ER16 Collets from Ebay

[SillyOldDufferModerator @sillyoldduffer]

Posted by Calum Galleitch on 15/04/2022 23:37:26:

… They aren't great quality but for their purpose – workholding in the wood lathe – they are ideal. …

Can you define exactly what you understand by 'great quality' please Calum? It's a hobby horse I know, but in engineering 'quality' is meaningless without a specification.

And the specification is important, otherwise folk waste money on tools they can't benefit from! Like fitting an expensive telescopic sight to a Brown Bess Musket, or a Formula 1 pre-selector gearbox to my Eco-Corsa.

For example, I could buy a set of:

• high-rpm collets guaranteed concentric to 0.002mm in all sizes. Bonkers on my hobby milling machine, with it's bendy frame, ordinary bearings, spindle, MT-taper, and inexpensive collet chuck. Sooper-dooper collets don't help : they only pay off on a heavy high-speed well-maintained precision machine. As far as I know, no-one on this forum owns a machine in that league.
• mid-range rpm collets guaranteed concentric to 0.005mm in all sizes. These are still over the top on my machines, and I think the number of Model Engineers who could make good use of them is almost nil. They require a heavy precision machine in good order, low wear throughout, and properly adjusted.
• standard collets less than 5000 rpm, concentric between 0.015 and 0.02mm with increasing diameter. These might be worth the money.
• unspecified collets are sometimes bad enough to introduce noticeable error on a hobby machine. The two sets I own don't! They're as good as they need to be, that is error of the whole set-up, from spindle to tool shank, just shows up on an inexpensive Dial. As the error is lower than my ability to measure it, there's no point in me wasting money on well specified collets.

An ER collet would have to be extremely badly made for the error to matter on a wood lathe!

I suspect many 'quality' tools are bought by hobbyists because they're objects of desire and an emotional prop, not because they do a better job! Although well-made tools in good condition are easier to use, it's amazing what people do with simple equipment in middling order,

Dave

[CalumParticipant @calumgalleitch87969]

Posted by SillyOldDuffer on 17/04/2022 11:29:08:

Posted by Calum Galleitch on 15/04/2022 23:37:26:

… They aren't great quality but for their purpose – workholding in the wood lathe – they are ideal. …

Can you define exactly what you understand by 'great quality' please Calum? It's a hobby horse I know, but in engineering 'quality' is meaningless without a specification.

Well, I haven't measured them, but they came without any specification, and at least one of them has a slit where the slitting operator got about halfway through, was interrupted for some reason, and started again leaving a very obvious ledge of saw kerf. Once the ER collet for the big lathe is done I will try indicating a few with some circular ground stock and see how bad they really are!

[B TulleyParticipant @btulley]

Posted by B Tulley on 15/04/2022 20:06:16:

An update:

I purchased these from Amazon:

Collets, ER16 Spring Collet Set ER16 1-10mm Elastic Collet Chuck Set Chuck Collet for CNC Engraving Machine & Mill Turning Tool, 1-10mm, 10PCS : Amazon.co.uk: DIY & Tools

(I paid £21-86)

Whilst I've yet to check the runout the finish is fine – no signs of any burrs or swarf. I'll keep you posted.

Edited By B Tulley on 15/04/2022 20:07:30

 

An update to the above, as promised……

I checked the runout of the 6, 8, 9 and 10mm collets yesterday; the collets were held in one of these:

C12-ER16A-100L Metal Collet Straight Shank Chuck Holder CNC Milling Tool | eBay

(It was £5.99 when I bought it a few weeks ago!!)

– which in turn was held in an ER32 Collet fitted to a virtually brand new Chinese Clone Bridgeport (so zero wear).

I fitted the appropriate size of drill bit into each collet in turn and measured the runout on the drill shank using a 0.001" Dial Gauge; the worst was 0.005" and the best was 0.002".

I'll have that, thanks very much

A Happy Bunny.

Edited By B Tulley on 22/04/2022 17:10:16

[JasonBModerator @jasonb]

Well I suppose you get what you pay for and if you are happy with that and it's for holding drills then all well and good.

I'd be looking for more like 0.0005" half a thou which can be had for not a lot of money.

[Anonymous]

Posted by B Tulley on 22/04/2022 17:08:57

I checked the runout of the 6, 8, 9 and 10mm collets yesterday; the collets were held in one of these:

C12-ER16A-100L Metal Collet Straight Shank Chuck Holder CNC Milling Tool | eBay

– which in turn was held in an ER32 Collet fitted to a virtually brand new Chinese Clone Bridgeport (so zero wear).

I fitted the appropriate size of drill bit into each collet in turn and measured the runout on the drill shank using a 0.001" Dial Gauge; the worst was 0.005" and the best was 0.002".

 

… and what torques did you use on the collets?

