Need Help!- Home again Home again Jiggety Jig. Well Not Just Yet!

[Mr.Chips]

Using Mach3
My machine is a fixed gantry, and I want my table to be home at Y +19 and X +16. At this point it will be the most convenient to load material and change tools. See Drawing below.

In the MotorHome/Soft Limits table I think I have input it to have it home where I want it to. Is it correct? See Drawing below. If not what should I change?

Well it must not because after I set this and click OK I still can drive past these limits with the arrow keys.
Or, do the arrow keys override the Soft Limits?
Or is there something else I need to do to activate the MotorHome/Soft Limits?

Once the MotorHome/Soft Limits are set will they hold the settings during turn off and on?

[ger21]

Do you have home switches? Do you want the Y19 X16 to be 0,0? Or just have the machine go there when you home it and have the home switch location be 0?

Putting those values in the home offset box just makes those the values when you home. If you have home switches at your 0,0, position, you just need to tell the machine to do a G0 X16 Y19 after homing. this can be added to the button to do it automatically. I think that's what you want. If you put your home switches at X16 Y19, then you would put those values in like you have shown it. Not sure how you actually want to go about it.

[Mr.Chips]

Originally Posted by ger21 Do you have home switches? The mechanical switches are not connected right now. I am just want to set SOFT SW's at this time. I saw a demo on YouTube of Hoss using the Soft Switches and the machine would slow down as it approached the Soft Switches and stop when it arrived at those preset points, and never touching his limit switches. This is what I want to do. Do the Soft Switches have to be set each time the machine is powered up? By going to 0,0 and then moving to Y19 X16 and setting them, or is it held in a file. How does that work? Do you want the Y19 X16 to be 0,0? Or just have the machine go there when you home it and have the home switch location be 0? I do not want Y19 X16 to be 0,0. 0,0 is in the opposite corner. I want it to home at Y19 X16. I am only talking about Soft SW's. Putting those values in the home offset box just makes those the values when you home. When you say "just makes these values when you home" do you mean it moves to Home which is Y19 X16 when you Home? Or do you mean when ever you press Home it assigns Y19 X16 to the position where ever you are on the table? If you have home switches at your 0,0, position, you just need to tell the machine to do a G0 X16 Y19 after homing. this can be added to the button to do it automatically. I think that's what you want. If you put your home switches at X16 Y19, then you would put those values in like you have shown it. Not sure how you actually want to go about it.

I need to understand what you have said in the previous sections before I go into this section.

Sorry to draw this out so long, being a slow learning new user I need to know what you are describing. I am unsure of the terms Home, 0,0 and 0 It seems they mean different things, and could mean the same thing.

[ger21]

Sorry, but I didn't have time to elaborate earlier. I'm still a little unsure of what you want to do. Are you only concerned with setting up the soft limits? There is a button on the program run screen to turn them on after you set them in the homing/limit window. It's under the DRO's on the right side, next to the bottom left corner of the toolpath display. Once you turn on this button you will no longer be able to jog past those positions. Once you turn on the button, they will stay set when you close and restart mach3.

Now are you also asking how to get the machine to go to X16 Y19? It looks like by putting the numbers you have in the G28 homing boxes, it'll home where you want when you do a G28.

Disregard my other comments because I was going in a different direction. Let me know if this doesn't clear things up.

[Mr.Chips]

QUOTE=ger21;427088]Sorry, but I didn't have time to elaborate earlier. I'm still a little unsure of what you want to do. Are you only concerned with setting up the soft limits? There is a button on the program run screen to turn them on after you set them in the homing/limit window. It's under the DRO's on the right side, next to the bottom left corner of the toolpath display. Once you turn on this button you will no longer be able to jog past those positions. Once you turn on the button, they will stay set when you close and restart mach3.

Disregard my other comments because I was going in a different direction. Let me know if this doesn't clear things up.[/QUOTE]

I will focus and not ask so many questions at once..

Yes I want to set the soft limits.

I have set them as shown below in the Motor Home/Soft limits, and pressed OK. If you see errors there please let me know.

I found the button you are referring to above and pressed it when the router was in the center of the cutting area.

