# Need Advice About Lathe Collets



## divb (Jun 19, 2017)

I am new to the hobby and I recently purchased a Little Machine Shop HiTorque 8.5" x  20" Bench Lathe.  It is their version of the Sieg SC4 lathe.  I really like it and just purchased a set of 3MT Collets from them.  These are great for working on shorter pieces of rod but they are not through hole and will only take work that is a couple of inches long.
I would like a set of through hole collets that would work with this lathe but I have no idea what to buy.  Would someone be able to recommend or point me to a collet set that is through hole?


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## Tozguy (Jun 19, 2017)

ER collets. What size is your spindle bore?
This is one of my homemade ones for a D1-4 spindle nose.
Brino has a different spindle and set up so lets hope that he will be along shortly.
Some here too 
http://www.bealltool.com/products/turning/colletchuck.php


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## divb (Jun 19, 2017)

The spindle bore is 20mm.  I looked at the bealtool link - Thanks.  I'm somewhat confused about how a through hole collet is held.  Mine use a draw bar but the problem is they are not through hole.  How would a through hole collet be held.  Do they use a tube to hold them in?  Yours looks very nice and looks like it mounts to the face plate.  This would be good but then I don't understand how it aligns to the spindle center line.  I'm sure it is obvious to someone more experienced but I am rather new to this.


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## Tozguy (Jun 19, 2017)

The Beall ER chuck screws on to the spindle nose so it is aligned with the spindle and does not need a drawbar. It is hollow so that anything that fits in the collet will will fit through the chuck. (ER32 maximum size is 20mm).
A D1-4 ER chuck like mine will attach to the spindle like any other chuck and not need a drawbar.
What kind of spindle nose do you have?
There are some pics in this thread:
http://www.hobby-machinist.com/threads/is-there-a-definitive-article-on-collets.36227/


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## mikey (Jun 20, 2017)

Just looked at LMS's site and they offer two bolt on ER-40 chucks that fit a 4" spindle mount with three bolts. It looks like they might bolt right onto the spindle - might call and check if one will fit. The spindle bore is only 0.80" ID so even an ER-32 chuck would work, although the ER-40 has a 1/4" more capacity.


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## higgite (Jun 20, 2017)

Hi divb,

I have an LMS 8.5x20 and an ER-32 chuck that looks just like the one that LMS sells.

To answer your question, ER collets fit into a collet nut that screws on to the nose of the ER chuck. The collet is hollow, tapered and split so that as the nut is tightened it forces the the collet back into the tapered nose of the chuck and compresses the collet down onto the work piece. Since it is hollow, you can mount work pieces that extend back into the spindle as long as the work piece has a smaller diameter than the spindle ID.

That said, I occasionally wish that I had bought an ER-40 chuck and collet set so I could at least turn short pieces up to 1” in diameter without changing chucks. Hope this helps.

Tom


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## brino (Jun 20, 2017)

Hi @divb,

It looks like you have some great guidance above.

I just stopped by to say Welcome to the Hobby-Machinist!

-brino


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## divb (Jun 20, 2017)

Thanks very much for the information.  The LMS ER-40 4 inch diameter chuck will fit my lathe and is exactly what I was looking for.  As Tom mentioned I would not be able to use the largest size collets as through hole but could hold shorter pieces of stock with them.
Thanks Brino for the welcome to Hobby-Machinist.  The help and information has been exactly what I was looking for.
With my admittedly limited knowledge collets seem like a much more accurate way to hold round bar stock than a 3 jaw chuck and almost as easy to use (requiring at most a quick collet change).  However on almost all of the youtube videos and blogs that I have seen 3 jaw chucks are used all the time and collets are very rarely if ever used.  Am I missing something obvious?


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## wrmiller (Jun 20, 2017)

The only 'obvious' thing is that collets have a very small workholding range outside of their intended clamping range (hope I said that right...) Collets are great for doing repetitive work on bar stock, whereas I am constantly needing to grab things of varying sizes one right after another. Which is why I use a high quality set-tru 3 jaw chuck which has very little TIR.

Different strokes, different folks. Same result. Oh, and welcome to the forums!


