Z offsets

[slideleft]

Can someone please explain to me why Z coordinate offsets are opposite of what I would expect them to be? e.g.; negative value for higher position, positive for lower.
Thanks,
Jeff

[-Chris-]

Theres not enough info to answer your question. though in my shop we have several Haas machines and a multicam router, The Haas has a standard system while the router is just oposite requireing positive numbers to increase depth of cut Is it machine spacific?

[slideleft]

Well,
I have 2 operations for my current part. The 1st using G54 offsets, Z offset=0. The second op is in a fixture .5" higher and using G55 offsets. My question is- Why isn't the G55 Zoffset a positive .5"? I have to input -.5" to get the proper position.

[kendo]

I think its because the offset is measured from the spindle face
The distance from the spindle face at machine zero to your G55 is .5" less than G54

[Geof]

Parameter 57, COMMON SWITCH 1 has an entry #25 called NEG WORK OFS and the description reads:

"Selects use of work offsets in negative direction"

I think this changes the sign on the entry in the Offsets Page.

[slideleft]

Geof,
Thanks for the info. I found the parameter but it says it is locked. How do I unlock if I want to?
Thanks

[Geof]

Originally Posted by slideleft Geof, Thanks for the info. I found the parameter but it says it is locked. How do I unlock if I want to? Thanks

Setting 7, turn it off then push E stop and you should be able to change the Parameter.

[slideleft]

Found it Geof. Thanks.