If you want to use the knee for tool length compensation the tool length would simply need to be passed to the knee axis to move it up or down by that amount BEFORE a tool is actually changed so you have room for it at your normal tool change Z height. Then the program sees all tools as the same length.

You'd probably want to compare the two offsets, and only move if the new tool is longer, as you don't really want the knee cranking up for some short tool after running some long tool, before you've changed the tool.

Slowly making sense, thanks

So in the code all tool length compensation would be turned off and I would likely be editing the M6 Start ??

That's actually a good question.
You still need to use tool length compensation, and use the tool lengths in the tool table to move the knee, but how does Mach handle that?
Not using compensation would work, if you know the knee will move to Z in the right position.
Other option is can mach combine the position of the knee, with the quill?

I think the question of Mach combining both knee and quill was asked before and IIRC it can't.

One possible idea was to drop the knee in the M6start, do the change then lift the knee in M6end to its original position minus the new length, something like that anyway.

However i seem to recall bad issues with the CSMIO if there is any code at all in M6end, i should have made notes back then, i think it faulted out if there was any axis move while in the tool change routine if there was code in M6end.

On the mill its set for "Manual tool change" Does the "manual" bit i.e. the pause, come at the end of M6start and when you press return it runs M6end??

Try this and see if it does what you want.

http://www.machsupport.com/forum/index.php/topic,13630.msg89523/topicseen.html#msg89523


Mike

Hi

thanks, that is the same guy that was helping on another forum

It his code i have pasted into my M6start


I started a new thread to keep things clearer :-

http://www.machsupport.com/forum/index.php/topic,36265.0.html

Made a little progress today, got the motor mounted...



Hopefully get the limit switches mounted tomorrow

Looking good.

What ratio are you looking to use? Is that an HTD belt?

Mike

Yes HTD 5 x 15mm

IIRC it was 22/72 ratio - 3.2727:1

Got the limits and home switch fitted today, moving switches and fixed cams so I could do it all with two switches

Top is limit, bottom is home...



Had to alter my plan of homing to top as with the vise fitted the bed will crash...



All the way down, a lot of cranking....



Wired the limit switch into the loop, just the home to take back to cabinet...

I'd forgotten how busy it was in the cabinet



The knee axis servo drive will have go on the right-side wall i think.

Hopefully get the drive temporarily fitted tomorrow and powered up the day after.

Ok, got it wired and powered up.

Little snag to start with, i'm a bit rusty here....

When you take Mach out of reset, the servo starts creeping without command, anyone give a pointer as to where i start digging??

It does not creep for long as you get an ePid fault.

Thanks