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## brino (Jun 20, 2017)

divb said:


> However on almost all of the youtube videos and blogs that I have seen 3 jaw chucks are used all the time and collets are very rarely if ever used. Am I missing something obvious?



In some limited situations, you just don't care about how concentric the turned end of the bar is to the piece that's in the chuck. Let me explain.......

Mostly that's when you are going to cut all new features on a part. You stick a blank rod in your 3-jaw chuck (that might have say 3 thou. run-out) then if you turn the entire outer surface of the part (even at different diameters) they will all be concentric with each other. After you part it off your work piece is round and all the new features you cut are concentric to each-other and your chuck runout has not mattered! The fact that you reshaped the entire outside of the part means the part has been re-centered about a new axis. That new axis may be 3 thou. away from the axis of the bar still left in the
chuck, but it doesn't matter.

You can even drill holes in the part using a drill bit in the tail-stock and those drilled holes will be concentric to the freshly turned circumference. That's because the the work piece (and chuck) are turning about the lathe spindle axis.

Note:
-in this case you may notice that your first cut is "interrupted" that you just skim one side of the work and the other side is uncut. At this point your work piece will not be round.
-your raw stock needs to start out bigger than the final part diameter plus the offset of the new axis.

However, if you need to re-mount something in your chuck for another operation, or need to create a new feature that has to be concentric with an existing one, then you need to centre that feature that was previously turned. You might not be able to do that to the accuracy required simply due to the chuck runout.

For re-chucking a workpiece you can try to minimize that affect by putting a mark on your work piece (a punch mark, or a sharpie line) inline with jaw #1 and put the work back in the chuck in the same position.

Of course, the ideal is to have a chuck with known low runout, so you don't have to worry about re-chucking a workpiece.

Another factor is cost.....a cheap 3-jaw chuck costs less than the collet adapter and all the collets you'd need to span a much smaller range.

-brino


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## mikey (Jun 20, 2017)

I'd like to add onto the already excellent comments from @wrmiller , @brino  and @higgite.

An ER chuck is useful when turning stuff that is of a common size (like 3/4" OD round rod, etc). If you have more than a few to turn then a collet will hold the pieces accurately and allow you to switch to a new piece quickly. Nominal stock can vary in size but is usually slightly smaller than the stated size; an ER chuck can compress about 0.039" and still hold the work so they're useful. Note that for an initial turning, the work will not be any more accurate than if you held it in a 3 jaw chuck.

An ER chuck really becomes useful when you have already turned a work piece and need to remount it for further work. If you re-mount the work in a 3 jaw chuck, it will have significant run out unless you have an Adjust-tru type chuck like Bill mentioned. An Adjust-Tru chuck allows you to get the work piece concentric with the spindle by adjusting the chuck mount itself, which is really, really nice to have. With enough patience, an Adjust-tru chuck can be made to run with almost zero run out. Lacking one of these chucks, an ER collet chuck will allow an already turned piece to run with minimal run out. The amount of run out will depend on the run out of your chuck/collet/nut system. My ER chuck will mount a piece with 0.0001" actual run out so its pretty accurate. Not all chucks will do this but most will be close enough for most purposes.

ER chucks are also able to grab a threaded work piece without doing much, if any, damage to the threads. Don't underestimate the value of this. They also grab without damaging the surface being held like a jawed chuck can and this is especially valuable when the part being grabbed is a bearing surface or if the material is soft.

ER chucks also have no jaws that can take meat off of your hand. I use gravers and files up close to the chuck at times and a rotating jaw can easily rip off a knuckle if I lose my concentration. In these cases, I use an ER chuck for safety more than anything else.

ER chucks allow you to hold short parts of at least 3/4" length. If the work is shorter than that, the collet may not close down accurately and that can affect your concentricity. As Tom said, you can also hold pieces that are larger than your spindle bore and bury it as far as the chuck body allows. This is handy at times.

The bottom line is that an ER chuck is useful and desirable. It is NOT necessary on the lathe; you can easily get along with a good 3 jaw and 4 jaw independent chuck. Over time, you will find that your 3 jaw chuck is the most often used chuck but when you need to quickly chuck a piece with a fair amount of accuracy and don't wish to fuss with indicating it in with your 4 jaw, the ER is a good option.

