Bits Spin in Hand Drills

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warmstrong1955
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Re: Bits Spin in Hand Drills

Post by warmstrong1955 »

My Makita came with a keyless, and I never had a problem with it for 4 or 56 years. When it did, it got worse fast, so I bought a new one, one of the higher priced Jacobs. That fixed it. It has seen a lot of duty.....I just installed it's third set of brushes, same as my 14.4 Volt 3/8" Makita.
Some keyed chucks are garbage. The one that came on my Craftsman, a low dollar substitute for a Milwaukee Hole Hog, was garbage. Wouldn't tighten if you used all 3 holes 47 times.
Replaced it with a good Jacobs key type too. I like the keyless for 'household' work, or timber, but for metalworking, keyed with ball bearings are the way to go.
I don't think I own any drills that still have the original chuck.
And what Harold said.....my Dad taught me to use all three holes...and keep going around until they didn't turn anymore. Still a habit of mine, with any keyed chuck.

Bill
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John Hasler
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Re: Bits Spin in Hand Drills

Post by John Hasler »

Bill writes:
> I don't think I own any drills that still have the original chuck.

The fifty or sixty year old half inch "hand" drill that I inherited does. It doesn't ever slip. It will break your wrist if you aren't careful, though: I think it has an honest 1/2 hp motor in it. It really should be called a transportable two-man drill. It is not to be used without the pipe extension handle, and even then you need to make sure the extension can't hit anything fragile (like your shins) if it gets away.
JackF
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Re: Bits Spin in Hand Drills

Post by JackF »

Try the 3 hole tighten. I learned that from a mill wright years ago. I challenged him on the procedure. He simply said OK, tighten on one hole as hard as you can, then see if you can tighten the other 2 any more. I was red faced as the other 2 did tighten more. :oops: I learned that more than 40 years ago.

Just a little side note; the mill wright worked at San Jose Steel and was the first heavyweight arm wrestling champ on ABCs Wide World of sports.


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Downwindtracker2
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Re: Bits Spin in Hand Drills

Post by Downwindtracker2 »

Seriously, the tighten all three holes doesn't make any sense. Except that you have a lateral pressure on the center of the chuck, picking up the chucks slack.

I find the keyless ratcheting chuck on my DeWalt 3/8" cordless works pretty good.
A man of foolish pursuits, '91 BusyBee DF1224g lathe,'01 Advance RF-45 mill/drill,'68 Delta Toolmaker surface grinder,Miller250 mig,'83 8" Baldor grinder, plus sawdustmakers
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warmstrong1955
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Re: Bits Spin in Hand Drills

Post by warmstrong1955 »

Downwindtracker2 wrote:Seriously, the tighten all three holes doesn't make any sense. Except that you have a lateral pressure on the center of the chuck, picking up the chucks slack.
I suggest you try it. It makes perfect sense.
I can always get a little more movement, when I go to the second hole, and usually a bit more when I go to the third. Depends on the chuck. Has to do with friction, and how the load between the surfaces is distributed. Think about what happens as you exert more force on the chuck key....think all the components remain on the same planes with each other?
It is what I do with all keyed chucks, and it is a habit.
And a good habit.

Bill
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BadDog
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Re: Bits Spin in Hand Drills

Post by BadDog »

Yes, it's that slack that makes it make sense. When you tighten on one hole, everything starts to bind up relative to that force until it is impractical to tighten further. Moving to another hole applies force in a new direction, releasing some of that bind, and tightening a bit more. If you don't take out that slack, then the forces of drilling will release that bound slack and the drill bit is no longer as tight as you thought when you started.

Depending on chuck (and bit) condition, size, and hand strength variables, you may get more or less with each increment around the chuck.
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Harold_V
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Re: Bits Spin in Hand Drills

Post by Harold_V »

Downwindtracker2 wrote:Seriously, the tighten all three holes doesn't make any sense.
Yes, it does make sense, at least to those of us who understand what's going on. Don't judge until you've tried.
I have yet to encounter the chuck that didn't benefit by the extra tightening. It doesn't just make a difference---it makes a BIG difference.

H
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spro
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Re: Bits Spin in Hand Drills

Post by spro »

This relates to lathe scroll chucks also. There is the certain one which is the "last word" . The others are tightened lightly before the master jaw because it cannot take all that and remain the last word.
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neanderman
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Re: Bits Spin in Hand Drills

Post by neanderman »

spro wrote:This relates to lathe scroll chucks also. There is the certain one which is the "last word".
Can one assume the "last word" is the #3? Or the reverse?
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Harold_V
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Re: Bits Spin in Hand Drills

Post by Harold_V »

Depends on the chuck. Some have but one key hole, while others have more. Three is typical, with some coming marked from the factory, so the hole with the greatest precision is to be used. Much like using soft jaws.

On that subject, I can think of no better way for a Doubting Thomas to learn the lesson than to try using soft jaws. Use the wrong hole and tell me what happens.

H
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earlgo
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Re: Bits Spin in Hand Drills

Post by earlgo »

My background is Mechanical Engineering and I had been in R&D and Hydraulic Calculations for nearly 16 years before I had a job at a real manufacturing plant as a manufacturing engineer. That was the first time I remember seeing a lathe operator tighten a drill chuck with all 3 holes. At the time I thought that he was going to break the chuck. Odd thought, but my experience previously, including at the Colorado School of Trades, was to use one hole. I have never seen the '3 hole' method mentioned in any book on machining including the Machinery's Handbook.
I have some bits with shanks so chewed up that one wonders if they were turned with a pair of water pump pliers. Eventually I learned to do it right, and haven't spun a drill in a couple of weeks or so. That was because the Dewalt drill chuck was set on '3' when the drill was tightened in place.
Oh, and the hex shanked drills work great until the staking that holds the drill to the shank comes loose. Happened on a cheapo set but not the DeWalt set, yet. I suppose brazing the drill into the shank is cost prohibitive.
Excuse the ramble.
--earlgo
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NP317
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Re: Bits Spin in Hand Drills

Post by NP317 »

Harold_V wrote:
Downwindtracker2 wrote:Seriously, the tighten all three holes doesn't make any sense.
Yes, it does make sense, at least to those of us who understand what's going on. Don't judge until you've tried.
I have yet to encounter the chuck that didn't benefit by the extra tightening. It doesn't just make a difference---it makes a BIG difference.

H
I was taught by a machinist to tighten drill chucks using all three holes, and have practiced that for decades of machining.
It works.
~RN
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