Small chuck for small parts

[GregLaROCHE]

I have a mini lathe that has really come in handy. However, I find myself making a lot of small parts like screws etc. The jaws are often too big, so I end up having to use a larger diameter piece of stock and cutting it down.

I was thinking of getting a small drill chuck with a straight shank and mounting it in the three jaw chuck to hold smaller diameter stock. Is this a good idea, or would I be adding problems with concentricity. Maybe trying to find a smaller chuck would be the best way to go. What do others think?
Thanks

[Ed K]

Collets are great for smaller work in a standard lathe. I don't know what is available for your mini lathe

[15meter]

Do a search for ER-32 chucks and collets, you'll probably find some thing you can use. I have an old South Bend 9x24 that has both a 3 and a 4 jaw chuck and 3MT collet holder and set of collets. The collets get 80-90% of the work, the three jaw for almost everything else. Probably should sell the 4 jaw as much as I use it.

[KCSO]

I made a collet adapter for my Mini and just use the left over collets from my MT3 milling machine. They cover most screw sizes. In addition I took and old drill chuck and went in and bored a recess in the jaws so I can hold a screw head and leave a section of shank hang out for shortening screws. I used a dermal cutter in a holder on the table and cut the recess just like you true a 3 jaw.

[skeettx]

Something like this??

https://www.dremel.com/en_US/products/-/show-product/accessories/4486-dremel-chuck

[RED BEAR]

I would have to go with a collet set up it has been my experience that these small chucks ether don't run true enough or have the holding strengths for machine work. Maybe ok for light machining but never as good as a collet.

[6bg6ga]

Uni mat lathe

[Jeff Michel]

NO eBay Links

You'll have to make or buy a suitable back plate. These work pretty good, I have one for my Myford Super 7 and one mounted on a dividing head.
Evidently, I can't place an ebay link. Did as past practice, unaware it is forbidden.

I would suggest a ER 32 collet chuck, they are pretty inexpensive and really common on various auction sights on the web.

[GregLaROCHE]

The collets seem like a good idea. Do they go down to really small sizes?

[deltaenterprizes]

Check out Micro Mark, they have plenty of tools for small parts!

[JimB..]

Yeah, collets. They go down as small as you need.

I used to have some that fit in the MT3 of my SB9, you can also get a chuck for each of the various types of collets. You can even get collets for bar stock, square or hex, that are sometimes very useful.

If you want to dive deep, practical machinist forum, if you want to start shopping littlemachineshop is a good place to start.

[15meter]

ER32 series collets have a capacity of .02-.787 inches. Each ER32 collet has a range of .039 inches(1mm). ER32 Collets .094 and smaller have a range of only .015 inches. The size indicated on the collet is the largest size it can hold and can be collapsed smaller within its collapse range mentioned above. For example, ER32-1/4 can grab a round shank from .250 diameter to .211 diameter.

Ah, the ease of cut and paste......

[country gent]

There are collet chuck sets with a straight spindle that can be held in the chuck. Another route is to by a 1/4" or 3/8" drill chuck with threaded mount. Turn up a 1/2" or 3/4 shank with the thread and a shoulder. leave the shank large when starting .050 is plenty. Install tight in chuck with Loctite. while Loctite is curing set up and turn a mandrel in the lathe to just under chucks largest dia. Do not remove but chuck on this to hold as its running dead true. now lightly turn the shank true and to size. This can be used got small parts and when worn a mandrel can be turned and the shank dressed down back to true. My mini lathes chuck goes down to under 1/8" even after being ground in to true.

[Jedman]

Are you sure your lathe spindle is not already bored for a MT1 or other tapered shank ?
There are many types of mounts for drill chucks, maybe there is something already made to use a drill Chuck in the spindle.

Jedman

[Drm50]

I bought a machinist box full of good stuff. One of the neatest things was a 3/16" Jacobs Chuck that is mounted on a 1/2 " shank that has been turned to fit. It's handy for turning firing pins and such that don't require .001" tolerances. I think it was some old machinists ace in the hole.