I should also mention here that accuracy with any ER chuck is very much dependent on good collets and a good ER nut. Do not expect to have optimal performance if you use cheap Chinese collets and nut. Buy good collets and a good nut, then torque the nut to specs (about 130 lb/ft).


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## wrmiller (Jun 20, 2017)

I have to chuck up things that are already turned, like pistol barrels, and I need the best accuracy I can get, which is why I have a set-tru chuck. I've gotten pretty good with it and can set it up to under a half-thou in a few minutes. Most of the time spent is settup for measuring.

But Mike does bring up a good point about chucks and chuck jaws: I can and have worked very close to my 8" chuck while it is spinning at 1200 rpm plus. Concentration is paramount, or I'll be bleeding all over my nice lathe. So...I compromised. I bought a ER32 chuck that has a 1" diameter spud (for lack of a better term) sticking out the back that I can grab with my 3 jaw chuck.

When working on small stuff like firing pins and such I use the ER32 chuck, held in my 8" 3-jaw. I indicate the ER32 and adjust the set-tru to reduce the TIR to whatever level needed and then chuck the piece to be turned/filed/polished in the collet chuck. Much friendlier environment for my knuckles...  

No thru-hole in the ER32 chuck though, but I don't require that when working on really small stuff.


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## mikey (Jun 20, 2017)

On the other hand, nothing increases sphincter tone like working up close to a spinning chuck running at high speed. Good way to remedy or prevent fecal incontinence!


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## wrmiller (Jun 20, 2017)

The first time I spun up this 8" PBA to over 2k rpm I was only slightly amazed to find myself backing up slightly as it spun up to full speed. I am used to it now, but it was an impressive sight the first couple of times.


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## ddickey (Jun 20, 2017)

You might want to check here.
http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks/ER40-Lathe-Collet-Chucks
About $45 cheaper. Not sure about shipping though.


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## higgite (Jun 20, 2017)

mikey said:


> On the other hand, nothing increases sphincter tone like working up close to a spinning chuck running at high speed. Good way to remedy or prevent fecal incontinence!


A proctologist friend of mine told me that's exactly what he prescribes for his elderly (ahem) more mature patients. Small world.


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## ddickey (Jun 20, 2017)

Kegel?


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## mikey (Jun 20, 2017)

ddickey said:


> Kegel?



Wrong plumbing but a similar concept!

Only a hobby machinist can figure out how to inject bathroom humor into any subject.


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## ddickey (Jun 20, 2017)

Oh wait, what?


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## ddickey (Jun 20, 2017)

Google time


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## mikey (Jun 20, 2017)

Kegel exercises are intended to strengthen the muscular floor of the perineum through which the female urethra passes. Weakness of the perineal floor is a common cause of female urinary incontinence and Kegel exercises strengthen those muscles, reducing leakage. I suppose if the lathe user is a female then Kegels will automatically be implemented along with anal sphincter contraction so I stand corrected, Duane.


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## higgite (Jun 20, 2017)

mikey said:


> Kegel exercises are intended to strengthen the muscular floor of the perineum through which the female urethra passes. Weakness of the perineal floor is a common cause of female urinary incontinence and Kegel exercises strengthen those muscles, reducing leakage. I suppose if the lathe user is a female then Kegels will automatically be implemented along with anal sphincter contraction so I stand corrected, Duane.


TMI! TMI! Collets aren't supposed to be this complicated.

Tom


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## mikey (Jun 21, 2017)

ddickey said:


> Oh wait, what?



I was eating dinner when I realized my comment about bathroom humor was misconstrued. I meant that hobby machinists, ESPECIALLY ME, are prone to twist anything into something humorous. My apologies, Duane; it wasn't aimed at you.


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## 4GSR (Jun 21, 2017)

higgite said:


> TMI! TMI! Collets aren't supposed to be this complicated.
> 
> Tom


Went from lathe collets to this?

Too much late night TV.  Oops! Wait a minute, Hawaii is in what time zone?


