Centroid Community CNC Support Forum

I have changed my homing sequence again.

I tried to use m91 for homing my X and Y axis to physical limit switches (NO) (not prox sensor). It would reach the switch and then start reversing but it would not reverse enough to clear the switch... So the "homing cycle cancelled"

In my current/roundabout homing cycle:

I am currently using the M105 to slow jog to until the switch closes and then M106 at a slower feedrate to back off the switch until it is cleared. I do this for both X and Y. This is probably not as accurate

Is there a way I can check for the index pulse after I clear the limit switch? I need the home to be precise to the mm every time and the wheel switch is not accurate enough to just slow jog and wait for it to open again...

Any help is appreciated!

Thanks,
Peter

so you must be using switches made for farm equipment? photos and make model of switch please along with a fresh report.zip so we can see exactly what you got going on and comment..

The machine is actually an envelope cutter haha.

The switch is model 3SE3 120-1D
The switch has both NO and NC contacts.

Hi Peter.
You really need to follow this post: https://www.centroidcncforum.com/viewto ... =60&t=1043

We have no idea what you are working with. We can't "SEE" what you "SEE"
You mention index pulse but you don't provide any information on your axis motors and drives.
Your switch should work. I would wire it NC not NO.
I would use the default homing settings, Automatic Homing Home to Switch. Take out of the .hom file what you put in.

PLEASE take the time to follow the post above. The more information you provide the better suggestions we can make.

Marty

Sorry about the misunderstanding. The index pulse I am referencing is in the M91 and M92 command. In the Mill manual it says :

"After the minus home switch is tripped, the axis reverses until the home switch clears, and stops when it detects the index pulse. When reversing until the home switch clears, the clear state must be reached within 0.25 inches for a linear axis and 45 degrees for a rotary axis or an error occurs."

I am sending pulses to three different Sigma7 drives (X, Y, and Z) made by Yaskawa. I cannot use the automatic homing because it will use the M91 (- move to home) command... And like I said: when the switch is closed, the reverse action (+ direction) does not reverse enough to clear the switch.

Would the "automatic homing home to switch" not use the M91? Now that I think about the index pulse... I think the Acorn is open loop control and the sigma7 <--> motor encoder is closed loop. So there is no index pulse reading by the Acorn...

attached is a screenshot of the schematic.

There is no way Acorn can see the index pulse from the motor encoder like Oak or All in One DC
That said, can you take a video clip of the machine homing so we can SEE what is happening?

Let the wizard create the home file, set for Automatic Homing, Home to switch. Tell it the direction you want to home and let it do its thing.
IF you need very precise homing, you will have to come up with another method

I think my custom home file is the best for the application. I have lowered the feedrate to 500 mm/min for the reverse action to clear the switches. This is accurate enough.

Thanks