Anybody have any tips for how NOT to break #80 drill bits? I use these to drill holes for biplane rigging and always go through 3 or 4 bits on each airplane.
Are there differences in durability depending on the different composition of the bit? For example, is carbon steel better?
Lee
taking it slow and keeping it strait work for me. when i slam into it, i break blades. keep the speed up, to.
Use a pin vise to rotate the bit with your fingers, and chuck the bit to as short a length as possible to get the job done. The longer the working length of the bit, the more likely you are to flex and break it.
Lee, buy the cheapest "made in lower slobovia" bits you can find. Bits made of high speed steel or high carbon steel while lasting better for drilling metals are a lot more prone to breakage. Drilling plastic isn't very demanding and a cheap more flexible drill bit will do just fine. The suggestion to use a pin vise is right on. HTH Pete
I have to replace my sets every so often. However, Model Expo makes cheap replacements, each size, four or five bits per container. I stock up on #60, 65, 70, and 75 with these containers. Then I usually have one of those sizes. When my regular set gets TOO sparse, it is time to replace the whole set, but if I do not need an EXACT size one of those cheapies may do. I do bust them a lot, but since I have several of each, it takes awhile.
I also try to keep the length sticking out of the chuck the minimum that will do that particular job. Too much sticking out of my pin vise and they flex easily, then break. As long as I can get the chuck up close to the piece I am drilling, I mount it so it only sticks out a length equal to the depth of the hole I need, or a little more than the thickness of the material. That makes it a little hard sometimes to see exactly where I am starting the hole, but I do the best I can.
leeroi wrote: : Anybody have any tips for how NOT to break #80 drill bits? I use these : to drill holes for biplane rigging and always go through 3 or 4 bits on : each airplane. : I found that the pin vice has more to do with broken bits than the bits themselves. If the pin vice doesn't hold the drill very close to center, then the drill will tend to wobble when you rotate the vice, which will cause it to break.
I second the Starrett recomendation - I break very few drills with the Starrett pin vices that I have, because they hold the drill very close to center. The rest of the pin vices I had range from not hardly to sorta close, and broke drills in proportion to how off center they were.
Bruce
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