Re: [CAD_CAM_EDM_DRO] Questions about chipbreaking inserts.

Hi,

This is really a machining problem and as such has no place on this list. I
have been machining stainless steel for a few weeks with the same problems
if you want to email me offlist.

Regards,

Terry

> We are running chip breaking inserts on our CNC retrofit lathe. (13x40,
> 2 HP)
>
> We've got a little problem with swarf buildup, actually a big problem.
> When we machine a part of considerable size, removing a significant
> amount of material, the swarf will build up around the chuck, choke the
> coolant flow to the tool, etc. We often can't run a complete program in
> one go without having to periodically stop and clean things out. This
> becomes a big pain.
>
> Details: we are running TCMT321 (7 degree rake) inserts. This weekend
> we were machining 3" diameter 4140 steel parts. Total volume of
> material removed was about 6 inches^3. We were turning at 750 RPM,
> feeding a nominal F6 on a 20 thou cut. By nominal, I mean that someone
> might have been running a 50 to 300% feedrate override. Our tool height
> is set almost exactly at center height.
>
> The "chips" we were getting off are really 6" to 18" long swarf
> stringers. We have machined steel and gotten actual chips off, but I
> can't remember exactly when or under what conditions.
>
> Questions:
>
> a) what sort of chip breaking performance should we be seeing ?
>
> b) would the lack of chip breaking performance have anything to do with
> running a relatively small insert (ie 321) for the depth of cut ?
>
> c) how does one prevent a massive buildup of swarf in and around the
> chuck and tooling ?
>
> Thanks in advance,
>
> Kim