Auto Homing Squaring pairing using ZRI ?

[Proidea]

Dedicating an input of the Acorn for the ZRI from the X, YMaster and Z and another for the ZRI from the Y Slave, is possible to use the Auto Homing and Auto Squaring with Software Pairing?

Thanks,
Henry

[cnckeith]

with a custom home file anything is possible

[Proidea]

Thank cnckeith for your reply.
In the meantime, I had time to think about it
Now I think it's not possible for these reasons:
According to the relative Acorn instructions, there are some conditions to be satisfied:
1)The Gantry Home Switches must not be square to the machine.
In other words: they do not have to trigger the inputs synchronously.
Considering I can set the output resolution of the Z marker pulse from my drivers, let say 2500 pulse per revolution.
Considering too that my gantry is in its relaxed position absolutely squared (impossible)..
If the my math is not wrong, there is a 1/(2500*2500) = 1 every 6250000 the probability that the Z marker pulses from the two encoders (Y Master and Y Slave) are synchronous, triggering the relative inputs at the same time. - So:

Condition # 1 : Good chance that's possible - in other words it means that it could be impossible to satisfy

2) From the step by step instructions:
Step 5. Unbolt the master home switch and offset it AWAY from the gantry .025” (this distance can typically be up to two thirds of the measurement made in step one, bigger machines can usually have bigger distances).
Step 6. In the Wizard set the Master Axis Alignment distance equal to the amount you moved the master switch away from the Gantry. In our example set the Master Axis Alignment distance equal to .025”

- I do not know when the Z marker will trigger - it means that I do not know the distance - it can be from zero to 10 mm (one revolution of the motor X lead of the ballscrew(10mm)=10 mm.

So: condition # 2 impossible to satisfy

What do you think?

Henry

[cnckeith]

hello. those instructions are for the Wizard auto generated home program.
If you create your own home program and method (and toss those instructions out the window) you could do zri with auto squaring its totally possible. (oak and allin1dc essentially use this method for auto squaring)
resources:
- 'toaster' on the forum has created his own custom auto squaring home program, i think he posted it as well. you could look him up and his posts to learn what he was doing.
- read about Centroid macro programming here. https://www.centroidcnc.com/centroid_di ... amming.pdf

[Proidea]

Thanks again cnckeith,

I'd happily throw the instructions out the window, but I'd like to find something right about it first.

I searched for a long time for some toaster posts, I haven't found anything on the subject. From what I've read from his posts, he's always referring to stepper motors. Nothing about encoders and related ZRIs. Or was your suggestion to get some macro programming examples?

I also carefully read the manuals of OAK and All in one, and Macro Programming. Again nothing on the subject.

Could you please give me more details? -

Thanks in advance!

Henry

[tblough]

If you write your own homing routine, you can control what actions happen on what inputs. Can't really provide more details than the overview on macro programming until you tell us what inputs you have defined and how you want your homing routine to work.

Here are examples of how others have done it:
https://centroidcncforum.com/search.php ... mit=Search

[cnckeith]

hello. i didn't mean toaster used ZRi, i was citing his work as an example of a custom auto square home program. the auto generated home program is looking for these two inputs "HomeAll" and "SlavedHome", to use other inputs in conjuction or in place of as tom suggests requires a custom DIY home program. the custom program would use home input to "get in the ball park" and then seek the zri pulse to arrive at an exact position each time.

DIY home program outline would be as such.

move Z to home switch or homeall triggers
back Z up until Zri input is triggered
Set Z home

move X to home switch or homeall triggers
back X up until Zri input is triggered
Set X home

move Y to home switch or homeall triggers
unpair Y
backup master until Zri input is triggered
move slaved axis until home switch or homeall triggers
backup slave until Zri input is triggered
move slave the squaring adjustment amount
repair
set Y home

[Proidea]

Dear cnckeith,
I thank you very much!
after your last suggestion my head started processing the data received and something is came out.

I put down the data I have in excel, setting the maximum possible distance in mm between the triggering of the home switch and the triggering of the ZRI (one revolution of the motor multiplied by the lead of the ballscrew).
I then calculated the movements step by step and the consequent positions reached by the master side and the slave side of the gantry. And that's what came of it.
(I have not found a way to insert tables in the post, so I am attaching a screenshot from excel)
I hope it is understandable...
please, tell me if I'm wrong!

Henry

[cnckeith]

looks like you are on your way!