OK. While I wait for bearings to arrive to fit inside the TPU printed tension rollers I thought I'd take another stab at slowing down
@David
He's going way too fast on his CNC conversion but I think I've figured out a way to muck with his head.
Recall he's had a CNC router for a number of years pretending to use it and cut things........
Well. LinuxCNC when we look at the machine co-ordinates after homing looks like this:
And it does make sense right. For a CNC router we've gone up first out of the way of everything and then moved X and Y over to the home switches. Now a move of the cutter to the right increases X and a move away from us increase Y both in a positive direction.
Makes perfect sense for a router. Even so for a CNC mill where the head moves upwards to the home switch out of the way of everything.
The problem is we don't really know the distance from the TTS tooling reference surface (bottom of the quill) to the table.
Why do we need to know this?
Simple. Everything is placed onto the table in one form or another. And when you have a tool setter it's nice to be able to measure the length of a tool and put it into the tool table. (And know what is happening).
So here's an example:
With the Head all the way up or the table all the way down (Knee mill) we need to be able to measure this distance because it changes as soon as we tweak the home switch position.
And a side effect of this is as we move closer to the table the distance changes from 0.000 to a negative number so for the rest of this discussion we'll mostly talk about absolute values.
This is where I get to muck with head of
@David. Much easier to think of he Z value being 12.718 and as we move closer to the table that value gets smaller.... For that matter how do we measure the actual height when our tool setter trips under pressure from the tool?
How do we know that since we don't know the distance to the table? Especially if the quill registration won't even reach the table
This requires one or two 1-2-3 blocks..
After a Home Operation our Machine Co-ordinate Z=0.0000. If we move the head down until we can just barely shove a 1-2-3 block under (say the 3" distance) we can record that number. In my example above that would be Z=-9.7180". In other words we've just moved the Z axis 9.7180" in the direction of the table (or the knee upwards) but it's a negative direction. Add the -3.00 size of the 1-2-3 block to that and now we know the quill TTS reference surface is 12.718" from the table after a home position.
Why is that important. Say we now move the head down (or the knee up) and have the reference surface of the quill touch the tool setter. When it trips we stop. Again we'll see some sort of strange negative number that doesn't make any sense.
Oh but wait! The Z axis reads -9.055" when we trip the tool setter. If we take the absolute value of that and subtract that from the overall height of 12.718 we discover the tool setter height when tripped is 3.663".
That's important and we need that value when we use the tool setter to determine how long a TTS held too is. More on that after
@David recovers from the confusing information.
