CONFUSED! Need help setting Z axis zero on part bottom

[fritter63]

I'm having problems getting my CAM setup right for a part.

This part is bacially sitting in the bottom of the stock, so I want to first surface the stock to thickness of the part, and then do

the rest of the coutouring. Everything seems to be setup correctly in F360, I can see the model positioned correctly in the stock, and

the simulation works as expected. All cutting is done POSITIVE in the Z direction (above the Z plane).

But, when I run this GCode in my machine, and I set Z zero at the bottom of the stock (that is to the table surface that the stock is sitting on),

it wants to treat that Z0 as the TOP of the stock! It starts by moving to negative Z and starting the operations. Is this a problem with setup in

F360? How do I tell it that Z0 is always the bottom of stock?

Picture attached.

I have tried both model orientation and also selecting the Z axis (selected the bottom of the part, and then reversed Z), but still no good.

What am I doing wrong?

Thanks.

[Trigg3r]

Post processor reversing the Z axis values ? Just a guess as I've spent the last 4 hrs in a local brewery tour... 🙂

[davebYYPCU]

That picture has the triad, centre of top of stock, 

Would it need to be on the centre of the base of the stock?

[fritter63]

That's what I was thinking? But I can't find a way to do that and still have Z pointing up.

[Anonymous]

You need to select a point on the stock at the bottom of stock if that is how you are setting up your job. 

Right click on your setup (probably "Setup1"), then choose "Edit" from the drop down menu. You should see points appear on the stock at the corners at top, midpoint and bottom of the stock as well as in the middle of the stock. The setup window will also appear. You may have to rotate the model to see the point at the bottom of stock if you are using the middle of the stock as zero instead of a corner. Click on the point you want the origin to be at and then choose "OK" on the setup window. Points should look as below:

[fritter63]

Thanks @Anonymous

Will give it a try tomorrow!