Thread: ER collet variations!! BEWARE

Kryn, 8 degress for the long taper and 30 degree for the short front taper are the only correct value for ER collets. It is possible that the collet itself springs open to a slightly different angle, but rest assured if put into the collet chuck it will forcefully conform to 8 and 30 degrees.

Another possibility is that the collet was used to clamp a diameter larger than the largest diameter stamped on it. Clamping an even very slightly oversize item is a big NONO as it can and will permanently damage an ER type collet. Such damaged collet can spring open to some absurd angles. Just like if you overstretch a coil spring, it will never return to its original length anymore.....

Also you mention metric and imperial ER collets. Please be aware that the ER collet series is inherently METRIC (invented by the Swiss collet maker RegoFix as a toolholding collet, and the Swiss stopped using inches in the mid 1800's). Yes they also make imperial collets, but be warned:
- Some Chinese made "imperial" ER collet are still metric, but simply stamped with imperial numbers.for example, they will stamp a 7-6mm collet as "1/4". But that does NOT mean that you can clamp anything between 6.35mm and 5.35mm. It simply means that 6.35mm can be clamped because it is smaller than 7mm and larger than 6mm.
- Some more expensive "imperial" collets are indeed made to exact imperial dimensions - with a clamping range of about 0.04" downwards. Please note that such "imperial" sets need more collets, to gap-lessly cover the same range as a metric set does.

Also take note, that whilst all ER collets are "double taper" collets, not all ER collets are also "double slit" collets. Double slit collets have 1mm clamping range, single slit collets have only 0.5mm clamping range. That said, all Chinese ER collets I have come across are double slit.

You also say one collet is very short? I take it you mean the inside clamping area is shorter than the external collet length. The outside length of all ER coolets in a series (like ER25) is always the same. But inside clamping length can be much shorter. The smaller the collet diameter, the shorter the clamping area is made. Say a 1.5mm diameter ER25 collet has only a clamping length of about 10mm, and this dimension can indeed vary between different makers (as I have found out comparing some Schaublin, Rego-Fix and Chinese no-name collet sets that I have).

There is the OZ series

http://www.amtuae.net/tsc-img/Collet-OZ-big.gif

Standard ER is 8 degrees.

Originally Posted by cba_melbourne

Kryn, 8 degress for the long taper and 30 degree for the short front taper are the only correct value for ER collets. It is possible that the collet itself springs open to a slightly different angle, but rest assured if put into the collet chuck it will forcefully conform to 8 and 30 degrees. The Vertek is the very short one (overall length) the Chinese ones are longer. Will post a pic tomorrow.

Another possibility is that the collet was used to clamp a diameter larger than the largest diameter stamped on it. Clamping an even very slightly oversize item is a big NONO as it can and will permanently damage an ER type collet. Such damaged collet can spring open to some absurd angles. Just like if you overstretch a coil spring, it will never return to its original length anymore.....
To the best of my knowledge they've not been used.

Also you mention metric and imperial ER collets. Please be aware that the ER collet series is inherently METRIC (invented by the Swiss collet maker RegoFix as a toolholding collet, and the Swiss stopped using inches in the mid 1800's). Yes they also make imperial collets, but be warned:
- Some Chinese made "imperial" ER collet are still metric, but simply stamped with imperial numbers.for example, they will stamp a 7-6mm collet as "1/4". But that does NOT mean that you can clamp anything between 6.35mm and 5.35mm. It simply means that 6.35mm can be clamped because it is smaller than 7mm and larger than 6mm.
- Some more expensive "imperial" collets are indeed made to exact imperial dimensions - with a clamping range of about 0.04" downwards. Please note that such "imperial" sets need more collets, to gap-lessly cover the same range as a metric set does.

Also take note, that whilst all ER collets are "double taper" collets, not all ER collets are also "double slit" collets. Double slit collets have 1mm clamping range, single slit collets have only 0.5mm clamping range. That said, all Chinese ER collets I have come across are double slit.

You also say one collet is very short? I take it you mean the inside clamping area is shorter than the external collet length. The outside length of all ER coolets in a series (like ER25) is always the same. But inside clamping length can be much shorter. The smaller the collet diameter, the shorter the clamping area is made. Say a 1.5mm diameter ER25 collet has only a clamping length of about 10mm, and this dimension can indeed vary between different makers (as I have found out comparing some Schaublin, Rego-Fix and Chinese no-name collet sets that I have).

