4 ms·

BTW: Making small spade bits is completely doable if you have a lathe, stone, and screwdriver sharpening jig. I've done it myself down to 0.5mm but that small

BTW: Making small spade bits is completely doable if you have a lathe, stone, and screwdriver sharpening jig. I've done it myself down to 0.5mm but that smallest one was just an exercise...if I valued my time, it was a $100 bit of much lower quality than what's easiy bought for MUCH less.

mauvehaus 4y ago
For anybody who wants to try this themselves, or wants to sharpen drill bits generally, getting the concentricity of the point and the shank accurate is absolutely key. For normal-sized drills, at best you're going to drill an oversized (and likely tapered) hole. When you get into the smaller sizes, you're going to break bits left and right. For normal-sized drills an everyday drill sharpening gauge should do the trick. That'll stop being useful long before you get down to 0.5mm. If you're drilling wood or some other soft material, and you've got bar stock of the right diameter around that isn't hardened (i.e. a nail), you can sometimes get away with clipping the end of the nail off with a pair of diagonal cutters and peck drilling. You have to peck because the shank fills the hole so there's no way to clear the chips.
- 2ICofafireteam 4y ago
  If the point angle looks symmetrical and the flute lengths look the same, then it's usually fine/close enough for most fab work.
LeifCarrotson 4y ago
Clickspring has an excellent video on simple shop-made drills: https://www.youtube.com/watch?v=N1aj_3tlQhU https://www.youtube.com/watch?v=N1aj_3tlQhU You don't need the lathe (though he uses one to rotate it for easy sanding, a drill chuck would work just as well), merely a stone, a torch, and some stock of appropriate diameter...you only need the lathe if you're starting with a shapeless chunk, and this isn't the stone age anymore! https://www.mcmaster.com/metals/hardened-undersized-high-speed-m2-tool-steel-rods-9/ https://www.mcmaster.com/metals/hardened-undersized-high-spe...
- 2ICofafireteam 4y ago
  I will check it out; thanks. I've seen some of his videos and he does lovely work.

mauvehaus 4y ago

For anybody who wants to try this themselves, or wants to sharpen drill bits generally, getting the concentricity of the point and the shank accurate is absolutely key. For normal-sized drills, at best you're going to drill an oversized (and likely tapered) hole. When you get into the smaller sizes, you're going to break bits left and right. For normal-sized drills an everyday drill sharpening gauge should do the trick. That'll stop being useful long before you get down to 0.5mm. If you're drilling wood or some other soft material, and you've got bar stock of the right diameter around that isn't hardened (i.e. a nail), you can sometimes get away with clipping the end of the nail off with a pair of diagonal cutters and peck drilling. You have to peck because the shank fills the hole so there's no way to clear the chips.

2ICofafireteam 4y ago
If the point angle looks symmetrical and the flute lengths look the same, then it's usually fine/close enough for most fab work.

LeifCarrotson 4y ago

Clickspring has an excellent video on simple shop-made drills: https://www.youtube.com/watch?v=N1aj_3tlQhU https://www.youtube.com/watch?v=N1aj_3tlQhU You don't need the lathe (though he uses one to rotate it for easy sanding, a drill chuck would work just as well), merely a stone, a torch, and some stock of appropriate diameter...you only need the lathe if you're starting with a shapeless chunk, and this isn't the stone age anymore! https://www.mcmaster.com/metals/hardened-undersized-high-speed-m2-tool-steel-rods-9/ https://www.mcmaster.com/metals/hardened-undersized-high-spe...

2ICofafireteam 4y ago
I will check it out; thanks. I've seen some of his videos and he does lovely work.