ER collets

Do ER(25) collets provide a good grip for holding drill bits as well a

endmills?

Brenda

-- anotheri

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anotherid
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Yes,no problem. Use mine all the time like that in the mill.

Alla

-- Allan Waterfal

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Allan Waterfall

There has been a discussion some weeks ago here. Yes, they do. At __very__ heavy cuts, mills do get pulled out. But generally nothing to get worried about.

Nick

Reply to
Nick Müller

This old chestnut keeps doing the rounds, and it simply is NOT true. Every toolroom I've worked in has used ER collets (gradually being replaced by shrink fit these days). We take cuts that would stop most knee mills dead on our machining centres without problems. When things go wrong and we take a larger cut than planned it's always the cutter that breaks before the collet lets go.

In reality this is simply not likely to be a problem -as long as you've tightened it up of course.

Regards Kevin

Reply to
Kevin Steele

My experience is different: 20mm rough cutter, 20mm deep full cut pulls it out. Collet was closed 'till the thread water dripped out. Collet is Fahron ER32, mill is Deckel FP1. YMMV.

Nick

Reply to
Nick Müller

I have to say my experience has been nearer to Nicks' than Kevins. I fou= nd my=20

14mm end mill was cutting depths all over the shop in my ER32 collet chuc= k. I=20 don't know if the quality of the CC makes a difference, but I was able t= o get=20 round the problem by tightening it as hard as it'd go (not helped by the = fact=20 there's no spindle lock on a Warco VMC).

--=20 Boo

Reply to
Boo

I did say you have to tighten them up. If your collet body hasn't got any way of holding it with a spanner while you tighten the nut I'd try and machine some flats on it.

Regards Kevin

Reply to
Kevin Steele

I've had cutters pull down when using ER32. There are special low-friction or ball-bearing 'milling nuts' available to enable extra tightening, I've never seen one in the 'flesh'. If I know there are heavy cuts to be made, I'll use an Autolock or sidelock if I have the cutter to fit.

Going to the other extreme, I got some ER40 collets off ebay recently which have been used in a tool grinder. One of the snags with ER for workholding is that there is an inaccessible length right against the collet, because of the nut. These collets have grinding marks on the face, I reckon the outer face of the nut must have been ground away completely. There would still be enough strength, I suppose, for tightening for grinding operations but perhaps not enough for milling or turning.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Reply to
Tim Leech

Interesting. So how much pull-out/pull-down have you all had? Bearing in mind that on heavy cuts, ie depth of cut=cutter diameter, these are roughing cuts only, and of course there is ample material left for a finish cut, what sort of effect are we talking here?

I used the ER's almost exclusively on my VMC as it was easier to change these collets over without a spindle brake than the R8's, but of course never took really heavy cuts on that machine.

On the Bridgy I find that I've gone back to using the R8's more than the ER, and have done a few heaving roughing cuts - full depth on a

16mm - and not had a pull-down so far. Mind you I don't feed it too aggressively and these have been hand rather than power fed as it's a lot easier to feel whats going on with the cutter.

I should add that I'm looking for others direct experiences here rather than arguing what's best.

Peter

Reply to
Peter Neill

A few mm over say 200mm cutting length.

Not enough left for a finishing cut. That's why I don't forget that lesson. :-)

The rough cutters I use can't be feed by hand (yes they can, but it would be an exercise). They need a high feed rate and they get so silent when they get what they ask for. They are called "soft cut" and that is true! Even my mill that is quite noisy only whispers with them.

Me too. Just telling my experience. I know that others do get other results and I accept them. There are enough parameters (like the collet closing nut) to have different results. Despite the lesson learned, I like my ERs.

Nick

Reply to
Nick Müller

I use ER 32 collets with 3/8 and 1/2 4 flute carbide end mills 1 to

1.25 inches depth of cut with 0.015 to 0.030 step over at 350 SFM and 0.0015 to 0.002 IPF cutting tool steels at 60 Rc. without a problem. Use quality collets, holders, and end mills, make sure they are clean, no oil film. Even though ER collets work well over a wide size range compared to R8, or 5C for best results get a collet that is exactly the size of the tool. ____________ Andre' B.
Reply to
andre_54005

Since it seems to be agreed that ER collets are a good thing, how do

choose a set?

I can see an ER25 set from Warco for £99. The collets have a range o

2mm.

From Chronos I see a set for £190! The collets however look to have range of just 1mm.

From the previous post, I presume that the 1mm collets will be better But is it worth paying all the extra to get that? My mill is a Warc WM-16 (3/4 HP), so relatively light cuts are all I can take.

Any other suggestions for where/what to look/for? I did find a plac called (I think) Axminster and requested a catalogue from them, bu nothing ever turned up so I gave up on them.

Brenda

-- anotheri

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Reply to
anotherid

1mm smaller is the normal capacity. The smaller ones even just 0.5mm. You should obey that, or you ruin them.

For a mill, you only need the following sizes:

6mm, 10mm, 12mm, 16mm and 20mm. (ER25 has 16mm as the biggest one) These are the diameters of the mill's shafts. Even reamers do have shaft diameters in 1mm increments if you buy the right ones. You might want to use the collets on your lathe, so go for quality and not for bargains.

If you want to do drilling in your mill, you might consider buying a drill chuck. Or slowly add the collets you need. For my ER32 I am far away from having a complete set and can well live with what I have.

Nick

Reply to
Nick Müller

Just picked up a couple of sets of ER16 collets from CNC Tooling Systems

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was right ;)

Arc Euro have some nice packages for ER25

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Reply to
Lester Caine

Brendan

Have a look at the ArcEuroTrade website under colletts, they offer limited sets that cover the basic range that Nick has identified for about =A370 includng a collett chuck, with individual colletts at about =A35-7. I personally feel that colletts with a range over 1mm would be pushing the limits of the material.

Although I have a full set of ER32 by Vertex which are superb I also have several individual (un-named) colletts from J&L and ArcEuroTrade, I cannot see any differece in their performance. The only issue that strikes me about a part set is that you will be limited in what size drills you can use and being able to swap between cutters and drills is a major advantage for me. A full set of ER32 covers 2mm - 20mm range and ER25 covers up to 16mm. Have a look for show offers I suspect that even Chronos will be cheaper than you quote at the Midlands exhibition, I think I paid about =A3150 for the full set with chuck and spanner.

Best regards

Keith

Reply to
jontom_1uk

As far as I know, all the ER collets, except the very small ones, increment in steps of 1mm. Least ways, both my ER16 and ER32 sets do. My ER32 boxed set is made by Vertex and I got it for a very good price from RDG Tools of Hebden Bridge

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disclaimer - I live almost 200 miles away.

Reply to
lemel_man

That's exactly why I want them! I have a drill chuck, but it's a hassl removing it when I want to use a mill, especially as sometimes th drawbar seems to get well and truly stuck in the arbour and I have t hammer the spanner I'm using to undo the drawbar to get it to turn. I' worried that this is not doing the drawbar any good at all! So, I'd lik to fit a collet chuck and mostly leave it in place, yet still be able t switch between drills and mills (and edge-finder). Looks like I may b stuck with going for a "full" set.

Brenda

-- anotheri

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-- anotheri

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You will see them at most of the shows. They were at Bristol this weekend ;)

Reply to
Lester Caine

You really don't have to tighten it that much. A short lever (and no second key) is enough. You do have MT? It is self locking.

Of course it is better to have a full set. :-) Edge finders do have a 10mm shaft.

Nick

Reply to
Nick Müller

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