>None of the Mori Seiki, Kitamura, or Hwacheon machines I have used have this 
>magic ability. ( I leave out
>Mazak>- cause they are just different, and Okuma, which doesn't really break 
>the rules, they just made up
>there own.)

Greg - you can safely add Mazak to that list too - My very current Matrix Nexus 
control in its Mazatrol conversational mode, true, can do modal-safe restarts 
(because each machining op/pocket/line/arc isn't a block of gcode or sub; it's 
a description of the operation in a standalone, complete manner), you don't 
have that luxury in EIA/traditional GCode mode! True, yes, there are 4 levels 
of TPS (no, not "reports", but manual teach points that can be used to move out 
of the work, then return back in) - however, if you stop the spindle, you get a 
spindle abnormal alarm. Reset, dump program. If you move out of memory or tape 
mode, dump program. If you attempt to open the door, door interlock alarm, 
reset, dump program. Move to MDI? Dump program.

There is also a restart function. It turns out to be non-modal. You need to 
have searchable strings/comments/ sub numbers on your code for that to work, as 
the Matrix doesn't use line numbers. Again, all aimed more to the 
conversational/Mazatrol or manual machining modes than streaming GCode. BTW - I 
don't use Mazatrol conversational. At all. I build my CAM with VisualMill, and 
it is a happy production scenario. I also use VMill to write code for my hobby 
EMC installs. (Other customers use anything from hand to Master X and Gibbs.)

However, in a weird twist of fate, I think it ends up being more the way you do 
have to evaluate your methods to the machine, than trying to force the machine 
to use your methods - for instance, true, it would be fabulous to, upon 
discovering a broken tool (on a machine with no tool check or management) pause 
the program, have the tool disengage, spindle stop, change tool, update 
offsets, then re-engage and continue - however - that's a lot of non-program 
interference, and is an incomplete solution - it's also likely that the broken 
tool left a scallop or poor edge on the cut, and you don't have the opportunity 
to BACK UP - you only have the opportunity to carry on - in that case, you've 
likely made or are about to make your workpiece unusable. Also, it's important 
to consider, why did the tool break? Is there debris/interference/tool remnants 
left that will cause more failures? I embarrassingly admit, I do mess up on a 
feed/speed/DOC entry more than occasionally, just trying to get the first run 
in. And the tool goes pop. I don't want to rerun that mistake, I need to go 
back to my CAM and fix it, then run it correctly from the start. Thus, for the 
most part, I'll break down my machining ops into a lot of little sections that 
I can (and do) post, then run, individually - it's not uncommon to have 10 
little programs that I load and run sequentially for the first-off run. If I'm 
happy with the optimization (which I rarely am the first time), I'll then go 
back, fix, and post everything as a single program.

Since I'm a specialty resource, not a job shop, I don't have to justify my 
spindle-on time; in fact, I probably only have about 600 spindle hours in the 
past year on that particular VMC, which would barely break in a new machine. 
That also means I don't have to justify a 5S, lean, super-optimized, kanban, 
every-second-accounted-for machining principle. I probably produce 10 or fewer 
parts in a single run, with  20-50 of the same family - EVER. That definitely 
fits the "low-volume, high-mix" profile. So, given that, I don't feel bad about 
having to do things twice in regards to a CAM session. I also never make "just 
one". If I were a lights-out job shop owner, I would want and demand tool 
management (that I do have on my Matrix, I just don't use it either) - but I'd 
also have a lot of other automation working in concert for workpiece movement, 
measurement and verification - and with any luck, the incoming dollars to 
support it. For that case there would also be no need for manual interruption 
of a program; a workpiece would likely still be damaged, possibly continue to 
damage other tools, but most likely just carry on with the occasional failed 
part that gets tossed into the scrap bin. When doing a night run of 500 parts, 
overrun with 10%, tossing one or two isn't a big deal. But again, it's not 
something I specialize in.

This isn't a photocopier-scenario where interrupting a job to copy one page of 
someone else's document is okay - every time I see a point where I'd think 
"hey, I wish I could interrupt and do...x..", it's quickly followed by "but it 
really wouldn't make any difference, since ..y... is screwed up anyway".

Just a few cents worth,

Ted.




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