Are Your Retention Knobs Too Tight?

cat 40 spindle that's running shrink fit at 16 grand? Be honest, when that thing changes tools it bangs like a bitch.

Nope. Got another one that's been running 15K all day for 5 years. No pops or bangs.

Here's a video of a very similar machine. Notice, no pops.

No doubt HSK and Big Plus are better. But you have to weigh additional cost of HSK vs "good enough" with CAT.

Another possible solution is 40 taper Face Contact Big Plus Tooling. Big Kaiser is one brand. Video advertisement at site below:

They seem to have conveniently left out that you should have your spindle reground to take advantage of the Big Plus system if your machine didn't come with it. Plus you can still use your regular 40 taper tooling when max rigidity isn't needed.

Some independent information on various tool holding systems:

================================================================== Metal cutting theory and practice by David A. Stephenson, John S. Agapiou - 2006 - Technology & Engineering - 846 pages

Nope. Got another one that's been running 15K all day for 5 years. No pops or bangs.

Here's a video of a very similar machine. Notice, no pops.

Well, when it comes to cat40, hsk, etc...i'm all theory. But i will say this, on a hass at 12 grand the spindle belmouths. Maybe it's a cheap issue, I'm not sure.

But.... All you need to do is play the consistancy game. Everything repeats if the conditions repeat. What goes bad is when you make a proggy, and it roughs out the stuff at 1200 rpm, then goes into some drilling at a grand, then runs a tool at 12 grand for an hour doing some 3d. The conditions are too radical to repeat. A better approach is to rough out all the parts, then throw em in and do the 12 grand stuff last. last place I worked I got in an argument with the foreman, he demanded a finished part start to finish. I tried to explain when holding a tenth you have to pretend it's friggen hard and play by some rules. Being ignorant he would not understand. Bottom line was it was hard for him to predict how long things took. He couldnt give his boss an answer as to how far along the parts were. So because he was "unclever" I had to suffer.

Sound familier?