Re: CNC - Positive Quadrant

["Bob La Londe" <none@xxxxxxxxxx>]

Bob La Londe" <none@xxxxxxxxxx> wrote in message
news:KbUQt.185644$Ct1.149293@xxxxxxxxxxx
> "NickMark" <nmarkowitz@xxxxxxxxx> wrote in message
> news:df093553-4fd5-4180-92e8-1becec010d87@xxxxxxxxxxxxxxxxxxx
>> On Monday, August 19, 2013 2:01:04 PM UTC-4, Bob La Londe wrote:
>>> I have noticed that quite a lot of people position parts in CAM in the
>>>
>>> positive quadrant of the Cartesian plane.  It makes a lot of calculation
>>> and
>>>
>>> planning easy so it makes sense.
>>>
>>>
>>>
>>> When you place a vise square on the table the moving jaw to accommodate
>>>
>>> different size stock is in the negative direction usually.  This
>>> requires
>>>
>>> touching off and relocating ZERO for Y a requirement for every single
>>> job or
>>>
>>> part of a job after rotating a part.  Even those that don't require a
>>> huge
>>>
>>> amount of precision.
>>>
>>>
>>>
>>> The obvious solution is to design a vise with the screw drive on the
>>> other
>>>
>>> end positioning the moveable jaw in the positive direction.
>>>
>>>
>>>
>>> The less obvious but much easier solution, is to work in the X+ Y-
>>> quadrant
>>>
>>> or move your work to X+ Y- quadrant after you have done all your
>>>
>>> calculations, layout, and planning.
>>>
>>>
>>>
>>> (FYI:  I tend to work with XY ZERO in the center of my stock because I
>>> do a
>>>
>>> lot of rotations around an axis and/or symmetrical work, then I move my
>>> work
>>>
>>> to the positive quadrant so I can just touch off rather than touch off
>>> and
>>>
>>> calculate.)
>>>
>>>
>>>
>>> I was trying to develop some work processes that allow me to do certain
>>>
>>> types of jobs and setups faster, but then after typing all this it
>>> occurred
>>>
>>> to me that for most of you guys its probably all mind numbingly obvious.
>>>
>>> LOL.
>>
>> I have several machine shops i do repairs for and its amazing to watch
>> those machines work and do there thing. One of these days when i have
>> time and shop owner has time wants to show me how to program one
>
> Its easy.  Just turn off the limits and program:
>
> M3 S40000
> G00 X-5000 Y-5000 Z-2000
> G00 G00 X5000 Y5000
> G00 Z 1
> M5
> M30
>
> Even on a machine big enough to handle that it will give the owner
> conniptions.  LOL

P.S.  On my big (big for me) mill it would just tell me the program exceeds
soft limits and refuse to start.  Of course that's because I set it up that
way.