# NEED help with setup cnc lathe



## rick-b (Apr 17, 2019)

Hi,

I have a little Neutron CJK0640 cnc lathe with a WA-31DT controller. The thing I am trying to get my head around is the machine doesn't have a machine zero to start from, I'm told it has a floating zero. Can anyone give me an idea how to set this up? The manual I got with the machine is in "chinglish" so it's of little help.

Rick


----------



## JimDawson (Apr 17, 2019)

For the Z, just zero at the end of the work, I normally take a face cut and use that for zero, Z+ would be away from the chuck.  For X take a cut with the MPG, measure the diameter and plug that number into the controller as a positive number, depending on the controller you might have to enter the radius.  The X zero should normally be the spindle centerline.

You may have to set zero for each tool, or maybe you can set a tool offset for each tool, depending on the controller.  This would be your G54 position, safe X and Z would be a G53 position for tool changes.


----------



## mmcmdl (Apr 17, 2019)

Nice looking lathe !  Jim , it's been awhile but I think I remember a G code and a U0 W0 to send to a home position . This was known as machine reference 0 . Is this still the norm ( at least on the Fanucs ) ?


----------



## rick-b (Apr 17, 2019)

Thanks Jim, I will give that a try. So does that mean I do not have to worry about not having a machine zero?

mmcmdl, Thank it is a nice machine I got it cheap to cheap to not buy it. The machine doesn't look to have U0 W0 I tried it and all I got was an error. Gcode wise this is what I* have.

G functions of WA-31DT series numerical control system are as follows:

Modality G00 Fast locating.
Modality G01 Line interpolation.
Modality G02 Clockwise circular interpolation or spiral interpolation
Modality G03 Anti clockwise circular interpolation or spiral interpolation.
G04 Time delay
G09 Servo angle-specified stop and positioning
G20 Independent sub-program call
G22 Independent of program definition
G24 Independent of program definition completion, and returning to call
program
G25 Skip processing
G26 Block calls processing (sub-program call in the program)
G27 Endless loop
Modality G30 Multiply factor cancels
Modality G31 Multiply factor definition
G47 Initiating short line smooth transition function
G48 Cancel short line smooth transition function
G53 Cancel zero bias
G54 Absolute value zero bias
G55 Relative value zero bias
G56 Current point zero bias
G71 Internal (external) diameter cutting compound cycle
G72 End surface cutting compound cycle
G73 High speed deep hole processing cycle.
G74 Return to reference point (mechanical origin).
G75 Return to the presetting cutter point.
G76 Return to the program zero from the current position.
G78 Fine boring cycle.
G81 Center hole drilling cycle
G82 Center hole drilling cycle with pause
G85 English system rigidity threading cycle
G86 Boring cycle (auto-return)
G87 Counter boring cycle.
Modality G90 Absolute value mode programming.
Modality G91 Increased value mode programming
G92 Setting up program zero
G96 Constant linear speed cutting
G97 Cancel constant linear speed cutting
G98 Cancel feed of each rotation
G99 Setting feed of each rotation


----------



## mmcmdl (Apr 18, 2019)

Little different from the Fanucs I ran . The home code was G98 U0 W0 . This took you to a safe tool change spot . Mechanical zero . Yours looks to be G74 to mechanical zero . Where's your cutter comp ? Don't see it ???

Edit . On the Fanucs of past , It was G98 U0 W0 . This cancelled cutter comp and rapided to mechanical zero for tool changes . Your program zero can be set anywhere following Jim's post . I distinctly remember G74 was a peck drilling cycle on Fanucs . Have you tried G74 with U(x) W(z) 0 ?


----------



## JimDawson (Apr 18, 2019)

rick-b said:


> Thanks Jim, I will give that a try. So does that mean I do not have to worry about not having a machine zero?



Yes, that is correct. Everything can be referenced to the part zero, or an arbitrary point in space.  In reality, if you set a zero point at the work, and can get back to that point with each tool, that everything should run fine.  I have to say that after years of running milling machines it took me a while to get my head around the lathe coordinate system.  My knee mill has a floating zero, but no tool changer.  So the machine 0,0,0 is always set to the work.  On my lathe I use two coordinate systems, M(achine)CS and W(ork)CS.  The only reason I did it this way is because I have a tool setter and needed a fixed absolute reference to generate the tool offsets, but each tool could be set to the work.  Other than that the only thing I use the MCS for is a location reference for a safe X and Z position so the turret can rotate without smacking a tool into something.  I use G53 to switch into MCS mode for tool changes, and G54 (WCS) for cutting.

I hope I haven't confused you too much here.   

In reading through your G codes list, I see some odd descriptions and what are apparently typos.  Unless I missed it, I don't see any single point threading function.


----------



## rick-b (Apr 18, 2019)

Jim,

That has helped a bit to get my head around it, I will give it a go over the weekend. I think my confusion also comes from my VMC with it I just push the button and it goes to zero and I'm starting to think the lathe is not going to be that easy. Yeah sorry about the typo's in the list I cut and pasted it straight out of the manual. The whole manual is like that which doesn't help. As for the threading I haven't got that far as yet but there is a section in the manual about threading  so I know/think it can do it.

Rick


----------

