Using an ER11 collet chuck on long shank as a small drill extender

[BCRider]

The video on YT came up today as a suggestion. Clearly I watch too many machining and tool videos....

Quick Tip: ER11 collet chuck for drilling holes in tight spots - YouTube

Anyway it answers a couple of options. First is that it can be used as the extension shown in the video. Second is that with the right set of collets it would permit holding very small drill bits that don't normally fit into some regular size chucks. I'll have to go do some "shopping" to see what options are out there but for the low cost of an ER11 chuck on a longer shank I can see this being a worthy option.

In fact it might answer THREE situations. If I were to get a metric R8 collet to hold the shank I'd be able to also use it as an adapter for very small end mills. My present R8 set only goes down to 1/4".

[mattthemuppet]

There are lots of extensions out there that use, I think, DA style collets as well as size specific drill extensions. You can get them down to really teeny tiny diameters. I have a whole box full of them from a machine shop auction that I'll need to off load at some point

[JRouche]

I didnt watch the vid. I like an ER collet extension to be not more than 6"

Matt brought up a good point, the DA collets. They can be smaller and hold very well. I have 6" DA holders that will take a very small collet. And they run just as true, IMO. JR

[mikey553]

I have an ER11 collet extension and 2 full sets of metric collets. The extension and both sets of collets are a complete junk. Huge runouts, wrong collet sizes, tapered collet bores, wrong taper angles on collets and extension, etc. Definitely not usable for small drills. Both collet sets were obtained from different sources, but they all came in little yellow plastic boxes. They did not cost much at all and you know that you usually get what you paid for. Who knows, may it was just my bad luck...

There is a better idea for drilling small holes on a mill. I've got a small DC motor, running up to 12000 RPM. I also bought a set of five 0-4 mm drill chucks. One of them is actually running true and I was able to put it on the motor shaft end. This motor has a decent power and speed is adjustable by changing the supply voltage. In the near future I am planning to make an adapter to attach the motor to the quill.

If you need an extension to reach deep inside a part, then ER11 collet extension may be the answer. It can be used for light milling as well. But get yourself a quality set, don't repeat my mistake.

[BCRider]

It's good to know that the quality is spotty on the cheap sets. That wasn't something I'd figured on.

I don't think the DA collets are a reasonable home/hobby option. Or at least not one that I need badly enough to pay the price. It looks like it would be a few hundred to get into a smaller series DA setup with a chuck or two.

[DICKEYBIRD]

Hiya Bruce, CTC Tools are good! No free shipping & a couple weeks shipping time but their stuff is very good and worth the wait. Their precision collets are reasonaby priced as well.

https://www.ctctools.biz/er11-10mm-x...let-chuck-l29/

https://www.ctctools.biz/er11-collet...ce-10-pcs-p31/

[old mart]

I got an er8 with a straight 10mm shank to hold smaller drills which are too short for the Proxxon sharpener.

[JRouche]

It's good to know that the quality is spotty on the cheap sets. That wasn't something I'd figured on.

I don't think the DA collets are a reasonable home/hobby option. Or at least not one that I need badly enough to pay the price. It looks like it would be a few hundred to get into a smaller series DA setup with a chuck or two.

I didnt hear what size you wanted? 1/2" shank? Thats all I have. Small stuff for the DA, As it should be. JR

[tomato coupe]

It's good to know that the quality is spotty on the cheap sets.

I’m shocked! Shocked!

[BCRider]

I don't actively need one. But looking up the cheapie imports it would cost me $20 for the extension chuck with 12mm shank and another $36 for a set of collets. That would cover me for about 0.6 to 0.7mm using the 1mm nominal size collet up to 7mm max collet size.

Really though I've also got two of the little chucks that used to come on the Dremel tools for a while. They stopped supplying them because they supposedly were not concentric enough. But the ones I have are good. Actually I believe that Dremel still sells them.

I could make up a threaded extension for such a chuck and that would give me what I want for up to 5/32". So do I need the ER11 extension and collets? Nope. But it seemed like a slick idea if the parts were made accurately enough.

[mikey553]

I don't actively need one. But looking up the cheapie imports it would cost me $20 for the extension chuck with 12mm shank and another $36 for a set of collets. That would cover me for about 0.6 to 0.7mm using the 1mm nominal size collet up to 7mm max collet size.

