Read up on the ways to hurt yourself with a drill press ! is is 95% of any metal working job and is bound to take 90% of the time. I'm not saying my style is perfect, but I've learned a lot over the last few years.įirst find a way to clamp your workpiece securely without damage to the part or importantly you. I try to start with light pressure and build up pressure and speed until I see that happening. In terms of speed and pressure, I've been doing most of my stuff by hand, so I don't know what speed and pressure I'm using - but my friend pointed out what others here have stated, that you should aim to be getting spirals of metal being cut off. That has made so much difference to my work. When one of my bits stops cutting, I put it aside and sharpen it before using it again. If your final bit is seriously large, then you might need a fairly large pilot hole, in which case you should choose a smaller bit to make a pilot hole for the pilot hole :) The smaller bit will have a much smaller flat chisel end, and so will be scraping less metal around, allowing you to cut more.ĭescribing the details of how to sharpen a standard HSS bit with a bench grinder is beyond my skills here, but it's well worth learning. If you need to use a large bit for the final hole, then start with a bit that is just a little bit wider than the flat chisel end of your large bit, to drill a pilot hole. This doesn't cut, just scrapes the metal aside. Right at the tip of a large bit, you'll see that it does not go to a sharp point - it's more of a flat chisel. Then a friend whose dad had been a tool maker taught me how to sharpen HSS bits with a bench grinder, and pointed out the different aspects. I feel your pain at starting small and going up in size gradually and being frustrated that it's dulling the outer edge of the bit. Some excellent answers there, but I just want to give a bit more detail and explanation of bit diameters and pilot holes. (yes, all the drill press' power is being turned into heat, but the long chips like spaghetti noodles are carrying it away). You're banging holes out very fast, using little oil, the bits aren't dulling and aren't even getting warm. Once you get it dialed in, it's sheer pleasure. Harper's rule of cutting metal: If you're not cutting, you're not cutting. That's why you kept destroying better and better bits, you kept trying to re-drill the same place you'd already work-hardened. But the latter may destroy the properties of the metal. You'll need to find another spot, find another part, switch to waterknife, or do something thermally to remove the work hardening. If you're "not cutting" for even a second, you are "work-hardening" the material. Once you have the drill at the RPM the book actually says for that metal and bit, an attentive operator has a reasonable chance at finding the correct plunge rate/pressure, just by noting what force makes it cut "like butter" vs fail to cut.īut work fast. In drills that translates into RPM (for a drill size) and plunge rate. Machinery's Handbook (or other resource) will have correct feeds & speeds for your material. You're blind guessing.įor any given metal, there is one correct/ideal feed (the depth of cut) and speed (the linear rate of cutter movement through the material). Running my drill press on the lowest setting Masonry bits, and even regular wood drill bits CNC plasma cutter ate it for breakfast, though I would've rather used a waterknife. Seriously though, I had to cut 13 holes (some square to capture carriage bolts) in 50 sheets of metal. After a lot of googling I think the only thing I haven't tried is a tile bit.
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