Hello Guest it is March 28, 2024, 11:05:54 AM

Author Topic: Table Orientation and Homing  (Read 810 times)

0 Members and 1 Guest are viewing this topic.

Table Orientation and Homing
« on: November 22, 2022, 05:38:29 PM »
Hello Everyone.  New to CNC and I just picked up a GR3 Carriage and Rail 2x4.  The guy I bought it from has a very different perspective on zero and homing that pretty much everything I have seen and read.  Machine home should be front left and z up from the front of the table.  For some reason, this machine was set up to home back right and z up.  When I am looking at the machine running, it is moving opposite in Mach 3 than physically on the machine.  I am having a terrible time figuring out to correct this.  I have figured out how to make it work, but I really don't like it.

What I want to accomplish is setting machine zero with proper orientation, then setting soft limits because I do not trust the mechanical switches (most of the wiring is suspect) and the z does not have a working limit switch.

I have watched hours of videos, but nothing covers how to do this.  I watched a video on running a spoil board surfacing operation and was able to get it to work (mostly), but I am really uncomfortable with this setup.  I feel that I could inadvertently run the machine past its limits because both me and the machine are lost.

Any assistance anyone could provide would be greatly appreciated.

Offline Graham Waterworth

*
  • *
  •  2,668 2,668
  • Yorkshire Dales, England
    • View Profile
Re: Table Orientation and Homing
« Reply #1 on: November 22, 2022, 08:15:08 PM »
Are we talking about a router?

If so then the long axis is X and as you look at the machine it should run to your left and right.  It should home to the right end.

The Y axis runs to and away from you and should home at the back.

Z axis runs up and down and homes at the top.

If you set it like this then home the machine and zero out the DRO's when you move away the dro's should read minus values.

To set the softlimits switch to machine coords and use these values in the table.

Table should look something like this.
Without engineers the world stops

Offline Graham Waterworth

*
  • *
  •  2,668 2,668
  • Yorkshire Dales, England
    • View Profile
Re: Table Orientation and Homing
« Reply #2 on: November 22, 2022, 08:26:04 PM »
Here is a description of how machine are set up :-

https://www.machsupport.com/forum/index.php?topic=1725.msg9977#msg9977
Without engineers the world stops
Re: Table Orientation and Homing
« Reply #3 on: November 22, 2022, 08:33:01 PM »
Hello Graham.  Yes, it is a router.  Actually, my long axis is Y (front to back) and X is left to right.  When I look at Mach 3 the table view shows machine zero at the front left, but my machine zeros at the back right.  I am not in my shop at the moment, so I'll have to check in the morning, but I'm pretty sure that my numbers are opposite of yours.  Soft Max for Y is 48, for X is 24 and Z is zero.  Soft Min is 0, 0, and -4 respectively.

When I am watching the machine run in the window in Mach 3, X and Y are running backwards, but the machine is physically running correctly.  If i jog it with the keyboard, the keys accurately match the machine movements.  I would think that if the down arrow moves the gantry towards me, then M3 knows which direction the machine is going, but it is reverse in the view in M3.

I will change my settings tomorrow and post back the results.
Re: Table Orientation and Homing
« Reply #4 on: November 22, 2022, 08:40:30 PM »
Here is a description of how machine are set up :-

https://www.machsupport.com/forum/index.php?topic=1725.msg9977#msg9977

Graham, my machine runs exactly opposite of this.  Is it wired wrong or something?  The interesting thing is that I used VCarve to make a drawing and following the steps in a video, I was able to successfully create the GCode and do the carve and it came out right side up.  I don't know if it was inverted horizontally because it is symmetrical.

Should I just start from scratch or is this setup able to be corrected?

Offline Graham Waterworth

*
  • *
  •  2,668 2,668
  • Yorkshire Dales, England
    • View Profile
Re: Table Orientation and Homing
« Reply #5 on: November 22, 2022, 09:24:03 PM »
It all depends on you.

It is better to have the machine the same as the rest of the world so if you use some code or a drawing from elsewhere the chances are it will work.

Its an easy fix, move the home switches to the correct end update the softlimits and that's about it.

« Last Edit: November 22, 2022, 09:29:32 PM by Graham Waterworth »
Without engineers the world stops