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

[mikey553]

You have got a better luck with the chuck and collets than me. I think I will try CTC for both chuck and collets. Maybe this time I will get a better quality.
Have you noticed that CTC precision collets do not have small sizes? It has to be a reason for that.

The problem you describe with the small collets is not actually a problem. All small sizes are done this way. A small bore does not need to go all the way, a shorter one is easier to make and it functions very well. The number of splits is also lower on small sizes because you need to preserve at least some of the bore surface. The rough bore could be a quality issue, but it also could be the burrs from slotting. You can try to clean them up.

I checked my ER-11 chuck and collets very carefully for angles, bore size, contact and runout and most of the tools were a complete garbage. Maybe Amazon sellers sell better goods?

[mikey553]

I have just ordered a set of precision collets and a chuck from CTC. They sent me a 10% off coupon R2021, which I think is good through December 31.
I'll let you know the result in a couple of weeks.

[mikey553]

I have received a set of precision collets and a chuck from CTC and thoroughly inspected them. They were not cheap, but well worth the cost. These collets came in clear cases with blue caps. The yellow cases on the photo are from the old junky set for comparison. I don't know who made the precision collets, but they deserve to be called precision. The bore, the taper, the runout - everything is correct. The runouts of the inspection pins, measured 1" away from the collet chuck in a V-block, vary from 0 to .002". This is very refreshing, especially when you compare them to the junk which came from China in yellow boxes.

Thank you DICKEYBIRD for your reference, otherwise I would not know about this source. The product was shipped from Denmark (apparently CTC has operations there) and it arrived in 2 weeks. I always share my good and bad experiences with tool suppliers and suggest we all do this. This is the only way to find a decent, but not overly expensive source.

[DaveD44]

Mikey, thanks for updating this item with your CTC experience. They took only 2+ weeks to arrive, close to what they promise. It appears that you did not purchase the smaller collets, i.e. below 2.5mm. My el junko collets are acceptable from the 2.0mm size up; it's just the 1.5 and 1.0 that are garbage. I believe if I get some from CTC it would be only those two.

And how about the chuck? It's one of the long ones? Is it also a higher quality than what you already have?

[mikey553]

Dave, I've got a short chuck 16 mm in diameter because I am thinking about milling with it. The picture is attached. It was not advertised as precision, the runout tolerance is .015 mm. But with a good collet I am measuring 0 (zero) runout on this chuck in a V-block.

Maybe I just got lucky, but my first ER-11 chuck of exactly the same size has .0015" = .038 mm runout with the same good collet. I cannot say for sure if CTC tools are always good, but so far they met my expectations.

BTW CTC does not sell precision ER-11 collets in small sizes. Small bores are only available in regular version. You never explained what was wrong with small collets, did they have big runout? See my answer in post #31 about small sizes design.

[DaveD44]

Thanks for the update, Mikey. I'm going to order a 1.0mm and a 1.5mm collet, even though they are not listed as precision; I'll take a chance since they are cheap enough. I am also ordering an ER11 chuck 10mm diameter, that I can easily grind down to 0.375 (10mm=0.394"). Hopefully it will work out.

[mikey553]

Dave,
Let me know the outcome when you receive your staff. Please include the pictures of the cases for the collets and chuck.
The best way to check the chuck and collets for runout is to put a precision pin of nominal collet diameter in the collet and use a V-block to indicate a pin. I did my checks 1" away from the collet face.

[DaveD44]

Mikey, I received the collets and 10mm chuck yesterday, ordered on 1/18 and delivered on 1/28. Not bad! They were shipped from Denmark like yours.

First impressions are the collets are beautiful. On the attached photo, the new collets and chuck are in the rear and the original cheapies are in the front. Even in this photo you can tell that they are a much better quality; first, they have six splits instead of four, and the bores are .357" deep on the 1.0mm and .465" deep on the 1.5mm, compared to .25" deep for the two originals. They are also very clean, with no evidence of polishing media or other detritus from the manufacturing process. They are also beautifully polished. Note that the slots on the old 1.0mm collet (in front) are even cut off center; also note that this collet has a hole that is really about 1.4mm in diameter, not 1.0mm. No such problems with the new ones--they are just what they say. The largest sized drill that will fit in them is 1.0mm and 1.5mm. The 1.0mm can tighten a #78, 0.016" drill, with only a slight bit of runout. All drills that I tried in both had a bit of runout, but I believe that was mostly because I had to put them in the older chuck and it has runout. But the runout was much better with both collets than with the others.

The chuck out of the box is about .25" shorter on the working end than the original after I shortened it. The new one is in the rear and you can easily see how much more compact it is. So it gets me even closer to not having to move the mill table much if at all when I switch from milling to drilling. It has a lathe center hole on the rear end; I put it in a chuck which I adapted to my cylindrical grinder to see if I can zero out the working end and I believe I can get it to a couple tenths. The tailstock end is perfect. So all I need to do is take off a few thousands for 1-1/4" or so of length on the working end to get it to 0.375 (actually, 0.3747) and then cut it off. The eccentric edge in the nut (the edge that grabs the recess on the collets and pulls them out of the taper) is ground so the collets are easier to remove. All is good!

Thus far I have zero problems with what I received. Thanks to Dickeybird to pointing us in CTC's direction. I believe we've found a winner with CTC tools!

[tomato coupe]

The runouts of the inspection pins, measured 1" away from the collet chuck in a V-block, vary from 0 to .002".

Just for reference, a collet with a runout of .002" is not a precision collet. It''s actually a pretty bad collet.

[mikey553]

Just for reference, a collet with a runout of .002" is not a precision collet. It''s actually a pretty bad collet.

Only one collet had .002" runout 1" away from the collet's face and one more had a .0015" runout. The others were .001" or better. This is measured with a collet chuck and inspection pins 1" away from the collet. I cannot argue it is not perfect, but it is light years ahead of a generic Chinese junk.

[tomato coupe]

Only one collet had .002" runout 1" away from the collet's face and one more had a .0015" runout. The others were .001" or better. This is measured with a collet chuck and inspection pins 1" away from the collet. I cannot argue it is not perfect, but it is light years ahead of a generic Chinese junk.

Jeez, how bad are the junk collets?

[mikey553]

Jeez, how bad are the junk collets?

7 mm (.2756") collet bore measured .256", 1.5 mm (.0591") collet bore measured .058" at the front and .045" at the back. Many bores had taper up to .012".
The outside taper on ER-11 collets should be 16 degrees. Most of the collets were off on taper angle, the 4.5 mm collet measured almost 19 degrees.
I did not measure the runouts and I hope you understand why.

I confronted both sellers and received full refunds, but I waisted my time dealing with them. One of the sellers was Banggood and I have never received a decent collet or chuck from them. They were all 100% defective. I no longer buy precision staff from them regardless of the price.