[country gent]

I have Jacobs chucks on 1/4" 3/8" 1/2" and 3/4" shanks not so much for use in the lathe but on Bridgeport's with manual r collets its easier to loosen spindle tap and change cutter to drill chuck than to completely unscrew and use a r series mounted chuck. The last is a 0-1/2" Jacobs on a square shank for use in the mill vise. Makes cutting simple squares and flats quick and easy. But I have used the 3/4 in lathes occasionally.

[GregLaROCHE]

Are you sure your lathe spindle is not already bored for a MT1 or other tapered shank ?
There are many types of mounts for drill chucks, maybe there is something already made to use a drill Chuck in the spindle.
Jedman

I believe the spindle is a MT3. Putting a small drill chuck on with one, is one of the things I was thinking about. Collets seem a good way to go, but start to get pricey.

[EDG]

The standard collet format for tool room lathes is the 5C. You can find the 5C collets and collet chucks on ebay for photos. So far as I know the 5C is too large for your mini lathe. You need to find a similar but smaller collet set for your lathe. Those collets will look a lot like RCBS bullet puller collets.
You will not like the price because you have to buy a number of individual collets to get a wide variety of sizes. The advantage is the little collets will hold tiny work pieces that nothing else can hold. The collets also run very near true which is not the case with many other chuck types. No drill chuck is designed to take side loads. The jaws of a 3 jaw will damage threads on screw shanks if you chuck on the threads to turn the screw head. You have to drill and tap a slug in your lathe and thread the screw into the slug in order to turn the head. A collet can chuck on the threads without damaging a screw.



I have a mini lathe that has really come in handy. However, I find myself making a lot of small parts like screws etc. The jaws are often too big, so I end up having to use a larger diameter piece of stock and cutting it down.

I was thinking of getting a small drill chuck with a straight shank and mounting it in the three jaw chuck to hold smaller diameter stock. Is this a good idea, or would I be adding problems with concentricity. Maybe trying to find a smaller chuck would be the best way to go. What do others think?
Thanks

[indian joe]

The collets seem like a good idea. Do they go down to really small sizes?

Greg
I bought a straight shank ER-32 collet chuck and a set of collets 13mm down to 1 mm for less than fifty bucks off Ebay. My 3 jaw chuck is really good and those collets are amazing what you can do with them - and it is such an easy setup ......now here come the experts to tell us ya cant get a good enough setup by throwing that straight shank holder in a 3 jaw chuck ....well it works just great at my place !!! I also bought a morse taper collet chuck for my mill for the same set of collets.

You do not need to spend a mint on fancy brand machinist quality stuff ! Get the chinese "junk" it will be the best fifty bucks you ever spent ----need to check that your mini lathe chuck will take the shank first. My collet set will take anything from 1mm up to 13 mm including firmly hold bullet shells like 22/250 - 303 brit etc - I think the collet set was somewhere mid thirty bucks landed in my mailbox.

[kenton]

One thing to be aware of with ER series collets (ER32, ER16, ER25...) is that they close from the front and back. So if you have short piece that only engages the front of the collet you can end up with a collet bore that is tapered. This can be worked around by putting a piece of stock the same size in the back of the collet and for non critical parts with light cuts it may not matter at all.

[BigEyeBob]

Check out Bangood.com they have er32 collet chucks that mount on mini lathes with a back plate,either 90mm or 100mm IIRC .Chinese but good quality for the money .They have the collets as well .

[indian joe]

I told you fellers a fib ---I bought ER20 stuff instead of ER32
smaller - cheaper - works good

[Jedman]

Greg , For what it sounds like you are doing with a mini lathe, a drill Chuck is all you need to make screws, short firing pins, ect. You can get a Chinese made chuck with a MT 3 shank for under $20 that will do anything your light duty mini lathe is designed for.
ER series collets are OK but from each size to the next they wount hold every diameter in between, they are pretty specific to what size they will hold. A drill chuck will do more, cost less, and be faster.

Jedman

[jmorris]

I was thinking of getting a small drill chuck with a straight shank and mounting it in the three jaw chuck to hold smaller diameter stock.

I have done this a number of times. Lots of 1/4” & 3/8” drill chucks out there that have 3/8-24 threads. You can cut the head off a long fine thread bolt and clam that in your 3 jaw or machine your own arbor.

