Re: [CAD_CAM_EDM_DRO] Re: Tool change also smart/dumb boxes

ballendo@... wrote:

> Hi.
>
> I just read Rays' excellent post and Smokes' response, and all the
> sudden I realised (when Ray pointed out EMC tool change support
> capabilities):
>
> There is NO provision for 'telling' a toolchanger mechanism 'which'
> tool we want in almost every CNC S/W pkg. mentioned on this list!
>
> Many have a "toolchange' command (M06) and some have a "toolchange"
> location, but where is the info for WHICH tool to change?! They
> nearly ALL assume manual change!

No, not really. I think GM Powertrain had a VMC set up with an ATC
on the original EMC about 5 years ago. Much of the code is still there.
I'm going totally from foggy memory, but I think an M06 T4 will switch
to tool 4. What you would normally do is have the tool number sent
to some digital I/O output bits to tell the toolchanger which pocket to
fetch from. Then you need one extra output bit to start a tool change,
and one input bit to advise the EMC that it can continue.

> Most also support a list of tools 'mapped' to tool numbers with the
> gcode "T" word. But there is no ACCESS to which T number is active,
> or sought, that could be used by a toolchange mechanism to select the
> desired tool.

There is code deep in there, somewhere. There is, in fact, a library
of assorted auxilliary routines, like automated lube pump control,
tool changer, spindle speed control, etc.

>
> This would certainly be desirable in a smart black box, and a useful
> provision (I/O bit count) in a dumb box!
>
> 3 bits selects 7 tools, 4 bits = 15 tools, etc. (assumes 0 is no tool)
>
> If the tool changer is 'somewhat' smart, then it could use a serial
> command set and protocol, using only one bit.
>
> Possible feature-itis? Yes. I'm just surprised I haven't run into
> this before. Most of my experience is multiple heads and 'go to a
> certain position/slot' tool changes.
>
> Hope this helps.
>
> Ballendo
>
> P.S. Thinking out loud: I suppose this is another case where the
> machine (at the expense of time) could move and press an index button
> X number of times to bring the tool(carousel) into position. Lot of
> extra toolpath, and possibility of crash if the 'index' doesn't :-(,
> but it does get around the problem...

Yuck! This sort of stuff is a way to get around closed machine controls
where you can't add any features without paying tens of thousands of $.
EMC IS open, and we can add all this stuff. If the code isn't quite ready
to just put in your I/O addresses and assign the bits, it is probably pretty
close.

Jon