H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
- Jan 10, 2019
The PM935 mill comes with an R8 spindle. For several reasons I decided to go with ER32 collets, so for drilling holes, there's the choice of getting a chuck with a straight shank that mounts via a collet into the ER32 holder, or remove it and use a chuck that mounts directly into the R8 spindle. Which way do you recommend and why? I'm asking because I want to make sure I'm not overlooking an obvious reason for why it should be one and not the other. I imagine the answer will be "it depends", but I'd still like to know. The one reason I can imagine going with R8 is that it removes the play and inaccuracy in the ER32 setup, but at 0.0002 runout, that much error for drilling seems small. What say you?