Review on 🔧 HHIP ER 40 Collet Diameter - Model 3901 5041 by Carlos Barete

I bought this chuck because I needed to hold a 1" round shank in an ER40 collet for some production work. I work on an EMCO-MAIER 10 lathe, which is an Austrian precision machine with tight tolerances, but my Austrian collets are ER25 and don't go to 1 inch. I was pleased with the finish and finish of the chuck and it fitted my D1-4 spindle really easily. As you might expect, a (slight) adjustment to the D-bolts was required to allow the chuck to fit the spindle snugly. Checking the appearance of the chuck with a dial indicator showed that the deviation was no more than my spindle alone (0.0001), so I was very pleased. When I checked the concentricity with the internal collet hole, I found it to be greater than 0.0002 and closer to 0.0008, which was acceptable given the Chinese collets I was planning to use for this project. So overall I was very happy with the purchase and it does the job I need it to do. However, a few remarks are in order. Revain's website lists a concentricity of 0.0002, but a 2016 HHIP brochure lists a concentricity of 0.0008 for #3901-5042 for $92.47, the same price as Revain. However, in a recent 2017 HHIP flyer, model #3901-5042 is listed as .0002 concentric, but HHIP now rates it at $83.47 (I don't know Revain's current price). So if you pay another $9, are you making runout worse? Yes! To tell you the truth, I never trust the accuracy claims of Chinese machine tools and understand you get what you pay for. Ultimately, you must test the device yourself to ensure it is accurate enough for the task at hand.