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## Reeltor (Jun 21, 2017)

since this has turned humorous...Save your money and go old school, turn between centers


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## higgite (Jun 21, 2017)

4gsr said:


> Went from lathe collets to this?
> 
> Too much late night TV.  Oops! Wait a minute, Hawaii is in what time zone?



Twilight. 

Tom


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## mikey (Jun 21, 2017)

NOT!!! It was night time when I responded.


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## divb (Jun 23, 2017)

Thanks for all of the information.  I had no idea that collets covered such a wide variety of things.

I had not been able to find a comprehensive discussion of collets on the internet so this forum was perfect and answered everything that I was looking for.  The ER40 collets and chuck mentioned above are exactly what I was looking for.

However I also realized that a 4 jaw chuck can essentially accomplish the same thing.  I also need to measure the run out on my 3 jaw chuck.

Thanks Again


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## Dave Paine (Jun 23, 2017)

divb said:


> However I also realized that a 4 jaw chuck can essentially accomplish the same thing.  I also need to measure the run out on my 3 jaw chuck.
> Thanks Again



Each tool has its pros and cons.  A 4 jaw independent chuck is very useful.  It can hold better than a 3 jaw and be adjusted to run true.  I would not want to be without one, but I also use collets.

A piece of Mikeys earlier post has a couple of important benefits of ER chucks with relevant ER collets over 3 or 4 jaw chucks.



mikey said:


> ER chucks are also able to grab a threaded work piece without doing much, if any, damage to the threads. Don't underestimate the value of this. They also grab without damaging the surface being held like a jawed chuck can and this is especially valuable when the part being grabbed is a bearing surface or if the material is soft.
> 
> ER chucks also have no jaws that can take meat off of your hand. I use gravers and files up close to the chuck at times and a rotating jaw can easily rip off a knuckle if I lose my concentration. In these cases, I use an ER chuck for safety more than anything else.


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## Reeltor (Jun 23, 2017)

Have you seen a Jacobs Rubberflex Collet Chuck system?  When I need to use a collet on my lathe this is my go to tooling.  They were made with various back-plates to mount to your lathe, but I don't know if they have a size to fit your 8-1/2" machine


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## mikey (Jun 23, 2017)

This is a good place to remind folks, especially those who have never used a collet chuck, that there is nothing magic about a collet chuck. It has the potential to hold a work piece accurately, yes, but the contact surface of any collet is rather small compared to a jawed chuck. The collet will hold the work solidly enough to resist cutting forces up close to the chuck but the farther you are from the chuck, the more the potential for deflection. This is especially true if you are using a carbide tool, which will deflect the work piece all by itself. (EDIT: Not fair; a HSS tool will deflect the work piece, too, but not as much as a carbide insert will.)

It is wise to extend the work piece only as far as you need to, and if that extension is greater than 1-1/2 to 2 times the diameter of the work piece then consider using a live center to support the work. This matters when the work must be held to close tolerances but it is also good workmanship if that is important to you. In fact, this advice also applies to a jawed chuck as well.

Deflection is a real thing and it has several sources, primarily the size and material of the work, cutting tool and the way we support the work piece. By supporting the work piece properly we eliminate one factor and minimize the effect of the other. When accuracy matters and tolerances are tight, do all you can to minimize deflection.


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## Wreck™Wreck (Jun 23, 2017)

mikey said:


> This is a good place to remind folks, especially those who have never used a collet chuck, that there is nothing magic about a collet chuck. It has the potential to hold a work piece accurately, yes, but the contact surface of any collet is rather small compared to a jawed chuck. The collet will hold the work solidly enough to resist cutting forces up close to the chuck but the farther you are from the chuck, the more the potential for deflection. This is especially true if you are using a carbide tool, which will deflect the work piece all by itself. (EDIT: Not fair; a HSS tool will deflect the work piece, too, but not as much as a carbide insert will.)
> 
> It is wise to extend the work piece only as far as you need to, and if that extension is greater than 1-1/2 to 2 times the diameter of the work piece then consider using a live center to support the work. This matters when the work must be held to close tolerances but it is also good workmanship if that is important to you. In fact, this advice also applies to a jawed chuck as well.
> 
> Deflection is a real thing and it has several sources, primarily the size and material of the work, cutting tool and the way we support the work piece. By supporting the work piece properly we eliminate one factor and minimize the effect of the other. When accuracy matters and tolerances are tight, do all you can to minimize deflection.


