either not a huge issue, or can be compensated for somehow. Third, it seemed that you do not need to hold the blade and the workpiece perfectly aligned at all times. Yes, of course that helps, but that's not easy to do unless you have a dedicated machine, like a power bandsaw with some sort of a feed mechanism. People seem to have been using simple handheld battery-powered circular saws to cut through some serious stuff, including rebar!

That still was not enough for me to connect the dots. This, too, was merely an observation. The other day, however, I got a few Christmas gifts from my wife, including a screwless vise. It came without a clamping kit, so I needed to make some clamping blocks. After dreading the prospect of hack-sawing a large Boeing surplus hunk of aluminum and even contemplating just cutting it with a long 0.25" endmill on my mill, I finally turned my brain on, connected the dots, and realized that my small cheap craftsman table saw might be up to the task.

I must say that the results exceeded all expectations! I did not (and could not) adjust the RPM to match the recommended SFM for aluminum. I used an old carbide-tipped wood-cutting blade with several broken tips. No lubrication was used, and I fed the aluminum by hand, as steadily as I could. The saw cuts through 1" thick 7075 Aluminum like butter. I am not sure how fast, but it seemed that I could cut about 1 linear inch of material in 5-10 seconds! No noticeable chip welding was observed. I did not notice any serious chatter either. It is possible that I simply did not notice because I have no experience with cutters like that, but nothing felt, or sounded wrong, and there were no new broken carbide tips, which is a good sign. The chips were pretty nice and thick. I did not measure their thickness, so I do not know whether I was feeding the stock at a good rate. I simply listened to the motor, and tried not to feed the material so fast that it would bog down.

The cut was not nearly as smooth as the Boeing surplus cuts, but that was easily resolved by fly-cutting the pieces. I no longer dread cutting my stock, at least aluminum. I might want to try steel next, but I want to figure out if I want to use lubricant, and whether that would be detrimental to the carbide tips. I am also a little scared, to tell you the truth. I've seen those carbide tips fly, and I caught a few with my chest. Not a pleasant experience. I want to make sure I know what I am doing, that my hands and other parts of the body are not in line with the blade plane, if possible, and also have some contigency plans in case something goes wrong. Somehow I have more respect for steel, and for the fragility of carbide when it hits steel.