Reduce the P value in your G31 statement so that it is closer to the resting z-probe value (491).
You may need to experiment with how tight the four assembly screws are, if they're too tight the probe will be less sensitive.
To avoid false triggers reduce acceleration and jerk during probing.
Idris
For physically levelling the bed I find it useful to probe only five points, the four corners and the centre.
The pattern you are seeing there may be the result of the bed moving different amounts at different points when the nozzle touches it, The best way to improve that is to increase the sensitivity of the Orion.
Idris
You might need to add some foam under the piezo to improve damping.
If the wires from the piezo disks to the Universal controller are long or are routed next to heater or stepper cables you may be getting interference.
Finally, with the mass of the bed providing inertia, you need to do everything you can to reduce the impulse when you start homing, even though your bed is not moving. Reduce instantaneous speed change for Z to zero, at least during probing. Reducing Z acceleration will also help. This should allow you to set the trigger threshold closer to the resting value without getting spurious triggers, improving accuracy.
Idris
You've plugged your 3pin cable into the analog output of the board. You either need to move the cable to the digital pins next to the D or use the P1 mode and set up for analog triggering.
Idris
G28 simply calls the relevant macro home(x).g , all the actual homing is handled in the macro.
G32 calls the bed.g macro if it's present.
Idris
The Orion does not output a voltage, all it can do is pull down the SIG pin to GND.
During testing, the only time any part of the Orion got hot was if the three pin cable was plugged in the wrong way 'round, is it possible this happened to you?
DC42, is the 3v3 supply to the Z-probe connector on the Duet short circuit protected?
Idris
That's one option, I guess I was looking for something a bit more elegant. I'll look at the thermistor on the driver idea.
Idris
Is there a way to have a fan turn on whenever the steppers are turned on but turn off whenever the steppers are turned off?
I've just put my Duet in a case with a fan on the back side, my printer stays on permanently but most of the time it's idling and so doesn't need the fan running. I'm just wondering whether there's a way to automate switching it off and on?
Idris
Is that a recent firmware feature?
Idris
You need to specify the value of the series resistor in order to get accurate readings
M305 P1 X501 R4700 ; Specifies a 4.7k resistor for the Duet Wifi
M305 P1 X501 R2200 ; Specifies a 2.2k resistor for the Duet Maestro
Idris
The output of the Orion is active low.
Paul and I went through all the trouble shooting steps I could think of last night. He measured voltages of 3.233 untriggered and 0v triggered. This is at the Orion end of the cable, however, since the Orion uses an open drain output, a broken cable would result in a floating pin that normally measures ~0.5v. He also tried with three different cables.
What's really puzzling to me is what's shown in the video, the Orion triggers lighting the blue LED but the bed keeps moving. If there were an issue with the sensitivity of the Orion or its triggering then I would expect to see the bed hit the nozzle, keep moving, and then have the Orion trigger. It appears that the Duets response to the trigger signal is delayed for some reason.
Idris
Can you post your M558 line? You should be using P8 with a threshold of 500, the signal range is between 0 and 1000.
Can you tune the Uni v2.75 so that the blue led is lit and then see what the reported value is?
Idris
@interwebsdesigner You need to include an I1 (i1) in your M558 line, the V2.75 uses an active low signal, I1 inverts the signal for the duet.
Idris
If the problem follows the effector then it suggests that the issue is something downstream (closer to the nozzle) than the effector/rod interface. Looking at your picture it the effector appears somewhat thin, depending on your infill and particularly the number of top and bottom layers it's possible that one corner is slightly more or less flexible.
Definitely try backing off the assembly screws a bit.
Idris
There are a couple of things that could be causing the issue that you're seeing but they all come down to one thing, something is different about the left side of your printer compared to the right. It could be that the belts have slightly different tensions. Or that the infill pattern of your effector makes one side stiffer than another or something else like that.
My suggestions for trouble shooting would be to move things around and see whether the problem also moves. For example you could turn the effector by 120deg and see whether the affected area of the bed also moves.
I also notice that in a couple of places the probe triggers as soon as it starts to move, are you using a delay before probing? I'm concerned that the inertial of all the parts that you have hanging off the heatsink may be causing problems, ideally all the fans would be mounted to the effector, not the heatsink.
Idris
Just a heads up: I wont be dispatching anything between 21/12/18 and 3/1/19
Idris
@rikesh942018 I've just uploaded the step file to thingiverse, follow the link above.
Idris
No, this is not the Andromeda board, this board has not yet been released.
Idris
I think that you would be able to print a mount in nylon or some other material that would hold up in a heated chamber up to the temperature where the piezos would become unreliable anyway (somewhere around 80c I would expect)
Idris
Yes, it's actually very secure even when tightened by hand.