[sooncheng]

I used cheap ER32 collet with BT40 holder, TIR was around .05mm haha will using smaller collet and holder gives better runout (like ER16 collet, I prefer collet system because I have to change my tools quite often)

I think I had around 12mm stick out which was the minimum I can get before clamping on the coated surface of the tool (can I actually clamp on the coated part of the tool?)

Cheng

[joeavaerage]

Hi,

Circumference = 2(Pi)r, not 2(Pi)

circumference = 2 x PI x r r=radius
circumference = PI x d d=diameter

tool diameter =1mm therefore circumference = 1.0 X PI=3.141mm

Craig

[hpappsguy]

Hi,


circumference = 2 x PI x r r=radius
circumference = PI x d d=diameter

tool diameter =1mm therefore circumference = 1.0 X PI=3.141mm

Craig

Craig, you are correct. Both formulas are the same. My apologies.

[hpappsguy]

I used cheap ER32 collet with BT40 holder, TIR was around .05mm haha will using smaller collet and holder gives better runout (like ER16 collet, I prefer collet system because I have to change my tools quite often)

I think I had around 12mm stick out which was the minimum I can get before clamping on the coated surface of the tool (can I actually clamp on the coated part of the tool?)

Cheng

you can clamp on the coated surface, but it is not best practice as it hurts your TIR. In your case, choosing one over the other, I'd go for rigidity. 12mm stick-out is 12 x Diameter. A rigid projection is 3 x Diameter. A stable projection is 4 x Diameter.

We use only Swiss made Rego-Fix ER collets (they invented the product). There are other excellent options such as BIG Kaiser (Japanese), and Deibold (German). You get that you pay for in tool holders. There are others, but you always need to understand where their stated runout is measured at (collet nose, 2.5xD, 4xD?). Generally, if you can get 0.0002 -0.0004" in an ER, then you are doing fine. The ER collet business isn't real straightforward and there isn't a standardized reference for advertising runout. Although, I think 4xDiamter is the most practical because that is closest to the projection of a tools cutting tip in a real cut.