FOUR JAW CHUCK do like it or hate it 4
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chucketn
Senior Citizen
I mainly use a 3 jaw, but have both 4 jaw independent and 4 jaw self centering. When I need them, they are indispensable!
Chuck
Chuck
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I have 4 jaw self centering only.
Suitable to hold centered square rod as well as hexagonal or flat rod.
Suitable to hold centered square rod as well as hexagonal or flat rod.
Cogsy
Well-Known Member
Once I learned to use a 4 jaw independent I used it non-stop for quite a while, but for some reason I changed back to the 3 jaw and I've got too lazy to use the 4 jaw unless I really need to. One of these days it'll go back on and I'll get back into the habit of using it though. I really like being able to re-true my parts after I've un-chucked and re-chucked them.
I have work in shops where the only had 4 jaw chuck, not even collets
I have also seen in other shops where ever lathe had a 3 jaw and 4 jaw was cake with 1/2 dust and chips. Take a hour or two of cleaning just to use the 4 jaw.
My favorite almost ever shop had stories of the machinist trying to use four chuck only have the chuck key fly. :hDe:
When first start use 4 jaw 40 years ago, my father and my self try reading ever book that had. I took less than day for two of us to get first part running. :redface2:
Yesterday it took less than minute to have the shaft chuck and running.;D
Dave
I have also seen in other shops where ever lathe had a 3 jaw and 4 jaw was cake with 1/2 dust and chips. Take a hour or two of cleaning just to use the 4 jaw.
My favorite almost ever shop had stories of the machinist trying to use four chuck only have the chuck key fly. :hDe:
When first start use 4 jaw 40 years ago, my father and my self try reading ever book that had. I took less than day for two of us to get first part running. :redface2:
Yesterday it took less than minute to have the shaft chuck and running.;D
Dave
jj-smith
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Good question,
I like the 4 jaw for the ability to let you offset for a shaft with a crank pin, or drill off center holes in a work piece on a lathe
I think they are as much a part of your regular use in building gizmos, and now lately, miniature engine making as a 3jaw chuck is.
Once you get the hang of centering your work piece, it is a dandy tool to have on your lathe.
I am fitting both an extra 3J and a 4J on my mini RT to have that same versatility and more on my mill, and combined with both machines the possibilities for drilling, shaving, curve cutting and milling are almost limitless.
J.
I like the 4 jaw for the ability to let you offset for a shaft with a crank pin, or drill off center holes in a work piece on a lathe
I think they are as much a part of your regular use in building gizmos, and now lately, miniature engine making as a 3jaw chuck is.
Once you get the hang of centering your work piece, it is a dandy tool to have on your lathe.
I am fitting both an extra 3J and a 4J on my mini RT to have that same versatility and more on my mill, and combined with both machines the possibilities for drilling, shaving, curve cutting and milling are almost limitless.
J.
Unless you are only doing round bar work a 4-jaw independent chuck is pretty much essential, though if not available, there is not much you can't do if you have a face-plate and an angle-plate. A self-centring chuck is merely a huge convenience. And you should use the 4-jaw for rough bar too, to preserve the accuracy of the 3-jaw.
I don't use it much but I'm glad i have one when I need it.
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Use mainly 3 jaw.But 4 jaw is a must have and only use it when i have to
Use it mainly for holding sq and rectangular plt for turning/boring
For example for the eccentric for the beam engine,i mark out on 1/4 brass,
drill and bore and then bandsaw to size and shape.Invaluable.I must note that i am using my 3 jaw a lot less now i have a full set of collets.To turn take out reverse etc and keep concentricity is great
Use it mainly for holding sq and rectangular plt for turning/boring
For example for the eccentric for the beam engine,i mark out on 1/4 brass,
drill and bore and then bandsaw to size and shape.Invaluable.I must note that i am using my 3 jaw a lot less now i have a full set of collets.To turn take out reverse etc and keep concentricity is great
goldstar31
Well-Known Member
The variety of comments is pretty indicative of the depth of knowledge and experience of each poster.
Charles Lamont is absolutely correct in his practice and recommendations. One bought a lathe which had the basics of a a faceplate, a catchplate and a pair of centres- hard and soft. If it was a screwcutting lathe, the cogs arrived as well.