Really though I've also got two of the little chucks that used to come on the Dremel tools for a while. They stopped supplying them because they supposedly were not concentric enough. But the ones I have are good. Actually I believe that Dremel still sells them.

I could make up a threaded extension for such a chuck and that would give me what I want for up to 5/32". So do I need the ER11 extension and collets? Nope. But it seemed like a slick idea if the parts were made accurately enough.

I have just tried to clamp a 0.6 mm drill in 1 mm collet I have. It would hold it, but barely and the runout is practically a guarantee that you would break such drill in no time. Have you noticed that CDC close tolerance ER11 collet set starts from 2.5 mm, but regular collets start from 1 mm? I guess it is difficult to make a good small size collet... I may decide to get collets and extension from CDC based on Dickeybird recommendation. In addition to drilling light milling in close quarters could be made possible.

On the other hand my 3-jaw keyed 0-4 mm drill chuck has no trouble holding 0.5 mm drill and probably would go as low as 0.3 mm. Running this chuck with DC motor shows no visible runout on a 0.5 mm drill. I bought a set of 5 chucks from Banggood a few years ago, but only one chuck was good enough for small drills. It looks like a regular keyed chuck, but smaller in size. I have a couple of Dremel tools, but don't have a chuck, so there is nothing to compare.

[Fasturn]

Dont laugh.... I just made one out of 1/2 alum. 1/8 bore with set screw. I use PCB drills alot. Easy in and out with high quality carbide. Also use a 200 DA for bigger stuff. Just dont use it alot so Alum is fine. I told you NOT to laugh !!

[BCRider]

Fasturn, I'm smiling, not laughing. For drills like that which are so lightly loaded holding the shanks in an aluminium holder would work fine. I think you'd be at more risk of bruising the holder with how you hold it on the other end. You're more likely to bruise the aluminium when you grip it in your big drill chuck.

Mikey, I saw your previous post and looked up some chucks on Amazon. I only found THESE 0.3 to 4mm CHINESE IMPORTS that come with a little brass adapter to permit fitting to a motor with a 1/8 shaft. Does this look anything like your Bangood chucks?

[mikey553]

BCRider, yes, this chuck is very similar to mine. I have attached a link to a Banggood motor with chuck: https://usa.banggood.com/Machifit-77...N&rmmds=search
My setup is very similar, but I have made my own adapter from a brass rod. The motor shaft is 5 mm, the chuck has No. 0 Jacobs taper. To eliminate any runout on the adapter I have made the bore for a shrink fit to the motor shaft, then clamped the motor body in the lathe chuck, powered the motor and turned the adapter's matching Jacobs taper on a lathe. The little motor has plenty of power and rigidity for that.

If you search Banggood, you may find separately chucks and motors. They are very inexpensive. Ignore their adapters, I cannot imagine they can be any good.

[Paul Alciatore]

I have a set of ER-11s in 1mm increments. All but the 1mm one do cover a full 1mm range. I have used them on things like 1/8" diameter end mills. The 1mm one only goes down to about 0.5mm but I haven't tested that. I think it has something to do with the width of the saw cuts vs the amount of the original 1mm bore that is left after sawing. And, of course, the accuracy with which those saw cuts are located on the center axis of the collet. While it may be possible in theory, it is going to take a really good manufacturing process to go down to near zero in the 1mm size ER-11 collet.

For small size drill bits the ones with the 1/8" shanks, sometimes called circuit board drills, may be a good idea instead of trying to grip a shank in the below 1mm range. They are also easier to handle.Fasturn showed some in post #12 above.

I have just tried to clamp a 0.6 mm drill in 1 mm collet I have. It would hold it, but barely and the runout is practically a guarantee that you would break such drill in no time. Have you noticed that CDC close tolerance ER11 collet set starts from 2.5 mm, but regular collets start from 1 mm? I guess it is difficult to make a good small size collet... I may decide to get collets and extension from CDC based on Dickeybird recommendation. In addition to drilling light milling in close quarters could be made possible.

On the other hand my 3-jaw keyed 0-4 mm drill chuck has no trouble holding 0.5 mm drill and probably would go as low as 0.3 mm. Running this chuck with DC motor shows no visible runout on a 0.5 mm drill. I bought a set of 5 chucks from Banggood a few years ago, but only one chuck was good enough for small drills. It looks like a regular keyed chuck, but smaller in size. I have a couple of Dremel tools, but don't have a chuck, so there is nothing to compare.