# Collet chucks and lathe dogs



## tjb (Jan 29, 2020)

All of my experience on lathes has been with 3-jaw chucks.  I have a 4-jaw and know how to set it up but have never had an occasion to do so.

I am aware that there are such things as 5C collet chucks, but I've never used one and have never seen one in use.  What are their advantages and disadvantages?  Same issue with lathe dogs.  Any other preferred work holders for lathes?

Any observations from our resident experts would be much appreciated.

Regards,
Terry


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## projectnut (Jan 29, 2020)

Not necessarily a resident expert, but I will offer an opinion.  First off most collets will only accept small diameter work.  The collets fit into a chuck that is in some manner attached to the lathe spindle.  For anything over a few inches long the spindle bore is the limiting factor as to the diameter of the part that can be machined.

5C collets for instance have a generally accepted working diameter of 1 1/16".  Some manufacturers make specials up to 1 1/8", but they have limited holding power due to the small amount of material left in the collet that is able to hold the work piece.  There are also expanding internal and external collets that fit 5C chucks.  I have a number of them able to hold work up to about 3" in diameter.  These collets again can only hold short length work pieces unless the opposite end is supported by a center in the tailstock.

The runout on most high end collets is within a couple tenths of an inch (.0002") as opposed to a 3 jaw chuck which can be as much as .002" to .003".  A four jaw chuck can in most cases be dialed in to a similar runout as a collet.  The big difference is in the amount of time it takes to do it.  

As with any tool you get what you pay for.  The most accurate 5C collets (in my opinion) are made by Hardinge.  They are hardened and ground to within .0002" TIR. These collets generally sell for around $70.00 per copy.  Less expensive import collets generally have a bit more runout as in .0004" to .0006".  However they generally sell for less than $10.00 per copy.

As for "hobby grade" machinery I doubt that most would have a spindle run out in the .0002" range, so using a high performance collet wouldn't necessarily achieve the minimal run out that could be achieved in a professional grade machine.

I have mostly 5C Hardinge 5C collets in 1/64" increments to 1 1/16".  Over the years some were worn out, lost or damaged.  since they are no longer used in a commercial situation where parts need to be inspected and certified I replaced them with imports from Shars.  Their high precision" line has a run out of .0005" as opposed to their "standard" versions which have a run out of .0006".  There's only about a $2.00 difference between the price of the standard and high precision models.


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## ttabbal (Jan 29, 2020)

Collet chucks, there are a number of types, are great when you need to remove the part but maintain concentricity. They can also grip finished parts without damaging them. They also don't have jaws protruding from the face, so you can work closer to the chuck safely. The last is the only thing that you can't do with a 4 jaw and something to put around the part though. Honestly, they are really nice for production shops, but less so for hobby users. I got an ER40 chuck mostly for working in close and with gravers, which I have yet to use. It's handy and I'm glad to have it. I'm not sure I'd recommend anyone purchase unless you plan to use it frequently though. 

Dogs are for turning between centers. You put a dead center in the spindle and tailstock and use a drive dog to turn the part. You can get longer parts in the lathe this way, and you can remove the part and place it back without losing concentricity. Usually you would mount the face plate to the spindle to drive the dog. I've only done this a couple of times. 

The face plate can be used like a mill table for clamping parts to. I've only ever seen it on YouTube, never tried it myself.


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## talvare (Jan 29, 2020)

A few other advantages to using the collets is speed of changing parts (especially with lever actuated collet chucks), they are very good for holding thin wall parts without causing distortion, there is a lot less stick out from the lathe spindle vs a typical 3, 4 or 6 jaw chuck. There are step collets available for holding a part both internally or externally and these can be machined to hold a part of the exact dimensions desired. These can be very useful for machining thin rings or discs.

Ted


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## benmychree (Jan 29, 2020)

ttabbal said:


> Collet chucks, there are a number of types, are great when you need to remove the part but maintain concentricity. They can also grip finished parts without damaging them. They also don't have jaws protruding from the face, so you can work closer to the chuck safely. The last is the only thing that you can't do with a 4 jaw and something to put around the part though. Honestly, they are really nice for production shops, but less so for hobby users. I got an ER40 chuck mostly for working in close and with gravers, which I have yet to use. It's handy and I'm glad to have it. I'm not sure I'd recommend anyone purchase unless you plan to use it frequently though.
> 
> Dogs are for turning between centers. You put a dead center in the spindle and tailstock and use a drive dog to turn the part. You can get longer parts in the lathe this way, and you can remove the part and place it back without losing concentricity. Usually you would mount the face plate to the spindle to drive the dog. I've only done this a couple of times.
> 
> The face plate can be used like a mill table for clamping parts to. I've only ever seen it on YouTube, never tried it myself.