It's the overall length as you will see in the pics tomorrow.

Regards and Thanks for the replies.
Kryn

I noticed this collet looked unusual. This picture is one I copied from one of Kryn's posts in my thread https://www.woodworkforums.com/showth...=191508&page=2. I even queried Kryn. It does look pretty long to me.






Dean

There are heaps of different collet forms.

It could be Ortlieb (original makers I think, but widely copied)

See http://www.ortlieb.net/en/products/c...g/collets.html

Originally Posted by Oldneweng

I noticed this collet looked unusual. This picture is one I copied from one of Kryn's posts in my thread https://www.woodworkforums.com/showth...=191508&page=2. I even queried Kryn. It does look pretty long to me.






Dean

There are many many collet systems around.

Some are for toolholding, some are for workholding, some can do both. Some workholding collets are of the dead length type, eg the workpiece does not move axially when clamped.
Some are only usable for one specific size, some cover a narrow range of sizes, some cover a large range of sizes.
Some of them are proprietary, meaning they do on purpose not follow any standard, nor fit any other machine tool - to force the user to buy at high price from the OEM.
Some of them were invented by a particular machine tool maker, but not widely adopted by others (like several Schaublin collet series).
Some of them have only ever gained wider popularity in certain regions of the world, sometimes only in certain specific countries.
Some of them have only gained popularity in very specific industries.
Some of them have simply become obsolete.
Sometimes you need almost forensic skills, to correctly identify a collet that is presented to you without the machine it is/was intended to fit.

The above is definitely not an ER collet. I would say it is a toolholding collet, designed to clamp one only specific diameter.

These are the collets in question, top right is the vertex collet, while the other one is Chinese. From what I've learnt from our friend, Google, is that the Vertex is the correct sizing for ER 25 collets. I would have thought that the Chinese would have made them the smaller of the 2, as they would be able to get 3 out of the same material as for 2 long ones???


collets 2.jpg
collets 1.jpg

You learn something everyday, sometimes it's costly. Oh well at least Australia Post keeps busy, with my returning mail.
Kryn

Kryn,

the one on the right is obviously not an ER collet!

You have to be careful where you buy collets from. It its a shop from Alibaba, and it sells 50,000 different items, mostly kitchen utensils and lighters and garden tools and lamps and chewing gum.... its the wrong shop. The seller is unlikely to know exactly what he sells, and he may have bought a very cheap liquidation lot of collets. He may have been told that its "probably" ER collets and easy to sell.

Indeed, beware

Originally Posted by cba_melbourne

Kryn,

the one on the right is obviously not an ER collet!

You have to be careful where you buy collets from. It its a shop from Alibaba, and it sells 50,000 different items, mostly kitchen utensils and lighters and garden tools and lamps and chewing gum.... its the wrong shop. The seller is unlikely to know exactly what he sells, and he may have bought a very cheap liquidation lot of collets. He may have been told that its "probably" ER collets and easy to sell.

Indeed, beware

Ha Ha. I just bought a heap of ear type hose clamps from an EBay shop called Beautyzz2009. This sort of thing happens all the time. Another store I was looking at also had a fashion inspired name. You do need to be careful what you buy from these shops.

Dean

I bought the Vertex from Minitech in QLD and the other set from fleabay Ozmestore in Adelaide.
Kryn

We're the ones you purchased called er collets or just called collets.
The only thing I see that eBay supplier selling at present are collets (imperial). To suit there mt2and 3 collet chucks.

Originally Posted by KBs PensNmore

I bought the Vertex from Minitech in QLD and the other set from fleabay Ozmestore in Adelaide.
Kryn

Vertex are made in Taiwan and are of reasonable quality for home use, well worth the price (I bought a Vertex ER35 set about 10 years ago). And Minitech know exactly what they sell, and can give excellent personal advise (I used to visit their shop when in Brisbane long time ago before eBay came to exist, and always returned with heavier luggage than when I left...).

Not sure about the other mob from eBay, but if they really sold you that set as an ER then they have no idea what they sell and you should return it for a full refund.