Are ER 32 collets safe to use on a small milling machine?

Consider whether the big names in tooling would actually offer ER series collet chucks if they were not safe to use. The CNC tooling catalogs are full of them.

Your source is misinformed or ignorant, but willing to share.:-)

Cheers Trevor Jones

Just to add to Trevor's comment, I have used milling cutters ER25 collets in a 2MT collet chuck for many years with no problems, even up to 16mm/5/8" (the largest size you can hold in ER25). Provided you tighten the collet holder adequately, it should not pull out.

It is, of course, absolutely essential with any taper shank holder for milling cutters to use a drawbar.

"Vector forces" is your original contact's (illogical*) way of describing the tendency of any cylindrical object held in a rotating chuck to pull out of it if subjected to sideways forces. A drill chuck is quite inadequate to resist this for any but the lightest of forces; properly designed collet chucks should manage fine. BTW, so do objects held in lathe chucks, otherwise they also would pull out under the same forces (as they will, if supported by a incorrectly centred steady).

*"Illogical" because all forces are vectors, so the phrase is somewhat uninformative.

David

Know any inexpensive sources for MT2 collet chucks? Either ER series, or posilock/Autolock.

Cheers Trevor Jones

Hi Trevor,

Is this what you are looking for?

"ER-25 collet chuck for the micro mill. The shank is 2 Morse Taper to fit the spindles of the micro mill and other machines with a 2 Morse taper spindle..

A spanner wrench is included.

The drawbar thread is 3/8"-16. Part Number: 2230 Weight: 6.00 pounds

Price: $49.95"

From Little Machine Shop. See:

I don't know if it is a good price or not, but comparing some other items LMS carries it should be reasonable.

I'm dope slapping myself for not looking there sometime in my look around. DoH!

Yup! That's pretty much what I'm looking for, and they look as cheap as any I have seen, for ER series.

I wonder if the collets and chuck set go on sale?

Gonna have to keep an eye on them. :-)

Thanks for the pointer Leon.

Cheers Trevor Jones

>

======= also see

strictly for milling you won't need the full set of collets -- only those for the end mills you use. see The ER25 collets seem to be more common than the ER20s

Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.

Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.

>>

I bought the MT2 ER-25 collet set from LittleMachineShop for use on my Atlas 618 lathe. I find it a great product.

One thing to consider if going this route is the clamping range. You can get the collets in inch or metric. The clamping range of the collet is about a mm and the metric set includes a total of 15 collets that cover the entire range. If you go with inches, then there is a lot of overlap and it takes 19 collets to cover the entire range. The information on the website about range for the inch collets was not quite accurate before and I discussed this with LMS. I don't know if it's been corrected yet.

HHIP and LittleMachineShop are the same company. Chris is a very upstanding guy and a pleasure to deal with. I would highly recommend them.

-Bruno

Hi Trevor,

I've been perusing their website and catalog recently looking at things I may want to get. These were still fresh in my mind. I've been eyeing the MT3 collet set (partial set for holding mill bits) that should fit my HF 9x20 lathe among other things...

Bruno's post sounds like he has had good luck in ordering/dealing with them which is nice to know. I haven't ordered from them myself. It only took them ~week to send me a catalog though, a good start.

My lathe isn't up to running just yet so I'm trying to be patient right now and look around more.

I'm glad it helped you out, maybe :)

Many thanks for the advise from all of you, this group is so awesome. Especially the guys that give the answers. I feel better about my ER32 already. LMS are super people, and I dealt with them several times. Always super fast delivery.........Peter

On May 28, 7:04 am, David Littlewood wrote:

"Vector" forces was the term used to describe the forces acting upon the toolholder mounted in the spindle of the mill or lathe. I was not really concerned about the chuck being pulled out of the spindle taper, there's supposed to be a drawbar assembly used with this chuck. The collet chuck in question was 1MT ER25 which is fine in the Sherline lathe or mill provided certain conditions are considered. The shank of the MT1 taper has a max od of under .5". The max. tool shank the collet series can hold is 5/8". The concern when designing this type of tooling is that an inexperienced operator may overload the cutter or cause chip welding which may lead to a failure of the MT1 shank through being bent out of concentricity. Peter's orginal question was if there was a MT1 ER32 series chuck available. Designers must consider that these chucks are going to be used in mills as well as lathes. Lathes are often using tailstocks to help support the cross slide's perpendicular pressure exerted on the workpiece being held in the collet, so small shank size like 1MT is not really a problem, but designing a 1MT ER32 that is holding a 3/4" endmill in a machine like a Sherline MILL may spell trouble. Some hobby sized machines have overload protection on the DC drives that they use. This is great to protect the motor and gearing of the machine but if the cutter is overloaded or the flutes rendered "toothless" due to chip welding and the operator is unaware, continuing to feed the axis while the spindle rotation is off or coasting to a stop will cause the small 1MT shank to fail. I never claim to know it all, but I have learned some hard lessons from first hand experience. My items being sold to hobby machinist are always described to the best of my ability. As a general rule, I always attempt to approach my machining problems with an open mind. Anybody who has opinions on this material is welcome to contact me, I am always interested in learning through discussion.

"Vector" forces was the term used to describe the forces acting upon the toolholder mounted in the spindle of the mill or lathe. I was not really concerned about the chuck being pulled out of the spindle taper, there's supposed to be a drawbar assembly used with this chuck. The collet chuck in question was 1MT ER25 which is fine in the Sherline lathe or mill provided certain conditions are considered. The shank of the MT1 taper has a max od of under .5". The max. tool shank the collet series can hold is 5/8". The concern when designing this type of tooling is that an inexperienced operator may overload the cutter or cause chip welding which may lead to a failure of the MT1 shank through being bent out of concentricity. Peter's orginal question was if there was a MT1 ER32 series chuck available. Designers must consider that these chucks are going to be used in mills as well as lathes. Lathes are often using tailstocks to help support the cross slide's perpendicular pressure exerted on the workpiece being held in the collet, so small shank size like 1MT is not really a problem, but designing a 1MT ER32 that is holding a 3/4" endmill in a machine like a Sherline MILL may spell trouble. Some hobby sized machines have overload protection on the DC drives that they use. This is great to protect the motor and gearing of the machine but if the cutter is overloaded or the flutes rendered "toothless" due to chip welding and the operator is unaware, continuing to feed the axis while the spindle rotation is off or coasting to a stop will cause the small 1MT shank to fail. I never claim to know it all, but I have learned some hard lessons from first hand experience. My items being sold to hobby machinist are always described to the best of my ability. As a general rule, I always attempt to approach my machining problems with an open mind. Anybody who has opinions on this material is welcome to contact me, I am always interested in learning through discussion