Setting Z zero when using 4th axis

[tspinetti]

I'm running my first part using a 4th axis and learning as I go.  But I'm stumped about setting Z zero to a part that is not on a horizontal plane.  Do you set Z zero to the top of your material before or after rotating to the machining orientation?  Or is there another method that I'm not thinking about?  I did a quick forum search but didn't find anything on this.  I realize I could pick an arbitrary point anywhere above the material but I need to control the depth of the hole in relation to the top horizontal plane.  See the Shaft Hole Ops setup in the attached file.

[hyperbolicindustries]

Does your control have TCP and DWO? if not your going to have to set you origin point at the center of rotation of your other axis's.

[a.laasW8M6T · Accepted solution]

Hi, 

What machine are you using, this influences the work flow a little bit.

I'm guessing maybe a Tormach?

If thats the case you will always need to be programming from center of rotation.

So the WCS for your part needs to be on the YZ centerline of the rotary axis.

then you can  set your part horizontal then use tool orientation to move the part.

I'm not sure how you are going to accurately locate the part on centerline as I do not know how you are planning on holding onto it.

So Ive uploaded the file with just that setup modified, Its up to you to figure out how to hold it.

i've also uploaded a version that machines pretty much the entire part on the 4th axis in one setup and a screen cast explaining a little: https://autode.sk/3IJ46HF 

Pic of how I Regularly hold onto stuff like this

[tspinetti]

My machine control is PathPilot.  Not sure what TCP or DWO is so I'd say PathPilot does not have these features.

[tspinetti]

Yes, I have a Tormach.  I understand what you are saying and will give it a try.  For the top and bottom Ops I referenced Z from the top of the stock but obviously that doesn't work when locating on an inclined plane.  The center of rotation method makes sense.  Thank you.