ER32 collet chuck

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Penultimate

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Aug 22, 2010
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Greetings
I ordered an 80mm ER32 collet chuck from eBay and ER32 collets from Amazon. I mounted the chuck on my lathe and measured runout on the chuck taper. The runout is negligible <0.001TIR. When I mount some of the collets I get as much as 0.01" runout at 2" from the collet nut. I actually got the 1/4" collet to have 0.002" TIR once. Every time I reload the collet the runout is unacceptable. I'm using a piece of drill bit stock (hardened and ground) as my measurement mandrel.

How can I tell if the collets or the nut is causing the runout?
Any other suggestions would be appreciated.
Thanks
 
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More4dan

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Mar 17, 2016
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Katy, TX
Are you sure the test bar is straight? I would try several of the collets too, maybe with drill bits to check. Check the collets for any burrs that could be creating the problem.

If all the collets are given excessive run out, I'd be worried about the nut. If it's mixed, I'd be concerned with the collet set.

I've not checked runout on mine but they seem better that my 3 jaw chuck. I'll have to breakout the test indicator and check this weekend. I bought my chuck and collets through Banggood.

Danny



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its_virgil

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Jan 1, 2004
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Wichita Falls, TX, USA.
Are you seating the collet into the nut then into the chuck? A common mistake is to insert the collet into the chuck then screwing the nut onto the chuck. When the nut is removed from the chuck the collet should be ejected from the chuck. Incorrect use is a common mistake.
Do a good turn daily!
Don
 

Penultimate

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Hi Danny
I'm pretty sure the test bar is straight but I will check it to be sure. I have a couple different drill blanks. The all gave various levels of run out. I ordered a new nut and a new 1/4 collet from Shars. I'm going to try them to determine which part is bad. I've not had problems with my ER25 set.
Thanks


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Penultimate

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Aug 22, 2010
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Bartlett, IL 60103
I picked up a 1/4" collet and a collet nut from Shars Tool, conveniently a couple miles from my house. Those two parts proved that the collet set is bad. I bought them from Amazon so I can return them. I ordered a set from Tpactools in Schaumburg IL.
It think it is interesting that there are three tool companies located in the Chicago 'burbs that have reasonable prices on tooling, CDCO, Tpactools and Shars.
 
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