Edited By Peter Greene 🇨🇦 on 22/04/2022 19:11:41

[B TulleyParticipant @btulley]

Posted by JasonB on 22/04/2022 18:51:40:

Well I suppose you get what you pay for and if you are happy with that and it's for holding drills then all well and good.

I'd be looking for more like 0.0005" half a thou which can be had for not a lot of money.

Ah, you have a point – I was getting confused between mm and inches….

So my 0.005" (worst collet measured) equates to 0.127mm; Arceurotrade sell 0.015mm (0.0006&quot collets in a set (12 collets – I got 10) for double what I paid. Was any of the runout measured due to the way I was doing it – almost certainly, because I had a collet holder (ER16) held by another collet holder (ER32) so twice the opportunity for runout to be introduced. Not sure how else I can check the collets though?

[JasonBModerator @jasonb]

Sounds like a bargain 10 times as accuracy for less than twice the price

Also the same opportunity for errors to be halved just as much for them to be doubled with the multiply options for runout.

Assuming the er16 stayed in the other chuck then you still have a 3thou difference between collet, that's 75 microns which is a magnitude of five times worse than the 15 micron ARC ones or 9 times the 8 micron ones

Edited By JasonB on 22/04/2022 21:07:26

[B TulleyParticipant @btulley]

… and what torques did you use on the collets?

Edited By Peter Greene 🇨🇦 on 22/04/2022 19:11:41

Sorry – no idea I'm afraid; They were just pulled up "tight" but without leaning on them…..

[Anonymous]

The recommended torques given by prime manufacturers – at which they quote their runout figures – are pretty high. Much more than you can apply with the little 6" wrench normally supplied with the collet holder and by the sound of it considerably more than you were using.

Not sure how representative your numbers are.

My own guess is that you don't need to tighten them to the extremes given by the manufacturers but you do need to seriously tighten them (so that you feel you've done some work and knock off for a cuppa).

 

(This has been discussed in this forum a number of times if you want to do the search).

Edited By Peter Greene 🇨🇦 on 23/04/2022 01:43:59

[not done it yetParticipant @notdoneityet]

Cheap? Expect reduced end mill life if used for milling. I expect drilling with very tiny drills might be problematic and clearly hole sizes may well suffer wrt that expected.

If/when you use these for end milling, how will you know whether it is the cheap end mills or the cheap holders or the cheap chuck or the cheap machine that is causing the problems.

I might suggest that you may well suffer ‘chatter’ problems with those reported run-outs. It may not be so very noticeable, but surface finish might be an issue – as well as accelerated cutter wear.

[JasonBModerator @jasonb]

Actually torque for an ER16 is considerably less than for the bigger ER32 sizes something in the region of 40%

[Dave SParticipant @daves59043]

And varies with collet clamping diameter as well as collet size.

Useful link to regofix doc: **LINK**

Dave

[Graham MeekParticipant @grahammeek88282]

Posted by B Tulley on 22/04/2022 20:46:05:

. Not sure how else I can check the collets though?

When I recently made a new spindle for my Proxxon milling machine, (posted elsewhere on the Forum). Knowing whether any run-out I was getting at the spindle was due to the Collet, or my workmanship, was a primary requirement. I checked the collets before hand in the following manner.

A ground dowel of nominal collet diameter was gripped in the lathe collet chuck. The dowel was checked to see if it was parallel to the lathe centre-line, in the vertical plane. The subject collet was then placed over the dowel and abutted against the collet holding the dowel.

A DTI was then set to indicate on the cone diameter and the collet rotated by hand whilst gently urging it against the "holding Collet". The collets I had obtained from Arc showed no signs of error with my 0.002mm division clock.

Admittedly this does assume the two end faces in contact are perfectly square. However if this is this problem it will show by a progressively low spot reading. At both locations of the clock on the cone diameter. Turning the collet end for end on the dowel should eliminate this sort of error. If it persists then I would say the error is run-out

When I installed the new spindle and checked with one of my collets. Using the same dowel, and DTI, TIR was less than one division on the clock. Which for milling is good enough for me.

Regards

Gray,

[Anonymous]

Posted by JasonB on 23/04/2022 07:01:50:

Actually torque for an ER16 is considerably less than for the bigger ER32 sizes something in the region of 40%

 

70 vs 170 NM max according to my records so pretty close. (Recommended is 80% of that.) You can do your own conversion …. you're probably more used to it than I am on this side of the pond.

… but unless the tests are made using at least reasonably appropriate (and repeatable) torques the runout results are not particularly meaningful.

Edited By Peter Greene 🇨🇦 on 23/04/2022 17:49:03

[Nick WheelerParticipant @nickwheeler]

I would be amazed if anyone is tightening ER16 collets to 70Nm in their home workshop. Much the same applies to correctly torquing ER32s

[B TulleyParticipant @btulley]

I wonder how many of us would have the tooling to be able to tighten an ER Collet Chuck to a specified Torque as well? Whilst I have Torque Wrenches for use with Sockets I don't have Torque Spanners.