A face plate is not much good for driving lathe dogs, the proper accessory is the driving plate, made for driving lathe dogs, it has one large slot that goes from close to the spindle, outwards to the periphery of the plate, that is, an open slot, and the plate usually has several other (closed) slots, and driving plates are generally about half the diameter of the faceplate.


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## middle.road (Jan 29, 2020)

I've been kicking around an er32 or er40 setup for my 1440.
Did you get a faceplate with your 1440?

One chuck is the MT5 style but limits sliding stock through the spindle. And you need to make up a drawbar.
They won't be as accurate as a high-end 5C setup, just depends on the budget.


The other idea I'm kicking around is to take one of these and mount it to my faceplate _if_ I can get it dialed in.


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## DavidR8 (Jan 29, 2020)

I'm with @middle.road on this too. I'd like to have collet capability so that I can use an end mill with my milling attachment.


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## tjb (Jan 29, 2020)

middle.road said:


> I've been kicking around an er32 or er40 setup for my 1440.
> Did you get a faceplate with your 1440?
> 
> One chuck is the MT5 style but limits sliding stock through the spindle. And you need to make up a drawbar.
> ...


Yes, I got a faceplate, but it's a monster.  Haven't measured it, but it's at least a 10".  It sounds like collets are a little more specialized than anything currently on my radar screen.  As expected, all the answers here are quite helpful - something I'll need to study to see if it makes sense to purchase.

Keep the info coming, guys.

Regards,
Terry


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## Tozguy (Jan 29, 2020)

For general use I like the ER collets because of the range of size a single collet will hold. I also a have accumulated a few MT3 collets and R8 collets in sizes that I bought for specific jobs that required more precision than ER collets can provide. 
For end mills in the lathe spindle I use MT3 Weldon holders which are reasonably priced and more convenient than using a collet. 
Using an ER collet block held a four jaw chuck gives you the possibility of holding long work.


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## Tozguy (Jan 29, 2020)

For dogs I have found that a bent tail dog will often catch well in the jaws of a chuck. No need for a driving plate. However there are many ways to improvise a dog and it may even be that store bought dogs won't work in all scenarios. Unless you have a specific job ahead of you I would start by having a look at some of the ideas people come up with (can you say hose collars and angle brackets) for driving between centres.


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## BGHansen (Jan 29, 2020)

I have two lathes, a Grizzly G0709 14" x 40" and a Clausing 5418 (12" x 24").  I leave a set-tru 3-jaw on the Grizzly and a 5-C collet chuck on the Clausing.  The Clausing is my go-to for collet work even though I have a full set of 5-C collets and a lever-style closer for the Grizzly.  Frankly, it's just easier for me to leave the Clausing set up with the 5-C collet chuck.

My chuck is from CDCOtool.com.  The even 1/32" collets are from CDCO also, added the 64's ones from CME tools out of the Detroit area.  My chuck took a little finessing to get dialed in, but was at about 0.0002" run-out at the collet mating face last I checked it.  I've had no issues with the collet chuck or collets.

5-C Collets are great for a very short diameter range, that's why they sell them in 1/64" increments.  They are great for gripping on the perimeter without marring material.  As mentioned above, great for multiple set-up jobs as your concentricity is much closer than most 3-jaws.  I generally throw stock in a collet and when slowly advancing the cutter tool hit the entire diameter at once.

Down side is you have to spin the chuck key around 20 revolutions to change a collet.  I have a 3/8" square drive adapter mounted in a Makita cordless for collet changes.  Probably haven't had a regular chuck on my Clausing in 3 years.  But that's the advantage of 2 lathes.

I used a lathe dog once turning between centers.  Did it just so I could say I have.  I center drilled both ends with a set-tru 3-jaw, so really didn't need the dog.  More experienced guys will have better feedback for you.

Bruce


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## mikey (Jan 29, 2020)

Turning between centers is theoretically the most accurate way to turn something on the lathe. It requires that the 60 degree center holes be accurately made and that the dead center in the spindle be accurate. It is also recommended that you use a hardened and accurate dead center in the tailstock that is properly aligned; however, most of us use a live center for this because it doesn't require lubricating the tip and is less likely to expand and tighten up as the part heats up.

