A Boring Question
May 28th, 2009Also: Swarf Disposal
I was about to go study machining and fool with the lathe when I realized I had questions. Answer if you can.
What’s the best way to clean up swarf? The shop-vac doesn’t seem to have the juice to suck oily steel up efficiently. Maybe I should get a dustpan and a hand broom. Funny how the books and videos don’t tell you what to do after you make the mess.
I ordered a boring bar. But it’s big. How small a hole should you expect to be able to bore with a lathe? Do you always use boring bars, or is there a certain point where you give up and use a drill followed by a reamer?
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Someone wanted to see the little bit of turning I did yesterday.
May 28th, 2009 at 10:20 AM
I have limited production experience, but in my college machining classes we mounted a drill bit in a drill chuck in the tail stock and spun the workpiece as we advanced the bit.
Most of our work with the boring bar involved working cleaning out a casting or forging which had a preformed larger diameter rough hole to machine.
Generally the process is to drill a large enough hole to accommodate the boaring bar and proceed from there.
I did manage to successfully cut an internal ACME thread in a jack screw casting using the power feed and a boaring bar/thread cutter but it was nerve racking.
Regarding the bar size, you’re gonna end up wanting several diameters/lengths because of the need to process different diameter and depth holes i.e. larger stiffer bars for deeper holes.
(I don’t claim to be a machinist but I have designed a great number of machined parts through the years and my machining and welding classes in my second college career have served me well…I wish you could find a place like Southern Polytech in the Atlanta Suburbs to take a class designed for engineers and they’d get you up the learning curve real fast.)
May 28th, 2009 at 10:37 AM
For ferrous metals, use a rolling magnet sweeper http://www.amazon.com/Crawford-Lehigh-SM16-12-16-Inch-Rolling-Magnetic/dp/B0009WG65C for other stuff, use a broom.
May 28th, 2009 at 10:45 AM
For smaller holes, just get a drill chuck mounted on a taper that fits your tailstock. and use a good sharp drill bit This works fine up to about 1/2″ holes or so. If the stock you’re machining is whippy or flexible, you may need to use the steady rest to hold everything in alignment.
May 28th, 2009 at 12:56 PM
In my high-school machining class (overseen by a stern, recently laid-off Japanese foreman) we wiped things down with our 12″ medium-bristle brush. Wipe the top of the machine for fine bits, then sweep out the trough, then slowly clean out all those little cracks for tiny bits left over. Then we swept the various metal bits – which are now on the floor – into a dustpan.
The key was the brush with 3″ bristles: just enough lube from the machine in them to keep the bristles soft and stick to the metal shavings…. but not so much as to get the metal-machine-being-cleaned all gummy.
May 28th, 2009 at 2:47 PM
Don’t you have a blowgun for that giant air compressor? Blow it on the floor and try the Shop vac or floor broom then. Use your face shield.
May 28th, 2009 at 5:38 PM
You will need several boring bars, of different lengths and diameters. Use the biggest you can stick in the hole without rubbing. Drilling works fine for many things. Do that, if it is sufficient. Drilled holes, however, are not necessarily straight. Nor are reamed holes. Reamers usually follow the hole, and are flexible. Use reamers to clean up a surface to a standard dimension, over and under.
Use a boring bar when the size is odd, large, or when the hole absolutely positively has to be concentric with the spindle. Boring is just turning the inside diameter, and you already know that turning the outside diameter give concentricity with the spindle. Boring also gives you a very nice surface finish.
May 28th, 2009 at 7:48 PM
Be very, very careful about blowing chips off your lathe as RipRip suggested, it’s easy to blow them into places where you don’t want them. A brush and/or vacuum cleaner is the way to go.