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this is a total noob question, and I'm aware of that

having spent the past 20+ years conventionally machining and only with a brief excursion into CNC machining on a very limited and dated CNC mill years ago, I'm slightly at a loss here and hope to gain some help:


Tool-Offsets:

I understand the concept... but I think I'm doing it wrong:

here's my approach:
So far I've been doing the tool setup like this:

1. HOME the Z-Axis (at least the Z) (my machine has inductive reference switches, so homing is pretty precise)
2. Insert a tool, as a first tool I've set up the Probe, and given it Tool No. 96... (UCCNC max. tool number is 96)
3. Probe down until it meets the tool setters reference surface...
4. Put the Difference (for example -240.330mm) as a tool offset into the controllers (UCCNC) tool-table for tool #96.)

Repeat 2-4 for each other tool.... numbering them 1 to XX

then when I want to mill a part that I've designed in Fusion 360
I do this:
1 Load Tool #96 (the Probe)...
2. G43H66 to load the Tool Offset for the Probe
3. Probe the work piece and use it to set the G54 work coordinates to X/YZ to ZERO.
4. run the G-Code ...

it does work, in as much as I've been able to mill parts like that.


however when I searched the topic online I came across this video:
https://www.youtube.com/watch?v=wDGvQHevN9Y
the machinist in the video explains to USE the SPINDLE-NOSE to set the base-zero before measuring the tool offsets...
So he homes the machine
then drives the spindle down to make the tool-setter say "Zero" and sets this a Z-ZERO...
then proceeds to insert each tool into the spindle and use the measured offset from that ZERO.
This of course will get you the offset in reference to actual stickout difference from the Spindle nose...

but when I do this method... then say load my 3d Probe (manual), tool 96, do a G43H96 to get the offset... then G54 Zero on my part...
then load a different tool... and put that to "zero" it goes too far - the offset is not correct..
Also I think with this method, every time I would want to measure a new tool, I would again need to Zero on the Spindle nose first...
OR what am I missing???


is my method with relying on the homing reference position bad?

help please?, pretty please?
thanks!

the machinist in the video explains to USE the SPINDLE-NOSE to set the base-zero before measuring the tool offsets...
So he homes the machine
then drives the spindle down to make the tool-setter say "Zero" and sets this a Z-ZERO...
then proceeds to insert each tool into the spindle and use the measured offset from that ZERO.
This of course will get you the offset in reference to actual stickout difference from the Spindle nose...

When you use this method, you need to set G54 Z zero with the spindle nose, as that's what all your tools are offset from.

ger21 wrote:

the machinist in the video explains to USE the SPINDLE-NOSE to set the base-zero before measuring the tool offsets...
So he homes the machine
then drives the spindle down to make the tool-setter say "Zero" and sets this a Z-ZERO...
then proceeds to insert each tool into the spindle and use the measured offset from that ZERO.
This of course will get you the offset in reference to actual stickout difference from the Spindle nose...

When you use this method, you need to set G54 Z zero with the spindle nose, as that's what all your tools are offset from.

thanks... I got it... I stick to my method then... seems better (using the Home-Ref on Z)

There are various methods of accomplishing the TLO, I have been basically using the method you described in your first post for 20+ years and it's perfectly reliable. If you always use the same touch off (probe plate, gauge blocks, etc.) for every tool at all times, this allows you to use any tool you want to touch off the workpiece, even if the height changes for a new job. Just use G43H[chosen tool] prior to touching off and every tool that has been comped is instantly comped to the new workpiece height. Some people prefer to use the current workpiece to set their tool lengths, but doing it that way means you have to do it all over again for a new workpiece height.

dhanger wrote:There are various methods of accomplishing the TLO, I have been basically using the method you described in your first post for 20+ years and it's perfectly reliable. If you always use the same touch off (probe plate, gauge blocks, etc.) for every tool at all times, this allows you to use any tool you want to touch off the workpiece, even if the height changes for a new job. Just use G43H[chosen tool] prior to touching off and every tool that has been comped is instantly comped to the new workpiece height. Some people prefer to use the current workpiece to set their tool lengths, but doing it that way means you have to do it all over again for a new workpiece height.

Thanks!
appreciate the feedback on this..