Question regarding prices for ER collets.

bartmes

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May 20, 2012
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I understand that you generally get what you pay for in life but I'm wondering if that's really true with regard to ER collets. I have an inexpensive set of ER16 collets in metric sizes, several of which seems to clamp unevenly so I began shopping for a replacement set. There's a huge range of prices-from under $20 to over $400. I'll probably go with something in between but is there really a measurable difference in accuracy with a set costing, say $75 vs. a set costing $250? Country of origin (China vs. USA vs. Germany) has an impact, as does the source (general online retailer vs. industrial supplier) but the wide difference is still puzzling. Comments appreciated.
 

Schatznut

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I just bought a set of ER16 collets, with the probability that I'll only use the two or three smallest sizes. I've tried the .5-1 and the 1-2 so far and found that I needed to put a small amount of grease on the collet holder bore and the inside of the collet nut to allow the collet to pull up fully and evenly, as well as to get the collet out of the holder. Because I didn't know if my experiment would work (using this in a larger lathe), I spent as little money as possible. I've not been disappointed but I have found that I need to support the free end of the piece I'm clamping with a precision chuck in the tailstock while tightening down the collet nut to get it to run true.
 

Dr. Jon

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The prices depend on whether they are American or Chinese made. I expect teh American made ones have less run out. Before paying for this I suggest that the run out of the tool to use on be checked. If the tool such as a lathe already has a lot of run out a cheap er collet will probably be fine.
 

MARK A. BUTTERWORTH

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It seems to me as a supplier that the Chinese collets all seem to be made by the same company and the difference in price is simply a difference in vendors. Without question the American, German and English ones are higher quality but it doesn’t seem to show up so much until one gets to the 0-1mm range.
For Sherline lathe users we do offer an adapter to use In both the head and tail stocks.
 

Jerry Kieffer

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May 31, 2005
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I understand that you generally get what you pay for in life but I'm wondering if that's really true with regard to ER collets. I have an inexpensive set of ER16 collets in metric sizes, several of which seems to clamp unevenly so I began shopping for a replacement set. There's a huge range of prices-from under $20 to over $400. I'll probably go with something in between but is there really a measurable difference in accuracy with a set costing, say $75 vs. a set costing $250? Country of origin (China vs. USA vs. Germany) has an impact, as does the source (general online retailer vs. industrial supplier) but the wide difference is still puzzling. Comments appreciated.
For what or how do you plan to use the ER collets.

They are designed to hold tooling arbors in machine tool ER spindles where even pressure is applied to a tooling arbor over the full length of the collet up inside of the spindle. This in turn allows the tooling cutting surfaces to be mounted as close to the spindle nose as possible achieving maximum stability and accuracy. Under these conditions, if your work involves machining to exact dimensions, then accuracy is critical. However if your work is non critical such as roughing work in a particular machine, then a lesser quality may suffice. The use of adaptors that extended out in front of a spindle are less stable and accurate thus often defeating the original designed purpose of the ER collet.

Jerry Kieffer
 

Hudson

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Jul 19, 2010
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I have ER16 Collets. I bought the holder and set of collets for a Taig Lathe that I have. Afterwards, I found that the collet holder could also be used on my Sherline Lathe and Mill.

My first set of collets were inexpensive and "not so good". I then bought a set of ten Techniks brand collets that are made to have 0.0002 runnout or less. They are quite nice .

My ER collets experiences have given me a lesson on how important the collet holder is. I machined the holders that I had to improve their runnout. I also discovered how important it is that the collet be tightened to higher torque values than you might think.

After upgrading the quality of the collets, and machining their holders, I have had good experience with them.
 

bartmes

NAWCC Member
May 20, 2012
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Thank you to all that responded. Hudson rightly pointed out, as I discovered after looking up torque specs for ER16 collets, you've got to use a lot of force to properly close the collet. I have no means of measuring the force so I'll be reverting to conventional holders in my Sherline mill.
 

Dr. Jon

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I went to ER 16 collets in my Sherline mill when I found that the regular holder had insufficient strength. In holding milling cutter I do not care much about run out. At worst it will make the cut a bit wider, but I do care about holding the tool securely.

I found that, when milling aluminum, the cutting force pulled to tool down into the work making my cuts run down into the work rather than producing flat parallel surface. My relatively cheap ER16 set up cured this.

I do not measure torque but I do use a pair of 10" open end wrenches to tighten the two bolts together after first making sure the collet is lined up and centered with bare hand tightening.
 

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