Curiosity question on "pre-emptive" tool changing.

[beefy]

Nothing but a curiosity question here. I’m only into plasma at present but in my new job I’m learning/operating a DMG machining centre with Heidenhain control.

I noticed the way it has “pre-emptive” action with the tool changing. You get a tool call and the tool changes out. Immediately after that code line/block, the next tool number is given. So I’m guessing that moves the next tool into position while the just changed out tool is machining away.

Would I be correct in saying this is how you’d do it in UCCNC.
I realise there’d have to be communication between UCCNC and the toolchanger:

M6 T4 (Beginning of code - load tool 4 into spindle)

T7 (A macroloop / plugin monitors this using Getcurrenttool(); and informs the) (toolchanger to bring tool 7 into the “ready to load” position)

Various gcode…………..

M6 (Change out tool to #7 – their could be conditional code in the M6 macro to test that) (tool 7 had arrived in the “ready to load” position)

T3 (As in T7 above, tool 3 is brought to the “ready to load” position while tool 7 is in use)

Various gcode…………….

M6 (Change out tool to #3)

[beefy]

Cheers Terry,

yes it's a dual holding tool changer arm, with a central pivot point and each end holding tools. The arm basically does a 180 turn "swapping" the old tool for the new one.

And of course the old tool ends up in the pocket of the magazine where the new tool just came from. Therefore I'm guessing the tool changer software is continually keeping track of what tool is in which magazine pocket, AND it must save this data upon shutdown so that when the machine starts up again, it knows exactly what tool is in which magazine pocket.

If I ever make a tool changer, I want to make one of these

Keith.

[Battwell]

its quite easy if like vectric it posts out all tools at the start of the posted file (tools used in file)
programming it is quite easy from that. - tracking /saving was more fun to do as i found out then i wrote my tool change routine.
constant swapping to double, string etc and back to write to screen and to profile- in case of a crash etc- so tool positions and numbers in rack would be remembered.
i have all that code done now- took me about a week to write it... and it looks dead simple on screen so you wouldnt see the work in it!
i think tracking/saving everything is the most important part that could get overlooked- and get you in trouble.
it was written so i could put any tool in my rack (over 100 tools used here) - anything over 96 gets loaded manually
https://www.youtube.com/watch?v=PGzKizWuafo see- looks simple

and then- tool pockets get added to the latest development version tool table... lol thanks balacz

[ger21]

Then when switched to ATC UCCNC would only look at the slot#s at teh M6 call.

I would want this to be optional. Maybe people don't want to select tools by the slot #?

[ger21]

Maybe some people with ATC's don't want to use Slot numbers. Or, people that use my screenset that don't even have ATC's, but have UCCNC set to "use ATC".

[ger21]

Why would you check ATC if you did not have one ?? RTFM?

Because that's the only way to get UCCNC (the M6 macro) to automatically zero your tools during a tool change, without actually stopping and restarting the g-code.

[ger21]

Those of us without ATC's still use the ATC macro.
Not everyone works the same way that you do. For some of us, it's fine the way it is. That's why it should be optional.

[Battwell]

I've done it the way I prefer- that also uses a normal posted m6 call
My m6 just calls tool number i.e. M6t67
The m6 macro I wrote keeps track of slot numbers the tool is stored in and collects from the correctly populated pocket.
Added to the end of the m6 code- an option to probe tool length and store in tool table or not if already probed. ( I allow it to probe on first run of the program- no need after as I have fixed length collet chucks.)

Before I added the atc spindle I'd just use m6 to probe and set/ verify length

Lots of things people may want to do.

[Battwell]

Re hot swap atc... I believe it's better to run the tool changer via a separate plc
Then it just requires a change ,data and done signal
Let the plc do its job while the machine is running