Fits well with the Dremel 3000, not to Proxxon etc.

UPDATE v. 25.12.2013
Meanwhile, I have all my Proxxon (2 IBS / E) and Dremel (3000, 2x4000 and 3x8200) with chuck upgraded because I had no more buck to look at each tool change for a suitable collet.
It is reported that the centering of Bohfutters not expected to reach the level of collets and 1 Amazoner has very bad measurement deviations, even at 1 / 100mm, measured accurately.

Well! I can not join me to and have no centering problems with any of the above-mentioned machines.
Also 1 preparator who worked fossils has no problems of this kind.
However, I am not Präzisionsfetichist who works on the 1 / 100mm and created parts for satellites or telescopes, but model operates.
For me, because nothing wobbles and the holes are round.

I can only guess that he caught a bad machine.
I have a total of 9 machines (also a Chinese, identical with Dremel 200) and they are all OK. If there would be a fundamental problem, I think he would be struck me several times at this number, but as I said, for me include more than 1 / 10mm and no 1 / 100mm.

Under these conditions I can only recommend replacing the collets against chuck.

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I bought the collets together with the chuck at Amazon for my Dremel 3000, because this is only supplied with 2 collets.
Delivery took place within 24 hours.
They fit perfectly, but both can be installed either on Proxxon yet another machine.
The chuck is ultimately much more practical, sufficient running around.