Re: [CAD_CAM_EDM_DRO] They're called fixture offsets was Re: 1 more "Hip Hip" for Lim "StepOffs"

ballendo wrote:

>Chris,
>
>This is what fixture offsets are for...
>
>

Well, in your theme they HAVE to be, cause you don't have a limit step
off option available !! :-)

>A fixture offset is nothing more than a set distance from the
>physical location of the home switches. Most current machines have at
>least 6 (G54-59), and many have MANY more.
>

FlashCut has these six "Fixture Offsets" and that is exactly what I use
them for "Fixtures", and only Fixtures. These are physical
device/clamps/mechanisms I can locate on my table top via Dowel Pin
Locations. Seeing as I only had 6, I sure would hate to waste some of
them on "head offsets" though. That is what the Lim Step offs have
accomplished for me, as well as making any hardware limit switch
adjustments obsolete, as now I can place any spindle on the machine and
adjust it out via controller software, no commands in any code, no MDI
thingys to remember after homing sequences.

By your definition above, Flaschuts Limit Step off adjustment IS indeed
nothing more than a fixture offset...They certainly could have called it
"head Offset"... . Its just not tied to any code and it shouldn't be.
For that, wonderful. I can "tie offsets" to >hardware< ! I love it.

It just tons easier ! Put a head on, open the "setup" for that head,
home the machine. DONE, ready, aligned to fixed fence, aligned perfectly
for use of Any of the available 6 fixture offsets. Also ready to Run ANY
existing toolpath I have created over the last few years no matter what
spindle or head....And, I didn't even have to look or remember which
G-offset I was supposed to use for which head. The FC "setup name"
defines the head ! With 256 character file names,,, I sure can describe
a lot of head/ramp/speed/yaddayaddayadda preset issues ! Think about the
options to accomodate different rates because of spindle weight, maximum
speeds, etc.... Your G5x can't do that ! My setup file WITH a step off can.

I have 4 different "heads" I can use, and unfortunately, they do not all
carry the same centerlines. Now I could build some very special holders
to get them all perfectly lined up, but, well, I don't have too !

Thus, If I wasted 4 of my "fixture offsets" for "head offsets", I'd be
in trouble with all of the G5x commands in my existing and routinely run
programs for the 5 fixture locations I already have ! 5+4=6?

>(snip)And these WILL be away from the home switches (by
>whatever amount was determined at setup(for toolpath), or
>configuration(of the control)).
>

See now we are getting somewhere..... First off, FC has not allowed you
to say "go to fixture offset x" (it will soon though). So at the
control, you could NOT get there without running code, or typing in the
locations and do a move command. But all of that is Moot. Even if I did
enter it at the control to adjust for a head offset, I waste an offset,
go thru more steps to do the same thing, Not to mention, I'd by far
rather leave a G5x command to the execution of code, and not a manual
entry thing just so you can set part 0.

> Which of these two words fit best is
>largely determined by the control topology, and really simply means
>how easily the offsets are accessed, determined and changed.
>
>So to sum up, any "responsible" control will have ONE, and one only:
>machine HOME. It WILL be at the switches themselves.
>

We'll be on two different sides of the street on this one. I feel a
"responsible control" will give its purchaser MORE than they really need
! It comes down to "control".... >Control< What ?? Seeing as how a limit
offset could be added with virtually no sweat produced by a competent
programmer, Why not add it ? Then the Doors of opportunity open wide for
the developer for his control to go above and beyond the needs of some
simple 3 or 4 axis rotary machine and into the world of controlling just
about anything that moves. I've mentioned it before.... You'll pry it
from my ccccccold dead hands !

>AND this control WILL have the ability to "refer to" other positions
>as toolpath or part zero for use with toolpaths. These are the
>fixture offsets. So ALL of the things you mention ARE handled by the
>fixture offsets, and it simply becomes a case of terminology
>complicating things. Something for which CNC is well known!
>

That is the case in point.. all one needs is what one "needs". I am here
to tell you, 6 Fixture offsets are not enough for me as I have more
heads and more offsets than 6. Thankfully, Flashcut Version 2 has added
"reference points" that serve the same function... 29 of them in fact,
for those who refuse to use the Limit step off features. All callable
from the G-code file.

Nonetheless, I'll not give up the Limit step off. Never ! It allows me
to adjust machine zero in mere split seconds, without using an otherwise
G-code commanded location, or getting out the wrenches and trying to
make or take .001 out of a mechanical switch.

Chris L