Drill Chucks

[david pierce]

I look at drill chucks a certain way that pertain to how I use them. In my personal view a keyless chuck is designed to spin. I see a slight trade off with a key chuck which is designed to grip tightly. A quality keyless chuck can spin faster with less runout than a quality key type chuck. The small Albrecht 0-1.5 chuck is rated to spin at 50,000 rpms and has almost no runout. It holds very small diameter drill bits perfectly and there is no key type chuck that can equal this. Any chuck I put in a lathe tailstock is always a key type chuck because it doesn’t spin and I want the most gripping power I can get. Since the chuck does not spin I don’t see runout as a major issue in this application. In a drill press or milling machine I use keyless chucks for the small drill bits and key type chucks for the large drill bits. For tools with hard shanks such as carbide drills and small endmill cutters (carbide or steel) I always use collets.
david

[arutha]

David,
I would like to point out to the newer guys and maybe some of the older guys that don’t take the companies word for chuck accuracy. Myself and Daryn have had cheap chucks with next to no runout and expensive chucks way out of their expected tolerence. Don’t take it for granted they are good, if ever you buy a new drill chuck or any kind of chuck for that matter, it is worth putting in a test bar and checking it with a dial gauge. It might seem like a lot of hassle but you will turn out much better work if you take the time!
Paul.

[david pierce]

Paul,
This becomes expecially true with extremely small diameter drill bits. If the chuck is out .001 inches with a 1/2 inch drill bit then the runout is only 2/10 of 1% of the drill diameter. This would not be particularly noticeable and have very little effect on the hole or the drill bit. On the other hand if the chuck is out .001 inches and the drill bit is .010 inches in diameter, the runout would be 10% of the drill diameter. This could cause problems and possible drill breakage in the hole.
david

[chris mabbott]

Has anyone tried to disassemble either type of chuck for servicing? I’ve not tried it with a Jacobs ball bearing chuck, but I am wondering about it :ugeek:

[arutha]

Not me Chris but it is something I would like to do, maybe someone with experience of this could enlighten us?
Paul.

[arutha]

https://www.youtube.com/watch?v=97jlPVPn19Q
Good old youtube

[Bob Tascione]

Good video. Nice find Paul!
Thanks
Bob

[chris mabbott]

That’s a great one Paul, perfect, just what I was looking for, thanks for posting, I love pineknott I could listen to him talking all day Ya’ll put them thar jaws waay up now and give it a lil ole beatNn with that thar hammer… Classic

[chris mabbott]

After watchin me that thar vid got me a hankerin to be pullin that chucka mine apart, I’m also a fixin to be a practicing my southern accent on these here banditos, might sound pretty darn strange but I’m gonna be doin it, a might slow like

I love the South..

[arutha]

Lol Chris, I can imagine you sitting there with your corn pipe and straw hat tearing that chuck down

I will be doing my own chucks once I can get back to work. My back is stuffed at the moment hence all my activity on the forum, you guys are the only thing keeping me sane!

[chris mabbott]

@Arutha wrote:

you guys are the only thing keeping me sane!

Now Paul, that is a scary thang, you’re turning to us for sanity 😆

[daryn]

David, that’s incorrect information, most modern keyless chucks are designed to tighten in use and are therefore less likely to slip, if you don’t have a weak wrist that is. . .

[daryn]

That’s the reason albriect recommend not to use reduced shank drills in thier keyless chucks, they’ll self tighten so much with the extra torque that you’ll not get them undone again

[david pierce]

Daryn,
No, that is not incorrect information. I reread my post and also your mean spirited generalized comment implying that if a drill bit slips it is because I have a “weak wrist”. As a point of fact I too read the Albrecht sales brochures over 30 years ago and fully understand the theory of how keyless chucks work. I have also designed various chucks for use in the conveyor ovens we manufactured that used both 2 and 3 jaws. A couple of my machines were in the Magneti-Morelli (old Lucas plant) in Birmingham England and if they are still there you can drive over to the factory and take a look at the chucks. After 40+ years associated with machine shops and machine shop operations I have reached my own conclusions about tooling and how it performs under actual shop conditions. I have seen drill bits slip in both key type and keyless chucks and have formed certain opinions about the purpose of their design and aplication. I still have a small machine shop and own a range of both Key and keyless chucks. My Albrecht chucks range from 15J0 – CP130 – R8 and because I have always used them for what I felt was their intended purpose, they are still able to hold their precision and low runout. When I need to take a heavy torque load cut with a larger size drill bit I will us my Jacob Ball Bearing Super Chuck and not my Albrecht CP139 – R8. In spite of what the Albrecht sales brochures say I feel that keyless chucks are better suited for high precision, high RPM applications where they are not used under abusive conditions. If a bit slips in a Ball Bearing Super Chuck you can simply retighten it by applying a little more pressure on the chuck key. These chucks are designed to take that kind of service. You may be able to obtain the same result by tightening a keyless chuck with a couple of pipe wrenches but I am not going to do that with my chucks. I have purchased used Albrecht chucks off of Ebay that were abused in this manner and they no longer run true. For the smaller size drill bits (example #80) the Albrecht keyless chucks are unparalled. The torque load applied to the chuck jaws is also much lower so the drill bit is more likely to break than slip.
david

[daryn]

A case of separation due to a common language I think,
I was not meaning you personally having a weak wrist,
I I definitely wouldn’t consider using a pipe wrench on a precision piece of equipment of any description,
Having drill slippage is not going to happen if tools are used correctly, it’s either going to be because someone has not tightened it correctly, hence the weak wrist comment, or the feed rate is too much or the drill is sharpened incorrectly for the material being drilled,
I have no idea what relevance the rest of your comment has, please explain?
And yes, advising people to graunch down on keyed chuck rather than use it correctly I would consider “wrong information”

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