Servo deployed probe on Duet Maestro
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Hi, I'm trying to understand how I can configure/wire a servo deployed probe on my Maestro. It's a basic micro-switch and the servo to deploy it is a emax es08ma ii
I believe this should be possible through the Z probe connection. The servo is 5v from what I can tell. So wire that to 5v and GND with the trigger to zprobe.mod. The switch is 3.3v. Can I use the 3.3v on the Z probe connection? I then connect the other wire to Z probe in?
If this is correct then I'm running RRF3.2
I'm not sure how I configure this in my config.g. It's similar to a BLTouch I guess but should I be thinking differently?
Thanks
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It should be pretty similar to the BLtouch. You have a servo to deploy and retract and a switch to trigger.
As for exactly what goes where I'm not sure. But if you have the pinouts from your servo and switch and can make analogies to the BLtouch you should be able to work it out?
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@Phaedrux I'm working the pinouts out although I don't see that as the problem as such. I guess what I'm asking is for confirmation of the gcode I should be using to make this work. I'm working hard to get my head around it all. Keen to learn.
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Well the config portion would be very similar to the bltouch. You'd need to define the servo pin with an M950 and you can use the deployprobe/retractprobe macros to control it with servo movement commands. It'll depend on your servo what those commands are. And your M558 trigger pin would need to be defined.
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Thanks for the info. I connected the servo up to the board and was trying to use the command line to send gcode to try test it but I've figured I have to connect everything up and then work through the gcode to get it to do what I want. I was trying to test but I think I've oversimplified thinks in my own mind.
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Here's an alternate probe kind of like the BLtouch that might open your mind to thinking about how it might work for yours.
https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Touch_Mi
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Thanks. I hope to get to a position over the weekend to be able to test everything. This will be useful.
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Post some photos/diagram of your intended wiring and you might get some feedback.
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@Phaedrux I'll add some in the morning before I look to test/proceed. Thanks for the advice.
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i am using this
https://www.thingiverse.com/thing:3303618
and it works on the maestro.
all the connections are going to the z probe header.
gnd is combined and 5v is combined in this case.
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Thanks all. @Veti how did you define that probe in your config?
I plan to try get this working tomorrow
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M574 Z1 S2 ; Set endstops controlled by probe
M950 S0 C"^zprobe.mod" ; create servo pin 0 for BLTouch
M558 P8 C"^zprobe.in" H2 F900 T6000 ; Set Z probe type to switch and the dive height + speeds
G31 P1000 X31 Y-8 Z2.43 ; Set Z probe trigger value, offset and trigger height -
Thanks. I’ll need to work through each command but it’s very helpful having a reference. Appreciate your help
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I've tried to get this to work today. I think the servo may have broken though. I initially was able to get the servo to deploy the probe but the M402 retract command did it not M401 so I figured my deploy and retract settings were obviously wrong. Neither command does anything now.
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Smaller servos can burn out if forced in a way they can't go.
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@Phaedrux That's likely what has happened. I plan to take it out later. I've ordered a new one in case it has. I'll test it out of the printer.
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I've replaced the servo and the probe now deploys. It seems to work fine when I issue M401 and it retracts to M402.
In the dashboard my probe is showing as 1000. I'm a bit lost with this part. I've defined it as a switch with P8.
The nipple microswitch (for want of a better description) I'm currently using has two wires, so different to a microswitch I'm used to where there are 3 connection points. It's a Zippy switch. I'm trying to work out the two wires which at the moment I have one connected to the 3.3v on the zprobe header and the other to the zprobe.in.
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And what do you have in your M558 line? It may need to be inverted.
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@Phaedrux This is what I currently have.
M950 S0 C"^zprobe.mod" ; create servo pin 0 for BLTouch M558 P8 C"^zprobe.in" H5 F120 T6000 ; Set Z probe type to switch and the dive height + speeds G31 P1000 X-20 Y-10 Z15 ; Set Z probe trigger value, offset and trigger height -
Try this
M558 P8 C"^!zprobe.in" H5 F120 T6000
G31 P500 X-20 Y-10 Z15
