CNBTR 16mm CNC Spindle Motor ER20 A Type Extension Rod Collect Chucks Holder and 13pcs Spring Collet CNC Milling Lathe Tool Set for Workholding

Many other reviewers and even Ave have noted that these are incorrectly machined with an off-center step cut into the collet. That is not an error, its a feature. When you use it, insert the spring collet at an angle such that it slides under the off-center step from side. Then straighten it. That off-center step everyone mentions is there to hold the spring collet in place. Try it.Insert spring into nut. Insert tool into spring. Screw the whole thing into the arbor.Machining is good and the parts are all good quality. The assortment is good up to 13mm and I've tried it with bits down to 1/8" and up to 1/2".If you realize the right way to use the spring and cap, you'll like them. I would buy them again.

The collet nut isn't machined correctly. The snap collar for the collet insert is off center by about 1/8 of an inch thus the inserts are not centered, nor will they actually fit into the collet nut. There was obviously no quality control.

Overall, this product is ok. Within the nut, the machining is not an error like the other reviewer said, but is instead supposed to be eccentric for ER style collet systems.However, the bore on my unit is about 0.09mm out of line with the collet taper, which isn't great. It's nice and concentric with the body, but the taper is on a different axis.

utilisé sur un tour a métaux .le produit .... CNBTR ER20 A Type Extension Rod Collect Chucks Holder CNC Spindle Motor and 13pcs Spring Collet CNC Milling Lathe Tool.... est de tres mauvaise qualité a tout les niveaux inutilisable !!!!!

El producto me llego antes de la fecha prevista aunque eran Navidades. De momento no he podido usarlo pero tiene muy buena pinta.

Perfect, like expected, fast shipping