Many collet  designs will hold the part better then a scroll chuck while not damaging it in the process, I have spun a good deal of drills and taps in turret lathes yet have never spun a part in a 5C collet machine, Warner & Swasey push collets are bullet proof  for the most part.

Also Swiss style lathes do the cutting far from the actual chuck  through a bushing that rotates with the spindle with no clamping force, the bushing must have enough clearance to pass the stock without hanging up, it works. This of course requires round stock  that has already been ground to size. A basic explination of how Swiss lathes differ from conventional machines may be found here.

http://todaysmachiningworld.com/magazine/how-it-works-why-swiss/


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## mikey (Jun 23, 2017)

Okay, for the hobby machinists with Swiss lathes, please ignore my comments.


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## The_Apprentice (Jun 24, 2017)

When I was in my young teens and working in my father's shop, 99% of the time the work was being carried out on collets. I will definitely pick some up in the near future, long before I get a 4-jaw chuck I think.


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## mikey (Jun 24, 2017)

I would get the independent 4 jaw chuck first if I were you. Far more useful and accurate.


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## wrmiller (Jun 24, 2017)

Depends on what you use your lathe for I guess. Can't remember the last time I used a 4-jaw chuck. It's been decades though.

Haven't even bothered to unpack the one I got with the 1340. YMMV...


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## mikey (Jun 24, 2017)

wrmiller said:


> Depends on what you use your lathe for I guess. Can't remember the last time I used a 4-jaw chuck. It's been decades though.
> 
> Haven't even bothered to unpack the one I got with the 1340. YMMV...



Says the guy with an Adjust-tru chuck!


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## wrmiller (Jun 24, 2017)

mikey said:


> Says the guy with an Adjust-tru chuck!



Your right Mike. I do sometimes look at things from my perspective only. 

If I DIDN'T have my PBA I would have to use my 4-jaw for barrel work, and any other operation that requires re-chucking a piece. Which is why I bought the set-tru. Hate using a 4-jaw...


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## mikey (Jun 24, 2017)

wrmiller said:


> Your right Mike. I do sometimes look at things from my perspective only.
> 
> If I DIDN'T have my PBA I would have to use my 4-jaw for barrel work, and any other operation that requires re-chucking a piece. Which is why I bought the set-tru. Hate using a 4-jaw...



I hear you, Bill. I keep saying that my Adjust-tru just happens to have 4 jaws but I'm just kidding myself. One day I will own one, too. I tell you, you and Will (@darkzero) are really bad for my budget!!


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## wrmiller (Jun 24, 2017)

Budget?!? What budget?

The nice folks here on the forums (darkzero being one...) blew my so-called 'budget' into the weeds years ago.  

Truth be told, I'm actually glad they did. Now that the money tree is gone (early 'retirement') I can no longer afford any major purchases. The one machine I didn't get was a small surface grinder. Oh well, such is life.

With any luck, my PM machines will last longer than I.


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## brino (Jun 24, 2017)

Wreck™Wreck said:


> A basic explination of how Swiss lathes differ from conventional machines may be found here.





mikey said:


> Okay, for the hobby machinists with Swiss lathes, please ignore my comments.



From the link provided by @Wreck™Wreck:

Expect to pay around $170,000 for a mid-range 20 mm (about 3/4″) unit.​
<whistle> I'm out! 

But that was a great link Wreck, I never had the difference explained before.
Thanks!

-brino


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## benmychree (Jun 24, 2017)

Reeltor said:


> Have you seen a Jacobs Rubberflex Collet Chuck system?  When I need to use a collet on my lathe this is my go to tooling.  They were made with various back-plates to mount to your lathe, but I don't know if they have a size to fit your 8-1/2" machine


There is a Jacobs collet chuck that is smaller than the one pictured, it is the Model 50, and uses series 500 collets with a max capacity of 1" and an O.D. of about 6" on the handwheel


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## Tozguy (Jun 24, 2017)

Ah geez, now I want a Swiss lathe.