[DiogenesIIParticipant @diogenesii]

Can anyone provide a link to documentation illustrating how concentricity diminishes with lower values of tightening torque, please?

[Neil LickfoldParticipant @neillickfold44316]

The collets I have that have claimed runout values of less than 0.008mm and 0.005mm have been very good, from ER11to ER40 collets. The best has been seen on the cnc router where cutter life was extended and a much better surface finish too. I don't pay too much attention to the torque of the nut. I do test the nut on the assembly with a known test piece of carbide to see the runout. I have found many bad nuts, and some I have repaired. Others I have thrown away. The ER brand of nuts have all been very good and I have never seen issues with them.

Neil

[Anonymous]

Posted by B Tulley on 23/04/2022 20:55:50:

I wonder how many of us would have the tooling to be able to tighten an ER Collet Chuck to a specified Torque as well?

Me too. But how much value are runout measurements if you don't torque to the manufacturers' specs.?

Like I said, it's been discussed before here several times.

I (think I) vaguely recall someone (possibly Neil) doing a MEW article on this a year or two ago but I'm not sure.

[Anonymous]

Posted by Nicholas Wheeler 1 on 23/04/2022 20:31:32:

I would be amazed if anyone is tightening ER16 collets to 70Nm in their home workshop. Much the same applies to correctly torquing ER32s

Again, me too but …

[Nick WheelerParticipant @nickwheeler]

Posted by B Tulley on 23/04/2022 20:55:50:

I wonder how many of us would have the tooling to be able to tighten an ER Collet Chuck to a specified Torque as well? Whilst I have Torque Wrenches for use with Sockets I don't have Torque Spanners.

If the tool in the collet is short enough, you could use a deep socket.

A crowsfoot spanner on your torque wrench and a simple calculation also works. As does welding a scrap socket a known distance along a spanner. But these are working mechanics techniques, so probably aren't technical enough for model engineering…

[Anonymous]

Posted by Nicholas Wheeler 1 on 23/04/2022 23:27:49:

Posted by B Tulley on 23/04/2022 20:55:50:

I wonder how many of us would have the tooling to be able to tighten an ER Collet Chuck to a specified Torque as well? Whilst I have Torque Wrenches for use with Sockets I don't have Torque Spanners.

If the tool in the collet is short enough, you could use a deep socket.

A crowsfoot spanner on your torque wrench and a simple calculation also works. As does welding a scrap socket a known distance along a spanner. But these are working mechanics techniques, so probably aren't technical enough for model engineering…

Also, lets not forget that these collets were designed for industrial use not for model engineers. If the requirements for their use are onerous in this latter context, it's up to the ME to adapt.

[HopperParticipant @hopper]

Posted by Nicholas Wheeler 1 on 23/04/2022 23:27:49:

Posted by B Tulley on 23/04/2022 20:55:50:

I wonder how many of us would have the tooling to be able to tighten an ER Collet Chuck to a specified Torque as well? Whilst I have Torque Wrenches for use with Sockets I don't have Torque Spanners.

If the tool in the collet is short enough, you could use a deep socket.

A crowsfoot spanner on your torque wrench and a simple calculation also works. As does welding a scrap socket a known distance along a spanner. But these are working mechanics techniques, so probably aren't technical enough for model engineering…

I'll raise you one technique even lower, and say that you don't need to do a calculation when adding an extender or crowsfoot etc to a torque wrench. Simply set the crowsfoot or extender at 90 degrees to the handle of the torque wrench and use the original specified torque setting. (Source: Snap-On Tools instructions for using their torque wrench extensions.)

So it could be a simple matter of drill and then file a square hole in the handle of the ER collet wrench and hook your torque wrench up to it at 90 degrees.

But I seriously doubt a correct torque setting will correct the OP's 5 thou runout. And I suspect torque wrenches on collets are overkill in the home workshop. Maybe do it once and get a feel for how tight it is and what sort of extension is needed on the original collet spanner to achieve it and then carry on by "tradesman's calibrated arm".

[JasonBModerator @jasonb]

And if you do decide to use a torque wrench then use a set of figures that are correct for your nut, you will not need to apply such a high setting for a bearing nut as a plian one.

Simple Hass chart for low friction nuts, ER16 is 40% of ER32, maybe Peters figures are for plain nuts as they are higher?

I'll just stick to using a spanner (shorter handle for the ER16 one) 

Edited By JasonB on 24/04/2022 07:05:51

[HopperParticipant @hopper]

And that's with a low-friction ball-bearing nut? Wow. Getting up there for the ER32 at 100 Ft Lbs. That's Harley engine sprocket nut torque and usually needs the long handled 1/2" drive torque wrench. The ER16 at 40 Ft Lbs should be doable with a six-inch collet spanner and both hands.

[Author]

Posts