Between centers work requires a drive dog and the type of dog you get depends on what you use to drive it. If you have a drive plate (like benmychree pointed to) then the dogleg one with a bent tail is better. These will also work to hook one of the jaws of jawed chuck. My spindle has a threaded hole for a post that catches a dog with a straight tail; it is very rigid and I prefer it over a separate plate. So, the dog depends on the driver.

5C is great for production work on nominal diameter stock. If you do a lot of this then 5C is the ticket. 5C collets have a gripping range of only about 0.005" so the stock must be close to the diameter of the collet or it won't grab solidly or accurately. In a hobby shop, we may start with nominal stock but much of the stuff we use is a remnant from another project so a 5C isn't great for that unless you happen to have a collet that is within 0.005" of the remnant's diameter. For this, another kind of work holder is better.

Collets are good for speed, for holding finished/threaded or thin-walled parts. They are more accurate than a 3 jaw, not as potentially accurate as a 4 jaw independent chuck but are convenient. If I had to choose a collet system for a hobby shop that does work on a lot of non-nominal stock, I would pick an ER system. Unless you're using it on precision ground stock, run out on most import chucks and collets will be satisfactory. The ER system was not designed to be a work holding system; it is a tool holding system for the mill and there, good chucks/collets/nuts provide a very accurate set up. On the lathe, this is not nearly as critical.

In my shop, I would guess I use the 3 jaw the vast majority of the time. This may change because I now have a 6 jaw Set-rite PB chuck in my grubby hands. The 4 jaw comes out when I need accuracy. The ER-40 chuck is used for finished turned or threaded stuff or thin-walled stuff so it doesn't get used much; interestingly, that chuck is as accurate as a typical milling set up. Since my spindle has zero run out, the whole affair is pretty good. I almost never turn between centers unless I'm making a test bar so I'm of little use there.

Hope this helps.


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## tjb (Jan 29, 2020)

Tozguy said:


> MT3 Weldon holders


Never heard of that.  Sounds interesting.  Thanks for the tip.

Regards,
Terry


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## darkzero (Jan 29, 2020)

Don't see hobbyist turning between centers much these days. Doesn't even look like they make drive plates anymore so many people will just use a faceplate to drive a dog. Could easily make a drive plate out of a blank chuck backplate though.

I'm just an amateur at best but I was taught to turn between centers at the local college. One great advantage of turning between centers is you can remove the work from the lathe for whatever reason then easily put it back in without having to reindicate.

Like when I was making the spider for my lathe. I had no way of checking thread fit at the back of the spindle. So I made the spider turning between centers. I could simply remove it to check thread fit then continue single pointing till I got where I needed to be.





Also at the local college I loved running the 5C collet closures on the Leblonds. So quick to use & was even taught to remove & replace the work piece without needing to turn off the spindle. Had no idea that could be done. I don't do any production work regularly so wouldn't matter to me to have one at home.

In relation to what Mike said, I don't work with nominal diameters a lot. Well I do but the workpiece will get turn down to a nominal diameter, many of my projects will start with nominal stock then turned down to whatever. I built me a ER-40 collet chuck for the lathe, well cause everyone was doing it haha, thought I would need one. Well the truth is I have used it less than a handful of times. Between my 6-jaw Set-Tru & 4-jaw I don't benefit from a collet chuck, not for an accuracy standpoint, really only to prevent knuckle busting. But that's just me with the stuff I do.


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## tjb (Jan 29, 2020)

darkzero said:


> Don't see hobbyist turning between centers much these days. Doesn't even look like they make drive plates anymore so many people will just use a faceplate to drive a dog. Could easily make a drive plate out of a blank chuck backplate though.
> 
> I'm just an amateur at best but I was taught to turn between centers at the local college. One great advantage of turning between centers is you can remove the work from the lathe for whatever reason then easily put it back in without having to reindicate.
> 
> ...


So is that a 'driving plate' that has been referenced earlier holding the lathe dog?  Making a spider for my current lathe is on my to-do list.  (Could have used it today, actually, if I had one.)  Thanks for the info.

Regards,
Terry


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## darkzero (Jan 29, 2020)

tjb said:


> So is that a 'driving plate' that has been referenced earlier holding the lathe dog?  Making a spider for my current lathe is on my to-do list.  (Could have used it today, actually, if I had one.)  Thanks for the info.
> 
> Regards,
> Terry



Yes, mine is an actual drive plate although I've never seen another one like it. I asked here if anyone could identify it but no responses. I found it on ebay.

