How long are the wires from the piezo disk to the piezo PCB? I can't see where you have the board mounted.
You also need to include a delay into the probe routine ( include R0.5 in your M558). This makes the printer wait for half a second between XY movements and Z probe movments to allow vibration to die down. Also, you should probably use the P8 mode rather than the P1, the output of the piezo PCB is digital, using P1 (analogue) only increases the chances of false triggers.
Idris
How does the firmware handle acceleration and jerk when the Z-probe is triggered?
In order to get smooth movement from my Z-axis (moving bed) I've set very low Z acceleration and 0 jerk during probing. When the Z-probe is triggered, does the firmware attempt to instantly stop the axis or does it adhere to jerk and acceleration settings?
This is primarily of interest to me because piezo probes have essentially zero overrun ability when compared to most other tech so it's important to stop the bed as quickly as possible. How much work would be involved with allowing for different acceleration and deceleration rates during Z-probe movements?
Idris
I'm somewhat surprised that it's working well with so much additional weight hanging off the hotend, I'd want to mount anything I could from the carriage rather than the Orion.
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
The "bow" in your bed may be caused by deflection of the bed when the contact point is far from the Z axis screws. This is something I've seen on my TronXY X5s, it was greatly improved when I changed the plastic Z bearing mounts to metal ones but I haven't been able to eliminate it completely yet.
Idris (Precision Piezo)
@hevilp I'm developing a board similar to the Orion that might be more suitable for the kind of vertical orientation you're talking about. It's currently being tested, if you want to cancel your Orion order just contact me through the store.
Idris
I found that the easiest way to check whether the bed was bowed or flexing about the leadscrews was to remove the plate and rotate it 90 degrees. If your readings now show a bow in the other direction then the bed itself is bowed, if the bow still appears to be in the same direction then the bed itself is moving.
Idris
@toskium I've replied to your email, I'll send you a replacement PCB today.
Idris
To reset the v0.6 to factory settings, turn VR1 and VR2 so that the flat part of the adjuster is closets to the bottom of the PCB.
You CAN use P1 but it has no advantage over P5 or P8 and may have some disadvantages. The output of the PCB is either 0v (roughly) or 3.3v (again roughly, later boards are better at this, they go closer to 0v but for this explanation assume 0v). The duet reads these values as either 1000 or 0. Because the output is digital, the value is either 1000 or 0 but nothing else inbetween. So the threshold makes no difference except that noise or interference on the signal wire might cause a false trigger.
David might be able to give more detail about how the firmware processes P1 and P5/8 differently.
TLDR: use P8
Idris
Either way, there are no physical stops.
Idris
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