Rotary: Z zero @ center of material. GoToZero buries the bit

[DavidCousins]

Rotary question: Z zero at the center of material. GotoZero buries the bit.

When I press the Mach3 button "GoToZero", the bit gets buried into the wood.

There must be a Mach3 way of using "GoToZero" without burying the bit. I don't know the setting? Any help will be appreciated.
Dave

[4DThinker]

Look in the Material Setup tab on the toolpath side for Home Start Position. If the Z value is zero there, change it to your thickness plus how much over the board you want the bit to be when it starts. This works for me using LinuxCNC. If your machine still insists on plunging to 0,0,0 on start up then it may be a hardware setting. I know the CNC Sharks would do this before they did a recent firmware update for their controllers. I would simply locate my origin OFF the material in a place where the bit COULD touch down to the bottom plane of my work piece.

4D

[DavidCousins]

4D,
I'm not seeing the Material Setup Tab. Also, "material setup" in what software, Mach3 or Vectric?

[4DThinker]

Vectric... Aspire 8 specifically. You didn't mention which Vectric program you used. There is also a material setup option on the top left of the toolpath menu in Vcarve 7.5

[DavidCousins]

I have aspire but it's a lesser version. In my material setup, I have the home work position well above the rotary wood, with z zero at the center of the work. Mach 3 doesn't use that data when I press go-to-zero. Maybe I need to write a macro in Mach 3 to go to x/y zero and a Z of 2 inches

[4DThinker]

If z=0 is the center of your stock the bit will plunge there when it tries to go Home. Can you make your origin point outside of the material? If so then that plunge will be outside the block where it doesn't matter, and then the cut will proceed.

[Leo]

When you setup the workpiece on your machine, where did you zero out the cutter?

You needed to touch off the tool somewhere.

Where did you touch off the tool?

THAT - place is where Mach 3 is trying to drive the tool to.

[DavidCousins]

I think, from the answers, that a macro is going to be the way to solve this problem. So I started a macro question. Thanks for all your answers.
Dave

[dhellew2]

One easy way to set your z-zero manually is to tighten the bit just enough so it won't fall out, move the bit close to the part, slide the bit to the surface, tighten the bit, set z to zero.
Then in your design software set z-zero at the top of the part.

Dale

[Greolt]

David

I think above posters missed your point.

The problem with these silly CNC machines is that they do whatever we tell them to.

You are telling all axis to go to zero and that is exactly what it will attempt to do.

I do a variety of work on the CNC and that includes rotary work. Almost always the Z origin is at the centre of rotation.

I will never use that generic "Go to zero" command. Whenever I press a button (send a command) I think, "What is it I am telling the machine to do?"

So I have one button to send X to zero, one button to send Y to zero, one button to send Z to zero, etc.

Much easier on my old brain to think of one thing at a time, "if X goes to zero will it hit a clamp?" or "if Z goes to zero where will it stop?"

It is an easy thing to modify your Mach screen to have individual buttons for such a purpose.

[DavidCousins]

David

I think above posters missed your point.

The problem with these silly CNC machines is that they do whatever we tell them to.
.......
It is an easy thing to modify your Mach screen to have individual buttons for such a purpose.

Greolt,
Thanks for the reply. You are correct I need to do a little screen mod and a macro.

For the macro, I'm guessing it will only take a couple lines of script.

A long time ago I used your script for auto z zero. I'll take a look at that. I'll bet I can figure out how to adapt it for x and y and omit the z.

I appreciate your comment.
Dave

[IslaWW]

Dave...
If you look at your existing macro, it will probably be something like "G00 X0Y0Z0" remove the "Z0" and you will get what you need

[daniellyall]

remove Z zero from the gotozero button using a screen editor or just use the mdi and type x0 y0 z what ever is safe or just don't use it when you run a code it will always go to the start anyway what would be X0 Y0 Z top of material

[Greolt]

MachScreen is my screen editor of choice.

Here is a screen grab of the settings for the "X axis to Zero" button.

[ger21]

remove Z zero from the gotozero button using a screen editor

The Goto Zero button in Mach3 calls a system function, and you can't just remove the Z zero from it. But you can change the button to execute g-code or call a macro. I think you only get one line of g-code, so a macro is the better choice. I'll reply in your other thread.