Drive plates commonly look like this below. Some may have an additional slot on the opposing side or a pin sticking out to drive a straight dog.


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## DavidR8 (Jan 29, 2020)

Looks like my South Bend plate.
(well yours is cleaner  )


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## darkzero (Jan 29, 2020)

Oh that one is not mine. Mine is the one above it and is a D1-4 mount. Found the pic on the interwebs but yes the name of the file was southbend9-10k.

Edit: Here's mine. It's like 9" dia. Wish I knew where it came from.


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## pontiac428 (Jan 29, 2020)

Turning between centers is ideal for minimizing deflection, especially on long or thin parts.  It is my rule (maybe I picked it up from reading all those antique machining books, I dunno) to always attempt to work between centers on anything long enough to be supported and still have room to work.  This setup is very steady and secure, while being easy to use and fast to mount.  I frequently use dead centers in both ends (which is technically called a live center on the drive side, and a dead center on the tailstock side) unless I'm working on something that I can't sacrifice the center drilled ends on.  Then I go live center.  Dogs  can work on very small diameters, or shaped profile stock.  I like working this way, so I do it a lot.


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## darkzero (Jan 29, 2020)

pontiac428 said:


> I frequently use dead centers in both ends (which is technically called a live center on the drive side, and a dead center on the tailstock side)



That's how my instructor taught me. "Solid" center in the spindle is a Live Center & a solid center in the tail stock is a Dead Center. There were no ball bearing centers in his day.

So this is what I used to say on another forum (not machining related but there was a machining section). People would say I was wrong & rather than having to keep explaining myself I just stated calling ball bearing centers Live Centers like everyone commonly does now. Keeping up with the times I guess which is my time anyway. I always do use a live (BB) center though in the TS. Plenty accurate enough for me.


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## francist (Jan 29, 2020)

Ahh, someone else who maintains the proper nomenclature...


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## middle.road (Jan 29, 2020)

DavidR8 said:


> Looks like my South Bend plate.
> (well yours is cleaner  )


Grab ya some emery cloth, steel wool, vinegar and get to cleaning dem pieces up! Hut-Hut...   
Especially those jaws. -hehe
***edit***
Oh yeah, I forgot - wire brushes also.


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## projectnut (Jan 29, 2020)

pontiac428 said:


> Turning between centers is ideal for minimizing deflection, especially on long or thin parts.  It is my rule (maybe I picked it up from reading all those antique machining books, I dunno) to always attempt to work between centers on anything long enough to be supported and still have room to work.  This setup is very steady and secure, while being easy to use and fast to mount.  I frequently use dead centers in both ends (which is technically called a live center on the drive side, and a dead center on the tailstock side) unless I'm working on something that I can't sacrifice the center drilled ends on.  Then I go live center.  Dogs  can work on very small diameters, or shaped profile stock.  I like working this way, so I do it a lot.



The old school rule of thumb ( I hope it still applies) is that a workpiece can extend beyond the collet (or chuck) 5 times it's diameter before  needing the support of a center in the tailstock.  As far as I know this "rule of thumb" was meant to apply to any common metals.  I doubt it would apply to most plastics.


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## MrWhoopee (Jan 29, 2020)

francist said:


> Ahh, someone else who maintains the proper nomenclature...



Ah, someone else who knows the meaning of nomenclature and isn't afraid to use it in a sentence...

The machinists I've worked with rarely used a center inserted in the spindle. When turning between centers, they would chuck a soft center (or make one if they couldn't find the old one), true it up by re-cutting the point and drive the dog with a chuck jaw. Way easier than removing a 12-16 in. chuck.


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## Alcap (Jan 30, 2020)

I'm a beginner   but  thought  I would say something about ER32 collets , I bought a cheap set along with a hex collet block . I used them last night when I wanted to take some 1/4"-28 allen cap screws that needed to be faced off about .060" . By putting the hex collect block into the 3 jaw chuck completely I was able to do those bolt very easily . With the collet block I could also feed stock though the spindle though  like all those small machines that's limited


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## middle.road (Jan 30, 2020)

Alcap said:


> I'm a beginner   but  thought  I would say something about ER32 collets , I bought a cheap set along with a hex collet block . I used them last night when I wanted to take some 1/4"-28 allen cap screws that needed to be faced off about .060" . By putting the hex collect block into the 3 jaw chuck completely I was able to do those bolt very easily . With the collet block I could also feed stock though the spindle though  like all those small machines that's limited


Good option, plus you can use it on the mill also.


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