Thanks fred, I've taken a copy of that.

Roger


ff wrote:
rlincolnh wrote:

Thanks Fred,

I had wondered if the length inside the spindle could be a problem,
which was why I made a point of mentioning the length. But I hadn't
heard any signs of distress as I spun it up through different speeds
on the way to 2000, so I didn't worry too much about it. I'll try all
this again with a shorter piece.

Is coolant per-se going to affect the chip/chipbreaker interaction
(maybe by cooling the chip?), or are you saying that using coolant may
help in achieving the appropriate DOC and feed rate to make the
chipbreaker work?

Roger



Here is a good article on chipbreaking from the Modern Machine Shop
trade magazine:

http://www.mmsonline.com/articles/049804.html

Here's an exerpt:

"The chip formation process implies that a fresh metal interface is
continually produced between the tool material and the workpiece at
varying cutting forces, angles and temperatures. When a cutting edge
performs its metal cutting function properly, it deforms some of the
workpiece material plastically and then pushes it off. Chips separate in
either of three ways: they break by themselves, they break against the
tool, or they break against the workpiece (see Figure 1, below)."


Fred