Chinese ER20 Collet Chucks, Anyone have them?

[Don B]

I may have just gotten lucky but I purchased 2 set (20 total) from the same seller and have uses and checked 14 of them, all are within the quoted tolerance, I was skeptical about quality so I ordered one set of ten first and after checking them I placed the second order, I'm very happy with them.)

I should have mentioned this in my original post, when I checked the runout on the ER20 holders I received I checked in 2 positions ( upper most extreme and lower ) on the internal taper where the collet sits, and any runout was parallel, one thing I did encounter was that the undercut that allows the holder to clear the R8 collet was not deep enough to allow the holders to seat properly against the spindle, I needed to grind approximately 1/16 off the face of the R8 collet, my starter set that the R8 collet came with was purchased from Novakon I'm not sure if people that have the R8 collet from the Tormach Tooling System have encountered this.)

 

[ronboult]

As DonB has mentioned the Tormach 3/4" R8 collet is shortened on the front face to allow the collet chucks to locate against the face of the spindle. All this is explained on the Tormach website. I bought my 3/4" R8 collet from LMS at a reasonable price.

I also bought some Tormach End Mill holders for End Mills with a weldon Shank. These I don't use much because they have more runout and many of my end mills don't have a Weldon Flat. More importantly they are not adjustable for height like the ER collet chucks which allows me to set most of my end mills at the same height ( very time consuming fiddly job) for easy rapid cutter changes during a machining job. My Mill is not CNC so cutter length offset is not available.

Ron