Questions about twist drills

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earlgo
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Re: Questions about twist drills

Postby earlgo » Tue Jan 10, 2017 12:04 pm

Harold_V wrote: Gunsmiths, using less than great lathes, have (successfully) drilled deep holes for a long time now, thanks to that technology.

True, but the very early guys hammer forge-welded a strip of wrought iron around a long mandrel, straightened the resultant tube, and then using primitive bits, bored the tube to size, and then rifled it, if required. I don't know when the high pressure coolant fed gun drill was perfected, but it was most likely not before the 20th century. (I didn't 'google' it so correct me please.)
--earlgo

atunguyd
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Re: Questions about twist drills

Postby atunguyd » Wed Jan 11, 2017 2:38 pm

Harold, can you please elaborate on your warning earlier in this thread about using the side of the grind wheel and "horsing". I am not familiar with this term horsing and it seems a valuable warning.

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BadDog
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Re: Questions about twist drills

Postby BadDog » Wed Jan 11, 2017 4:01 pm

He's just saying it's ok to use the flat side of the wheel for light relatively gentle work when needed to provide a flat surface not easily achieved working on the circumference of the wheel where most grinding is done. If you get very aggressive using the side of the wheel, or start developing significant grooves, you risk breaking the wheel and causing damage and/or serious injury. It's also worth noting that beyond initial truing, cleaning and refreshing a wheel side should you dull it can also be problematic, so in my shop I use the side both gently and sparingly only as needed.
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SteveHGraham
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Re: Questions about twist drills

Postby SteveHGraham » Wed Jan 11, 2017 4:17 pm

You just have to use common sense with abrasives. Like when I use a Dremel tool to remove calluses from my feet.
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BigDumbDinosaur
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Re: Questions about twist drills

Postby BigDumbDinosaur » Wed Jan 11, 2017 4:46 pm

SteveHGraham wrote:You just have to use common sense with abrasives. Like when I use a Dremel tool to remove calluses from my feet.

Podiatrists use a Dremel-like tool to remove calluses and bunions, except theirs is made from stainless steel and probably costs thousands of dollars, being a medical instrument. :shock: As the old warning goes: trained professional, do not try this at home. :D
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