There was none of this three jaw 'blether' and the next accessory was the 4 jaw independent chuck and the first discovery was that it was a damned sight easier to use two keys - and not the supplied one. There was none of this silly excuse for a fancy tool post ' gazira gazinta' and a simple one tool fixing went on the tool post. One stuck a used single safety razor blade between the work and lathe tool tip- and got that right before romping off into outer space with the pissing match gadgets.
Despite the possible comments, that was a wonderful learning platform on which the rest of one's hobby was based.
I still have my home made collets, the book by Sparey had the drawings and a note of 'when you have the basics- and not until' you could move to making a 5cc diesel engine- to his design. There is a serious remark- out of old age and experience. A three jaw chuck is only accurate when new of holding perhaps 5 thous concentricity. If you stick a piece of rough round metal in to it, you are straining and making so called accuracy worse. Again, if work is held by the tips of the jaws you knacker the holding accuracy further. The end result is a wailing letter to the favourite forum of 'how do you correct your balls up?' The answer, despite all the wonderful words, is that you cannot.
End of lesson
Norman
Charles Lamont is absolutely correct in his practice and recommendations. One bought a lathe which had the basics of a a faceplate, a catchplate and a pair of centres- hard and soft. If it was a screwcutting lathe, the cogs arrived as well.
There was none of this three jaw 'blether' and the next accessory was the 4 jaw independent chuck and the first discovery was that it was a damned sight easier to use two keys - and not the supplied one. There was none of this silly excuse for a fancy tool post ' gazira gazinta' and a simple one tool fixing went on the tool post. One stuck a used single safety razor blade between the work and lathe tool tip- and got that right before romping off into outer space with the pissing match gadgets.
Despite the possible comments, that was a wonderful learning platform on which the rest of one's hobby was based.
I still have my home made collets, the book by Sparey had the drawings and a note of 'when you have the basics- and not until' you could move to making a 5cc diesel engine- to his design. There is a serious remark- out of old age and experience. A three jaw chuck is only accurate when new of holding perhaps 5 thous concentricity. If you stick a piece of rough round metal in to it, you are straining and making so called accuracy worse. Again, if work is held by the tips of the jaws you knacker the holding accuracy further. The end result is a wailing letter to the favourite forum of 'how do you correct your balls up?' The answer, despite all the wonderful words, is that you cannot.
End of lesson
Norman
Tin Falcon
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Forrest Addy used to write for home shop Machinist magazine . IIRC it was he in one of his articles that recommended the newbie install a 4 jaw independent chuck and keep it on the lathe for a year before using the 3 jaw chuck.
IMHO a good practice the 4 jaw is one of those tools that if you are not comfortable with it you do not use it or use t much . But unless you use it and practice you do not get comfortable and fast with it. So if you have one clean it up and use it.
Note : The grizzly 9 x 20 lathes come with a euro style 4 jaw that is a bit awkward to use. While I do recommend using it and practice you may go crazy using it for a year. Just a caveat that there are two types of independent 4 jaw chucks.
Tin
IMHO a good practice the 4 jaw is one of those tools that if you are not comfortable with it you do not use it or use t much . But unless you use it and practice you do not get comfortable and fast with it. So if you have one clean it up and use it.
Note : The grizzly 9 x 20 lathes come with a euro style 4 jaw that is a bit awkward to use. While I do recommend using it and practice you may go crazy using it for a year. Just a caveat that there are two types of independent 4 jaw chucks.
Tin
goldstar31
Well-Known Member
Whilst I agree with you and Forrest Addy ( for whom I have great repect) there are 'lots' more independent 4 jaws. I used to have one on the faceplate of a Pools 'Major' which had it not been worn out in War work, I would have kept. It had two lead screws working together and independently and would mechanically drive cross slides and do tapers- by tightenning or loosing handles. Wow, what a toy! Again I have independent 3 and 4 jaw chucks for a baby Enox which belonged to a relative of James Watt. Still got the chucks and the top slide which often move onto my Clarkson and homemade Quorn. Again, I have a scroll chuck which is really for clock and watchmaking and a sort funny one that came with my MJ189( a Unimat clone)
That is a sort of off shoot of a fabricated slotted faceplate with 4 jaws.
I was fiddling the other day about the comments on boring tools and having another look see. I was toying with the catchplate on my Myford with a view to fitting a top slide on it but with intervals for various tools or work. Jack Radford did it earlier. My thoughts were that it would do ball handles if a rotary table was fitted- between it and the chuck.
