[destroyer125]

Hello all,

I work for a company that has a small machine shop in the back to produce odd end parts for their products. I am not a machinist by trade but I have recently started using the machines. The company no longer has a cnc machinist on staff and outsources all the production work to an outside company so no one around has an experience with these. I have experience programming G-code and can run the Fadal VMC 4020 in the shop without problems but this is my first experience with any of the CNC lathe in the shop. We have a Yang ML-25A with a fanuc 0T controller and I cant seem to figure out the tool/work offsets and how the controller on the machine works. I have a fanuc manual for it but I cant seem to make heads or tails of a lot of the info in it. I also cannot get it to take single line g-code commands in MDI to get it to move to desired locations (Maybe I have the knob set in the wrong setting, am I looking for something other than MDI). Also, the controller does not show which tool is currently in position. If I type in T0101, nothing happens, even after hitting output start. In the pictures below, I fiddled with the offsets for tool #1 and those obviously incorrect because the x offset should be negative.

I believe the last guy to run the machine was setting all the tool offsets off the jaws of the chuck. Should I set all the tools off the face of the jaws? And then set the work shift will shift the work offset by that distance, this would be the distance to the front of the part?

This controller does not have a measure function to make offsets easy. What kind of data should I be entering to set these. The machines home position reads x0 z13.92

Any and all help is much appreciated!
Thanks

[Hezz]

This is just a table of offsets for the different tools on the turret. I think the confusion may be that it looks like that it is assigning different offsets to different g codes. The way you set these values is that you manually face a piece of stock to call it your program zero for the first tool to set it's Z and then measure the stock with micrometers and divide that number by 2 to get the X offset. While touching off on the outside of the part. Then you need to do this with each tool in the turret so each has it's own Z and X offset.

The column that says offset number may be just a program code that the program calls to get the offset. But these codes should be changed to something other than G codes I believe. Otherwize the program may be confused. Is the letter G in the offset number name changable?

Might be a good idea to go over the manual in detail.

With more modern machines when you call the tool in the program the machines controller automatically goes and gets the offset for that tool. But in some of the older machines you have to call the offset in the program because the controller does not automatically get the offset. Because of this the offset may need a unique name. You will need to look and see how the programming is supposed to work for this lathe. It may be that in the program that you call a tool change and than an offset change and then the code following the offset change will correspond to the one you want with the tool your using. Maybe you can use those G codes since the controller will know that the name of the offset following the offset call will be for an offset instead of calling for linear or circular interpolation, etc.

Another thing that may be confusing is that on older machines these offsets can be thought of as relative to the program zero. So they need to be setup when ever there any kind of change of program or setup. On more modern machines these offsets may be more permanent offsets that are relative to the machines tool's touch off post. They only need to be changed if one of the tool's is moved. And in this case of the modern machines you put in the program zero separately and the machine calculates all of the differences between program zero and the tool touch off zero.


Paul