Keeping tool length offset when changing tools

iusedtoberich · May 20, 2019

I'm on a Taig CNC mill with an ER16 spindle. What is a good way to cut a part that uses multiple tools with a simple machine such as this? (The mechanical part of it, not the tool length offsets in the controller software).

-Are you touching off on a reference height every tool change (mid part)?
-Is there a way to set all the tools before beginning to cut? I see some end mills come with a plastic collar attached to them that looks like it butts up against the face of the collet. Is this good enough (plus/minus 2 or 3 thousandth's) in repeatability?
-I went looking for those plastic collars to add to my existing end mills and did not find anything. I only found them pre-attached, but not in the end mill style I wanted.
-I recall for larger machines, when I was working a short while in a machine shop years ago, there were toolholders that clamped the end mill with a set screw against a flat machined on the side of the end mill. I did not find anything like that for the ER16 size, but maybe I looked in the wrong place. Maybe the shank diameter for tools common to ER16 is too small for this clamping scenario.

Thanks for any advice.

whammo57 · May 20, 2019

someone posted a little angle made of delrin that they used for setting a new tool to the proper length.................

Kim

conetip · May 20, 2019

There is a height reference thing in Mach 3 that someone wrote for it. So for multi tools, it tool changes, goes to near the reference piece is, then comes along and touches off this after the 1st tool has been touched off the work piece. It has a piece of circuit board and is linked somewhere in the control. After the initial wok height setting, it goes to the reference tool, and every tool after it goes to the reference tool. It is within the limits of the machine. But is easily better than 1 thou for the tool heights over 5 tools. It works well. It is incorporated into my Mach 3 on my router.
The only other way of setting tools, is to make a dummy spindle, mount the tools into a custom made holder, so in my case is ER20. Then use I use ER11 collets to hold the tools and set the tool height with a grub screw in the bottom of the ER11-Er20 collet adapters. I have the tools set at the same height within 0.01mm when clamped into the dummy reference spindle.

GBCues · May 21, 2019

I use Centroid on my machine. We have the option to replace the standard M6 tool change with a customized macro that pauses the program, prompts me to install tool x, then asks me if I want to reset the reference point or continue. If I choose reset, it then does a tool touch off subroutine. At the end of that subroutine, it prompts me to unclip the tool touch off, restart the spindle and press Go to continue.
Different custom macros allow for multiple tool touch offs for multiple WCS's if needed.
You don't say what program you're running, but I'll bet something similar has been developed for it.

Keeping tool length offset when changing tools

iusedtoberich

AzB Silver Member

whammo57

Kim Walker

conetip

AzB Silver Member

GBCues

Damn, still .002 TIR!