So we get to rectilinear and curvillinear chucks and doodahs for ornamental turning. Its all in Holzapffel- for free for those who are interested enough.
Norman
aonemarine
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95% of the time I use my 4 jaw independent chuck, it has larger deeper jaws than any of my 3 jaw chucks and I feel most comfortable working with it even though it does take a minute to set up. Most of my 3 jaw chucks have about .005" run out so unless im doing something quick and dirty I use the 4 jaw. Maybe If I had a 3 jaw with only .001" run out I would use it more....
I started use a four jaw after putting dial indicator on the shaft in a three jaw TIR .003. I still use both today but need good TIR its the four jaw
Dave
Dave
goldstar31
Well-Known Member
Setting up? Agreed but with a decent tool room mike from a grinding machine- 2/1oths of a thous can be expected.
I've never felt rich enough to buy a GripTru but I do have a rather nice dial mike from a Boxford grinder. Years ago, I was following Martin Cleeve who bought half a lathe. I bought a scrap one.
Regards
N
I've never felt rich enough to buy a GripTru but I do have a rather nice dial mike from a Boxford grinder. Years ago, I was following Martin Cleeve who bought half a lathe. I bought a scrap one.
Regards
N
rake60
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My lathe is getting old. (So Am I!)
Things start to wear out.
My 3 jaw chuck runs out about .002" now.
If I'm making a part that needs to be flipped for machining on the other end the 4 jaw goes on
for the second setup so the part can be indicated in as close as possible.
If a part can be made in one setup and parted off there's no way I'd bother indicating in a 4 jaw
setup.
Getting older makes you lazy too!!!!
Rick
Things start to wear out.
My 3 jaw chuck runs out about .002" now.
If I'm making a part that needs to be flipped for machining on the other end the 4 jaw goes on
for the second setup so the part can be indicated in as close as possible.
If a part can be made in one setup and parted off there's no way I'd bother indicating in a 4 jaw
setup.
Getting older makes you lazy too!!!!
Rick
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I have a 4" 3Jaw Scroll an 2 4Jaws independent, a 4" and a 6" for my 8"x20"
I am not lay about changing but the 6" is pretty heavy for my taste.
Unless I am sure I can finish a part in one chucking or I am not concerned about concentricity I mount one of the 4 jaws.
To change from 4 to 3 I must predict a number of chucking and re-chucking sufficient to offset the labor of changing out and the slight penalty of centering.
In other words, a couple of low grade operation do not warrant changing to a 3 jaws.
To use a 4 jaws effectively, it is important to develop a technique for fast, non iterative, centering. A second, stubby key is indispensable.
I am not lay about changing but the 6" is pretty heavy for my taste.
Unless I am sure I can finish a part in one chucking or I am not concerned about concentricity I mount one of the 4 jaws.
To change from 4 to 3 I must predict a number of chucking and re-chucking sufficient to offset the labor of changing out and the slight penalty of centering.
In other words, a couple of low grade operation do not warrant changing to a 3 jaws.
To use a 4 jaws effectively, it is important to develop a technique for fast, non iterative, centering. A second, stubby key is indispensable.
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I may use the 3-jaw slightly more than the 4-jaw, but if I only had to have one chuck it would be the 4-jaw. I have one "normal" size for my lathe and a larger 4-jaw for larger work (cautions and caveats apply here, but sometimes it helps me expand the capability of my small lathe.)
"To use a 4 jaws effectively, it is important to develop a technique for fast, non iterative, centering. A second, stubby key is indispensable." Absolutely, I agree and there's a learning curve. Unfortunately, the 4-jaw that I ordered at the same time as my lathe had very bad worms and very rough teeth on the backs of the jaws and it took me longer than it should have to get the adjustment process right. I bought a new chuck and nailed the procedure in about an hour.
--ShopShoe
"To use a 4 jaws effectively, it is important to develop a technique for fast, non iterative, centering. A second, stubby key is indispensable." Absolutely, I agree and there's a learning curve. Unfortunately, the 4-jaw that I ordered at the same time as my lathe had very bad worms and very rough teeth on the backs of the jaws and it took me longer than it should have to get the adjustment process right. I bought a new chuck and nailed the procedure in about an hour.
--ShopShoe
jj-smith
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