Lathe offsets

S

Steven657

Plastic

Joined

May 18, 2018

• Apr 16, 2021

• #1

Hi
Can anybody go through cnc lathe offsets with me ,I get confused some times with i/d ,o/d wear offsets and when to use negative or positive .and when you use screw cutting tool in a bore what way to move offset to make thread looser,
Many thanks

 

A

alphonso

Titanium

Joined

Feb 15, 2006

Location

Republic of Texas

• Apr 16, 2021

• #2

Plus makes OD/ID larger. Minus makes OD/ID smaller. Applies to Fanuc, Fagor, Anilam, GE1050. Don't know about others.

 

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Guest

Guest

• Apr 16, 2021

• #3

What happens on a Z offset will vary depending on type of lathe. I have a fixed headstock where if you moved a cut-off tool Z minus the part gets longer, on a sliding headstock Swiss Z minus on a cut-off makes the part shorter. Both are Fanuc, pretty sure all brands are the same.

 

B

Booze Daily

Titanium

Joined

Sep 18, 2015

Location

Ohio

• Apr 16, 2021

• #4

Adjusting a wear offset - will move into the work. ie: OD smaller, ID bigger.
A wear offset adjustment + will do the opposite.

 

H

Houndogforever

Hot Rolled

Joined

Oct 20, 2015

Location

Boring

• Apr 16, 2021

• #5

After disintegrating a 1/4" tap on my newly acquired lathe,I agree those + & - signs can be confusing.
(wow, that sounds like I"m a dick.)what I am trying to say is I'm still calling my son over to help me figure out tool setup on that damn thing.

 

D

Dan from Oakland

Titanium

Joined

Sep 15, 2005

Location

Oakland, CA

• Apr 17, 2021

• #6

Ha Ha- all the above is true except on a machine with a minus side X axis.

 

A

angelw

Diamond

Joined

Sep 10, 2010

Location

Victoria Australia

• Apr 17, 2021

• #7

Booze Daily said:

Adjusting a wear offset - will move into the work. ie: OD smaller, ID bigger.
A wear offset adjustment + will do the opposite.

Click to expand...

Hello Booze,
With a typical Turning Centre, were both boring and OD tools are performing on the plus side of the machine's centre line, adjusting the wear offset in a minus direction will result in both the OD and ID being machined smaller. The inverse occurs when the offset is adjusted in the plus direction.

If the tools operate on the minus side of centre line, then a minus offset adjustment will increase the size of the OD and ID; vice versa if the offset is adjusted in the plus direction.

Regards,

Bill

 

DouglasJRizzo

Titanium

Joined

Jun 7, 2011

Location

Ramsey, NJ.

• Apr 17, 2021

• #8

On most controllers there is a calculator function so if you want an ID larger you would "add" to the offset. If you want an OD smaller you would "subtract." Most controls have a "measure" function so the machine can calculate proper lathe/distance.

 

B

Booze Daily

Titanium

Joined

Sep 18, 2015

Location

Ohio

• Apr 17, 2021

• #9

Oops. I was thinking of wear on a mill using G41/G42.
That doesn’t affect diameter size on a lathe.

 

G

gcodeguy

Hot Rolled

Joined

Jun 17, 2007

Location

Easton, PA

• Apr 17, 2021

• #10

Dan from Oakland said:

Ha Ha- all the above is true except on a machine with a minus side X axis.

Click to expand...

Yup. Set up Fagor control gangsters normally cutting on negative side so can run all tools M3.