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## brino (Jun 25, 2017)

Tozguy said:


> Ah geez, now I want a Swiss lathe.



Maybe if you just drilled a bunch of random holes thru the lathe you have you could convince yourself that you already have one.

-brino


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## Zathros (Jun 26, 2017)

divb said:


> Thanks very much for the information.  The LMS ER-40 4 inch diameter chuck will fit my lathe and is exactly what I was looking for.  As Tom mentioned I would not be able to use the largest size collets as through hole but could hold shorter pieces of stock with them.
> Thanks Brino for the welcome to Hobby-Machinist.  The help and information has been exactly what I was looking for.
> With my admittedly limited knowledge collets seem like a much more accurate way to hold round bar stock than a 3 jaw chuck and almost as easy to use (requiring at most a quick collet change).  However on almost all of the youtube videos and blogs that I have seen 3 jaw chucks are used all the time and collets are very rarely if ever used.  Am I missing something obvious?



You're welcome, I rather use à collet because it is better centered. Any workpiece round and max size of my lathe collet holder I prefer to use collets instead of the 3 or 4 jaw Chucks.
As one mentioned à good but mostly expensive Chuck Ok but collets are quicker removing worpieces and better centered for lot less money.
Just My 2 ct
Grts
T


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## Zathros (Jun 26, 2017)

Brino even à cheap 3jaw Chuck is more expensive here than à complete er25 collet set with holder. It depends where you buy off course and were you live off course but What is keeping you from searching outside the borders. I bought à few sets of the cheapest er series from 11 up to 35 and they deliver more satisfying results than default chuck from the lathe that cost me the same as the whole collet range I have. I guess Chuck are more expensive here in europe.



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## Zathros (Jun 26, 2017)

mikey said:


> Okay, for the hobby machinists with Swiss lathes, please ignore my comments.



I have à made in swiss lathe milling combi set. And their chucks are not that good as I like them to be. So therefor I use collets where I can. Even so I found out that à lot of their acesories are just imported from Some of the better Chinese factories. Which is cheaper to buy directly from the Oriënt side of this 3rd rock from the sun.



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## mikey (Jun 26, 2017)

Zathros said:


> ...this 3rd rock from the sun.



Have never been to Rotterdam but have seen pictures that some friends took of your beautiful city - it is just stunning, especially at night.


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## Zathros (Jun 26, 2017)

mikey said:


> Have never been to Rotterdam but have seen pictures that some friends took of your beautiful city - it is just stunning, especially at night.



That's why I love to ride My bicycle at night also. And make those parts myself often. And off course in lathe and milling forums. 
For My other hobby astronomy it is less suited by light polution tho.


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## darkzero (Jun 30, 2017)

mikey said:


> Says the guy with an Adjust-tru chuck!



I've got 2 Set-Tru chucks & a cheap chuck that I turned into a Tap-Tru but I still use the 4-jaw indy for times I have to dial something in where my Set-Trus won't work.

That and my 4-jaw is bigger than my Set-Tru chucks so it has a larger capacity & it grips much harder. I like my most used chucks to be one size smaller than my 4 jaw. I don't like cranking down on my scroll chucks hard so when I need to really hold something tight I'm happy to use the 4-jaw, plus it's fun dialing in. 

I adapted a collet chuck to my lathe but honestly I never use it. I only use it when I'm working on really small stuff, 6-jaws hitting my knuckles is not fun, I don't want anymore of that pain. I have an ER chuck & it's slow to use. Maybe if I had a 5C collet closer setup I would use them more but I doubt I will ever go that route.


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## Wreck™Wreck (Jul 1, 2017)

One of the advantages of collets is that they do not vaporize coolant as a jawed chuck will, turn an 8" 3 jaw at 3000 RPM's with flood coolant and it creates a fog that will get everywhere.

Was turning 8-32 threads .225" long to a shoulder today in a 3 jaw, started at 1500 RPM's but the coolant was getting out of hand and backed it down to 1000. With a collet chuck I would have run it at 3000 without issue.
Pesky little buggers to run in a 15 X 40 lathe, only 40 parts however.


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