I also have a couple I threaded the bolt into a file handle. Allows me to hold small parts by hand. Like sharpening a small tungsten for TIG welding.

[kenton]

Greg , For what it sounds like you are doing with a mini lathe, a drill Chuck is all you need to make screws, short firing pins, ect. You can get a Chinese made chuck with a MT 3 shank for under $20 that will do anything your light duty mini lathe is designed for.
ER series collets are OK but from each size to the next they wount hold every diameter in between, they are pretty specific to what size they will hold. A drill chuck will do more, cost less, and be faster.

Jedman

ER collet have a large grip range, usually 1/32 or 1mm (.0394"). They grip best at their nominal size but will grip through their entire travel.

[Jedman]

ER collet have a large grip range, usually 1/32 or 1mm (.0394"). They grip best at their nominal size but will grip through their entire travel.

I have a set of ER 25 collets that range from 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 5/8"
there are a lot of sizes they wount hold. I know you can get a 15 pic. set that are 1/16 apart but by time you buy that set and the tool holder, and draw bar you have half the price of the lathe.
On a mini lathe he probably wouldn't use anything larger than 3/8" and maybe as small as .062.
Making screws , pins , ect you don't take more than a .003 cut , we're talking very light duty.

Jedman

[indian joe]

I have a set of ER 25 collets that range from 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 5/8"
there are a lot of sizes they wount hold. I know you can get a 15 pic. set that are 1/16 apart but by time you buy that set and the tool holder, and draw bar you have half the price of the lathe.
On a mini lathe he probably wouldn't use anything larger than 3/8" and maybe as small as .062.
Making screws , pins , ect you don't take more than a .003 cut , we're talking very light duty.

Jedman

Jedman
That must be a heckuva cheap lathe you got:-D

on ebay right now
set of ER20 collets 1mm to 12mm = $21.15
ER20 x MT3 collet holder(chuck) = $15.99
both free shipping total = $37.14 US
hardly gonna break the bank -- make the drawbar its only a long bolt and a couple washers
If the mini lathe would take it I would go for a 5/8th inch parallel shank chuck instead of (or as well as) the MT3 - but the spindle bore might not take that 5/8th shank??

[kywoodwrkr]

Jedman
That must be a heckuva cheap lathe you got:-D

on ebay right now
set of ER20 collets 1mm to 12mm = $21.15
ER20 x MT3 collet holder(chuck) = $15.99
both free shipping total = $37.14 US
hardly gonna break the bank -- make the drawbar its only a long bolt and a couple washers
If the mini lathe would take it I would go for a 5/8th inch parallel shank chuck instead of (or as well as) the MT3 - but the spindle bore might not take that 5/8th shank??

Second this approach.
Bought the ER32 holder and ER16 straight shank holders - both. The first ER16 holder was a screwup and bought MT3(Morse Taper 3) not useful for my task at hand.
C20 ER16A 100L Collet Chuck Holder CNC Milling Extension Rod Straight Shank $9.95 delivered.(in a month!)
Useful in mill as well a lathe.
YMMV

[targetfreak]

"Little Machine Shop". Google the web address. (just to keep from being blocked on this forum)
They make THE BEST small machine tool accessories, for reasonable prices. Been using them for years.
A three-jaw chuck does not run true, unless one is very lucky to get an oddball.
ER collets are expensive and require adapters, and don't work on all machines.
3C and 5C collets, and Morse Taper (MT) collets might just mount directly into your headstock.
Can't recommend LMS enough! They are superb people.

[uscra112]

Agree about Little Machine Shop. I've been using one of their quickchange toolposts on my benchtop for well over ten years now. Bought another for my South Bend 10" Heavy toolroom lathe when I finally installed it in 2013, and it's also been flawless.

[targetfreak]

Agree about Little Machine Shop. I've been using one of their quickchange toolposts on my benchtop for well over ten years now. Bought another for my South Bend 10" Heavy toolroom lathe when I finally installed it in 2013, and it's also been flawless.
I just bought from them a boring head for milling (with the R8 collet fitment). Very well made, and it works. Previously I got MT and 3C collets, and the same QC toolpost.