G00 Z2.00 - why?

This is the first part of a gcode for a mill job:
G90
M03 S24000
G00 X0.0000 Y0.0000 Z0.0000
G00 Z2.0000

Why does estlcam insert that g00 z2 code?? It raises itself 2 mm up from the pre-defined position (very close to the work piece) - and starts working from 2 mm up. Why does estlcam do this? I can’t find any settings on this. I guess I can just remove it manually?

Is the next Gcode another G0? There is usually a “safe height” setting and the idea is to raise the mill to a safe height to clear the work piece prior to a “travel” move. This prevents leaving mill marks in the piece when moving from one part of the job to the next, or breaking a bit if it runs into something while moving at “travel” rather than “feed” speeds. Movements meant to be cutting are G1 (or G2, G3 etc).

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It also depends on how you’ve set the zero in your CAM. Off the bed or the top of the material.

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I’ve figured it out! I’ve used the motion controller on the LCD to bring the mill close to work piece surface. These steps are somehow influencing the routine, if I dont use the LCD, it starts at the right height. Thanks anyways :nerd_face:

It’s because you are not zeroing out your coordinates then.

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I’m really sorry… I actually don’t understand what you mean by that. I feel like a fish on land when it comes to understanding all this gcode, zeroing and all this. I’m able to make stuff, from different sources - and making the gcode in Estlcam. But this is still quite greek to me…

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The coordinate systems are not intuitive. But basically, it doesn’t really know where the zero is. When you first power it up, it will assuming that is zero until it is told otherwise.

You don’t want to leave it up to chance. There are two common ways to set the zero:

  1. Tell it where zero is. That can be done by sending a G92 X0 Y0 Z0, which sets the current position to zero on all axis. Or there is a “Set Home Position” or similar option in the LCD. You can also put the G92 at the top of the gcode (the test crown does that). If you do that last option, then you always start the gcode at the 0,0,0 location.

  2. With endstops and a Z probe. AKA “homing”. If you do it this way, you home XY, and that will be set where your endstops are. Then you jog to your workpiece (with the lcd) and home Z, using your touch plate. There are a few more steps to this, because your workpiece probably isn’t where your endstops are and you need to compensate for the thickness of the Z probe.

By far the easiest is to just put the G92 X0 Y0 Z0 at the start of your gcode and just always start the file at the origin.

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I explained this analogy in one of my classes:

Zeroing out your coordinates is like setting the start line in a race. When you turn on the machine, where ever it starts is the start line. If you use the LCD or computer to move it, you are moving away from the start point, but the start point is in the same place it was. When you start the race, you have to return to the start line. Zeroing out your coordinates moves the start line to where you currently are.

Physically moving the machine without the LCD or computer is also moving the zero point/start lone

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just wanted to add that learning this concept it extremely important. If you are not aware of your zero, then you could end up hitting hold downs or crashing the machine. 1/8" endmill plus steel bolt means either chips from the bolt flying very fast, or a piece of carbide endmill flying towards your eyes. please be safe.

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Heh.

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Gee - I have some screws that look just like that… must have been a bad batch from the factory :innocent:

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Your avatar looks like you might have some nuts that look like that, too…

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Thanks a lot for your patience! I’m going to keep knocking my head enough against the wall so that one day it’ll sink in.

Looks Norse to me…

Reminds me, binge watched Ragnarok on Netflix recently. Why are the gods homely while the giants are models? Made me wistful for some Beowulf/Grendel action, where the monsters were damned monsters… And for a bit of fun, find Almighty Johnsons on Netflix. Incarnations of the Norse gods in New Zealand…

Here is a good video explaining G28 and homing with the micro switches. Worth a watch.