Snuggly's Plasma Build

Are you running master branch?
Do you have home switches on both sides of the gantry?
If the answer to these two questions is yes, and you are properly configured in your INI file, then you should just be able to do a "home all"

You can check the function of your home/limit switches by using Halmeter to monitor their inputs to your control without needing to move anything. Get the switch states correct by manually operating them (finger) before you try to move the machine. If you must move anything mechanically disconnect the motor(s) before manually moving it.

In general you want to home Z axis first to top of travel (maximum Z clearance). Then home any single drive axis to a safe place and then finally home the dual drive axis. This should give you two working axis to make sure you have all the directions sorted out before going to the hard one that can really cause mechanical damage to your machine.

John

@rodw: I am running 2.8 master branch with end-stops/home at each of of every axis. The problem was that I hadn't added in HOME_SEQUENCE = 0 to my x1 & x2 scripts so it would only home one side of the axis at a time.

@Islander261: I did as you suggested but my switches aren't showing any signal at all. I made sure to disconnect the motors before moving the machine manually, don't need a fried driver. I don't know if these DM542A drivers have any protection.

All of my switches are normally closed (to mitigate any interference from the HF start). Here's my current machine files for you all to check out. I still haven't been able to fire the relay; I'll make another video walking you all through the endstops and relay wiring.

You must fix your limit switches so you can see the pins with Halmeter. If Halmeter can't see any changes in pin state then your controller can't either. Can you see all your I/O pins in Halshow? Can you see any of the switches operate using a VOM at the 7i96 connectors? The best use of your time at this point is to make a wiring diagram for your limit switches and then verify you actually wired it that way. I am of fto market now and won't be back until Sunday night.

John

@ Islander261: I have double checked the wiring on my limit switches, it's more than likely a problem with my software setup.

snugglylovemuffin wrote:

@rodw: I am running 2.8 master branch with end-stops/home at each of of every axis. The problem was that I hadn't added in HOME_SEQUENCE = 0 to my x1 & x2 scripts so it would only home one side of the axis at a time.

Your ini config is wrong. You joint axis is on joint 0 and 1 so you need to haveYou must also include a HOME_SEQUENCE value for the other joints (2 & 3)

For joint 3, I would useand for joint 2, use
Read the docs carefully
linuxcnc.org/docs/2.7/html/config/ini-ho....html#_home_sequence

Umder the configuration, I have suggested, your Z axis will home first to clear anything on the table, then your Y axis will home, then your 2 gantry joints will home.

You could also use HOME_SEQUENCE = 0 for joint 3 and it will home with the Z but I found it was much safer to lift the Z axis before any other axes moved.

At the moment, there is nothing to tall Linuxcnc to treat joints 0 and 1 as a single axis so your homing cannot work!

I figured the sequence number had to do with order. I was able to get the gantry moving together but I don't know why my endstops aren't working.

I wired up the endstops to trigger low, gave them 24v. It's literally two wires, +24v to the common pin and NC pin to the TB3 header. It must be a software issue, I haven't found any literature that says anything about how to "wire" these switches in HAL

Here is an example of setting up hoe, max and min limits for a single joint using a 7i76e taken from this example config I shared forum.linuxcnc.org/47-hal-examples/34072...ranch-gantry-example

Take the time to use halshow which is available from the menu system in axis and gmoccappy. As Islander261 has said, watch the 7i76e pins that you have used for your limit switches using this tool and confirm they toggle on and off when you trigger them by hand. Then connect them to joint.n.neg-lim-sw-in and joint.n.pos-lim-sw-in as shown above.

Then , adjust the working size of your machine so it falls inside your limit switches for each joint and axis using the ini file settings
Remember, you machine will error if a limit switch is hit during operation so you might need a bit of trial and error to maximise your working envelope without hitting limit switches.

About homing.

I have plan's to do homing with a component in the future. I have had 2 incident's.

1. Milling machine :
The mill was drown into the table because of user fault. Oke he restarted linuxcnc. But he needed to home first.
He had a problem, because machine can not move with mill drowned into the table. So solution is 2 separate
startup icon's. One for homing on limit switch, one for homing directly without switch.

2. Plasma machine :
My tables have a border finish, like an edge. The z-axis need to be above the border height, if not, torch will hit
the table border while homing x and y axis. So solution is 2 separate
startup icon's. One for homing on limit switch, one for homing directly without switch.

Final solution :

Component homing :
This is a button in the program that homes when you want to do. Machine will alway's move.
And we are satisfied.

I believe that both of those problems become non issues if you use the convention of having the machine home the Z axis first before it homes the other axis.

And most machines can be jogged before homing. Some gantry setups may be exceptions to that rule. But even those can usually jog the non slaved joints before homing (in other words move the Z out of the way).