Centroid Community CNC Support Forum

Hello,

I was trying to see if anyone else has tried to configure the z axis in the follow manner on the Forum but did not find anything.

I have a DIY router I built. IT is a ganry style with the y table moving below and the x moving across the gantry and z moving up and down on the x carriage. I am trying to make it so after the machine homes, x to the bottom left, y to the bottom left, z to the top. the machine coordinates are x0, y0 and z180mm (Max travel) . I want it so that any jog in the positive direction moves the spindle in relation to the table in the + (Increasing) direction.

What is currently happening after the home sequence. It is setting x0, y0 and z0. And only allowing me to move/show z in the negative direction.
Thanks in advance!

Arin

What you describe is exactly what is supposed to happen.
Those are the machine coordinates. Once homing is complete, move your bit down to the table and set WCS Z zero at the surface. Then move your bit to the top of the Z travel and you will have your positive position.

Gary, unless I am misreading the OP's post, he seems to require the spindle Z axis to home at the top of its travel (correctly setting machine zero) whilst wrongly expecting a +ve Jog to move downwards in a positive direction. Convention is of course that -ve Z axis moves are down and +ve are up

arinchang wrote: ↑Mon Jul 12, 2021 6:38 pm Hello,

I was trying to see if anyone else has tried to configure the z axis in the follow manner on the Forum but did not find anything.

I have a DIY router I built. IT is a ganry style with the y table moving below and the x moving across the gantry and z moving up and down on the x carriage. I am trying to make it so after the machine homes, x to the bottom left, y to the bottom left, z to the top. the machine coordinates are x0, y0 and z180mm (Max travel) . I want it so that any jog in the positive direction moves the spindle in relation to the table in the + (Increasing) direction.

What is currently happening after the home sequence. It is setting x0, y0 and z0. And only allowing me to move/show z in the negative direction.
Thanks in advance!

Arin

Hi Arin,

When you post, first and foremost, always post a FRESH report. F7 Utility, F7 Create a report. (REQUIRED) What it contains is all your machine settings.
Better yet, please follow this post, provide all the details about your machine, axis drives, axis motors, home switch type and location (even better pictures of your switch placement) The more information you provide, the better suggestions we can make
viewtopic.php?f=60&t=1043

We can not "SEE" what you "SEE"

The way your Z axis home should work, is Z+ travel is at the top, Z- is the bottom. Limit switches on Z are usually placed at the upper most (Z+) end of the axis travel. In the Wizard, under homing and travel, you tell the Wizard you are homing to switches. Then in the soft travel limit boxes, if you home to Z+ then you set your soft travel limit in a negative value. Say your Z moves DOWN (Z-) 5 inches, then you would put -5 in the Travel Limit (-) box.
On X and Y, if you have the limit switch on the negative and of the travel, then you would put a POSITIVE value in the Travel Limit (+) boxes.
For example, if you home X to negative and, and you have 25" of travel in the positive direction, you would put 25 in the Travel Limit (+) box

Remember, when a machine homes, the home position is viewed in the MACHINE POSITION DROs (Press Alt d to toggle the DROs from Work Coordinate to Machine Position) If you previously set a PART ZERO position, when you home the machine the next time, the DROs are in the Work Coordinate system (G54 usually) and will show the distance TO the last part zero position from home.

I personally do not follow your statement: "the machine coordinates are x0, y0 and z180mm (Max travel) . I want it so that any jog in the positive direction moves the spindle in relation to the table in the + (Increasing) direction."

Please take the time to clarify and why. Perhaps take a short video showing homing and then what the machine is doing and what you want it to do.
Go to the Homing Travels Wizard screen and show that too. Post it to YouTube, list it as UNLISTED and share a link here.

Hope some of this helps, I don't know how much you know, I don't quite understand what you are trying to accomplish.
Marty

You might want to look at this post about machine tool coordinate systems - viewtopic.php?f=64&t=3638

I think Gary is right, and the OP is just confusing machine coordinates with local work coordinates.

Machine Coordinates zero should be where the machine homes to (e.g. Z at top of travel).

When the OP describes wanting a coordinate system where Z0 is at the table surface or work surface, that is presumably for the purpose of running CNC programs.

Use the Part Setup screen (F1/Setup -> F1/Part -> F1/Next Axis (twice) to set the local work coordinate zero wherever you want it.

Thank you.

Thanks for all the replies. Sorry newbie poster. Per Marty's insight I will upload my controller, pics of my machine etc this weekend.

Arin