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Author Topic: Z Axis Machine Coordinates Not Changing  (Read 881 times)

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Re: Z Axis Machine Coordinates Not Changing
« Reply #10 on: June 23, 2018, 10:28:49 PM »
Hi tbj1,
that explanation makes sense, you were looking at the wrong DRO. That does raise the question why the DRO number has been changed for the Plasma screen.

As you may know Mach4 allows for THC control it is in fact enacted by the motion controller rather than Mach. At this time there is only one external motion controller
manufacturer who has devoted the effort to enact THC and provide a custom screen  for its Mach4 controller. Because of the rapidity at which Mach4 software cycles
there may be the opportunity to do THC by scripting within Mach4 with minimal controller support required ie a software solution rather than a realtime hardware solution.

http://www.machsupport.com/forum/index.php/topic,37405.msg255859.html#msg255859

The essential idea is that the Z axis remains just that but in addition you piggyback an out-of-band axis on top of the Z axis to wiggle up and down for THC purposes and not
therefore break the axis coordination that manipulating the Z axis directly would imply. It would of course be possible to wiggle the Z axis as if it were an out-of-band axis but the Z axis
DRO would not follow the THC variations. The actual  (total) position of the Z axis would then be the sum of the Z axis DRO proper and the THC variation, possibly in a second DRO.

My suggestion is that the #86 DRO in the Plasma screen is analogous to the second DRO tracking THC variations as proposed for Mach4.

Craig
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     and I miss him!

Offline ger21

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Re: Z Axis Machine Coordinates Not Changing
« Reply #11 on: June 23, 2018, 10:52:03 PM »
http://www.machsupport.com/Mach3Wiki/index.php?title=OEM_DROs

86 is the  A axis Machine Coordinate DRO.
Gerry

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