Now I cannot move the router in either the -X or -Y direction from there.

Does this mean that I have to press the button you were referring to again and toggle the soft limits off then drive the machine to 0,0 and then press the button again then the soft limits would be correct?

Does this also means that before I turn the machine off I must go to 0,0 for the soft limits to be properly set when it is turned on the next time?

[ger21]

You should not have your soft limits and home position set the same, i should have said that before. Set your soft limits at least an inch past your home position.

Yes, toggle them off and jog away, then turn them back on.

You should be able to turn it off in any position and they should still work fine. But keep in mind that they will always be relative to your arbitrary 0,0 position. Using "Real" home switches will give you a consistent soft limit location.

Does that make sense?

[Mr.Chips]

Originally Posted by ger21 1. You should not have your soft limits and home position set the same, i should have said that before. Set your soft limits at least an inch past your home position. 2. Yes, toggle them off and jog away, then turn them back on. 3. You should be able to turn it off in any position and they should still work fine. But keep in mind that they will always be relative to your arbitrary 0,0 position. Using "Real" home switches will give you a consistent soft limit location. Does that make sense?

OK, No 1 and 2 is working and understood. See new Motor Home/Soft Limits table below. And doing a G28 in the MDI Alt2 Input drives it to x15 Y18 just as it should. Any shortcuts to input G28 rather than changing screens form the Program screen?

Now as for No 3, I have a couple of things I am yet to understand.
What is the “arbitrary 0,0 position”?
"Real" home switches, are you referring to micro switches? Would they be adjusted to exactly the 0,0 position?

[ger21]

Originally Posted by Mr.Chips Any shortcuts to input G28 rather than changing screens form the Program screen?

You could modify the screens and add a button to do it, but other than that, I don't think so.

Originally Posted by Mr.Chips Now as for No 3, I have a couple of things I am yet to understand. What is the “arbitrary 0,0 position”? "Real" home switches, are you referring to micro switches? Would they be adjusted to exactly the 0,0 position?

Arbitrary meaning that without physical (real) home switches, you have no way to get a repeatable 0,0. Your 0,0 will be wherever you are when you hit the "ref all" button.

And you can put the home switches anywhere you want. That's what the "home offsets" column is for. If you set the home offsets to -1, then your 0 will be 1" away from the switch. You could also put your home switch at X16 and set your home offset to 16, and have the machine home to that end. If you did that, then the ref all button would do what you're doing with G28.

[Mr.Chips]

Originally Posted by ger21 You could modify the screens and add a button to do it, but other than that, I don't think so. Arbitrary meaning that without physical (real) home switches, you have no way to get a repeatable 0,0. Your 0,0 will be wherever you are when you hit the "ref all" button. And you can put the home switches anywhere you want. That's what the "home offsets" column is for. If you set the home offsets to -1, then your 0 will be 1" away from the switch. You could also put your home switch at X16 and set your home offset to 16, and have the machine home to that end. If you did that, then the ref all button would do what you're doing with G28.

Arbitrary meaning that without physical (real) home switches, you have no way to get a repeatable 0,0. Your 0,0 will be wherever you are when you hit the "ref all" button.
I have jogged the router all over the table and when I hit Zero, it goes back there every time, perfectly repeatable. But I think you mean repeatable when turned off and back on when not in the 0,0 position.

I have never hit the Ref All button. Don't know what it is for it is not in the Mach3 guide index.

Think I need to take another look at my micro switches, at least the X, Y and Z Home ones are needed.

[ger21]

Originally Posted by Mr.Chips But I think you mean repeatable when turned off and back on when not in the 0,0 position.

Correct. Regardless of where it is when you turn it off, there's no guarantee it will be in the same place when you turn it on.

The ref all button "homes" all the axis to the home switches. But if you don't have switches connected, it will zero all the axis at once. I didn't realize that you must be zeroing each axis separately.

[Mr.Chips]

Thanks Gerry,

Thanks to you I have a much better understanding of MotorHome/Soft Limits and their function.

Will look at my micro sw configuration and see about intergrating it into the Homing. Then that portion will be complete.

Next time
Hager