Author Topic: extended range of ER collets  (Read 1091 times)


Offline Admiral_dk

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Re: extended range of ER collets
« Reply #1 on: January 13, 2024, 02:27:13 PM »
Thank you Zephyrin  :ThumbsUp:

I have just ordered ER40 in the following sizes 27, 28, 29, 30, 31 & 32mm.  :)

They should be handy in the Lathe - time will tell how accurate they are ....

Per      :cheers:

Offline Laurentic

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Re: extended range of ER collets
« Reply #2 on: January 14, 2024, 12:57:45 PM »
 Like Per, I have also just ordered from this supplier, ER32 21-22-23-24-25-26, delivery apparently just 12 days away.

Also like Per, no idea whether they are accurate or not, but for under £18 delivered they were worth a punt.  Those are handy sizes, I'm sure they will be of some use!!!!

Time will tell if it was worth it or not!

Chris.   :ThumbsUp: :ThumbsUp:

Offline Jasonb

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Re: extended range of ER collets
« Reply #3 on: January 14, 2024, 01:09:02 PM »
I've put a 12.75mm ER16 into my basket and one of the Er32 sizes that may come in handy. The ER16 will be useful for holding my 1/2" shank electronic edge finder and save having to put the ER32 holder into the machine.

On the way at the moment I have a couple of ER16 in half sizes which means less closing down when gripping drills so the 3.5mm and 4.5mm will come in handy for 3.3 and 4.2mm taping drills.

Offline Krypto

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Re: extended range of ER collets
« Reply #4 on: January 14, 2024, 04:02:06 PM »
All right, you got me! I ordered the ER32 set (21-26mm).  While the cheap ER11 collet set I have is complete trash, I've always had good luck with no-name ER32 collets in the past. I'm not expecting a whole lot with these, but I use these collets primarily for work holding (lathe chuck, hex & square collet blocks) and a few times a slightly larger size would have come in handy.

This is a good time to order as it's a few weeks until the Chinese new year.
My Workshop Blog:  https://doug.sdf.org/

Offline uuu

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Re: extended range of ER collets
« Reply #5 on: January 23, 2024, 03:11:06 PM »
I've bought a set of the extended ER25 collets.  17,18,19 and 20mm.  I've not tested for runout - but now I have then I see how they work.  Each larger size is a little shorter than the previous one, so the skirt doesn't quite become a knife edge.

Depending on how long the taper is in each chuck, an oversize bar will enter the collet, but may not pass all the way through, as it may foul the chuck.  My lathe chuck will cleanly pass 17mm, and 18 only just, but 19 and 20 would have this limitation.

So, for example, to hold a 3/4" threaded end mill, I'd not get it far enough in to be clamping cleanly on the smooth bit.  And as the collet is quite short it will stick way out, I'd not trust it for full-fat milling.

Nevertheless, for the price I'm happy.  There will be one or two stubs of material that the collet will hold better than a three-jaw - and as noted, hex and square collet blocks will hold a bit more.

Wilf

PS - Talking of half-step collets - I have bought an imperial 1/8" ER25 collet.  It's much more secure than a 4mm one for the shanks of PCB cutters.
« Last Edit: January 23, 2024, 03:19:53 PM by uuu »

Offline Jasonb

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Re: extended range of ER collets
« Reply #6 on: January 23, 2024, 04:27:59 PM »
I've got imperials for the common shank sizes in all my collets ER16, 25 and 32. The 1/8ths get used the most with spot drills, ctr drills & engraving cutters and the 1/2" for my edge finder. I Don't fnd myself using imperial shank cutters much these days.

Also got some half sizes in metric such as 2.5 3.5 and 4.5 which don't need closing down so much on 2.5mm, 3.3mm and 4.2mm tapping drills

Offline Krypto

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Re: extended range of ER collets
« Reply #7 on: February 19, 2024, 03:00:34 AM »
I did some QC testing on the extended range ER-32 collets I purchased from the Aliexpress vendor E&Mill as mentioned by Zephyrin.  I was pleasantly surprised on how well they performed.

First off, the collets came individually boxed and packaged in a thick foam shipping package. The collets were clean with no chips, sharp edges or other problems.  They looked good.

The first pic shows were I turned down an aluminum bar between centers on the lathe. This way I could easily turn down the bar in increments and then test each collet. The bar was long enough to engage the entire collet and still have enough room on the outside for measuring. I started with a 1" scrap bar so I couldn't test the 26mm collet.

The second pic shows the test rig. A few weeks ago I bought a 5C Spin-indexer which now has the based milled down to use in the milling vise. It's for quick jobs when I don't want to break-out the 8" rotary table. I don't own any 5C collets and will always be using a 5C-ER32 adapter as shown.  From previous measurements, I'm getting around .0005" run-out with the Spin-indexer measured with a plug gauge in an ER-32 collet.  I don't consider that bad with using an adapter and plenty good for it's intended use.

Measurements were taken with the spindle locked and in quarters (0, 90, 180, 270) with the highest TIR recorded.

In the third pic shows the measurement of the 25mm collet at .0005" TIR. I expected more and since this sensitive .0001 indicator makes all my equipment look like junk I don't use it much, so I compared the readings with my front line .0005 test indicator. It was the same! Turns out this was actually the worst TIR of the bunch.

25mm collet.0005" TIR
24mm collet.0004" TIR
23mm collet.0002" TIR
22mm collet.0003" TIR
21mm collet.0003" TIR
20mm collet.0002" TIR(From my original imported ER-32 collet set)
3/4" collet.0003" TIR(Imported but sourced from industrial supplier Maritool)

Comments:

Yes, I use metric ER-32 collets even though I use the fractional system. I have some fractional collets in regular sizes.

A Spin-Indexer isn't the most precise thing in the world.  Even though I tried my best, there's going to be a few tenths of variance.

I was expecting out-of-spec sized collets to have more run-out, instead these seems to be at least as good as the ER-32 collets I've been using.

I'm impressed enough with these that I'm going to spin the wheel and buy a set of ER-11 collets from the same vendor, E&Mill, to replace the crap set I have now. I'll order them in a few weeks after the big new year holiday in China has calmed down.
My Workshop Blog:  https://doug.sdf.org/

 

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