Won't HOME after capacitive sensor installed
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@phaedrux Thats the problem, though. entering a Z height in the G31 line like you mentioned doesn't have an effect.
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What value do you get when you measure it with g30 s-1?
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@phaedrux
Ok, Sorry. I think I get it now. Lowering the nozzle to the bed and tricking the software to think its higher, AND THEN registering zero when it’s at its lowest point and touching the bed. Now, when entering a negative Z value on line G31 will allow it to go beyond the -0- threshold and to the squish zone where I have been killing myself to get to? -
Well the measured value will likely be positive because the probe is above the nozzle and should trigger before the nozzle actually touches the bed. But then it should make z0 equal z0 and 0.2 equal 0.2.
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@phaedrux I get it and it should work but I must have something off somewhere because it works and the nozzle is close to the bed and where I would want it for printing but as soon as I start the print its too high again.
These are the steps I'm taking and the results:
- Homeall which is great now thanks to you.
- Home Z ; which brings the probe over the center of the bed (same as homeall) but doesn't bring it back.
- Once over the middle of the bed and the 5mm dive height specified I run the G30 S-1 and it bring the nozzle all the way down to the bed and Z is reading -0.37 in the Duet webserver status.
BUT.... - When I intioniate a print the lowest Z goes down to in the webserver status is 0.20 which is too high.0_1545932907319_config (3).g [0_1545932923234_homeall (2).g]
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@excelon said in Won't HOME after capacitive sensor installed:
Home Z ; which brings the probe over the center of the bed (same as homeall) but doesn't bring it back.
You mean you are doing home all, and then homez?
Once over the middle of the bed and the 5mm dive height specified
You mean you are sending G30 S-1 while it is 5mm above the bed, or when it's touching the bed?
When you do G30 S-1 there should be a result shown in the Gcode console. What does it say?
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@phaedrux I think I got it figured out, but I am not able to change the Z height in config.g on command 31 like you said.
Yes, I am doing homeall and then homez. When I hit homez there is no return, only dive height return. Homez jogs out over the middle of the bed and lowers the nozzle until the sensor goes off and then returns +5mm Z height and stays there. From there I try and send G30 S-1 command but the sensor is still active and I get an error message stating that the probe is already active or sensing ( sorry, not by the printer at the moment ) so it wont lower the nozzle lower without manually raising it first. Then I tried what you recommended in your post about tricking Duet (G92 Z10) and I can finally lower the nozzle all the way to the bed like you mentioned. Once on the bed I run G92 Z0 and that zeros out the Z status and I raise the nozzle to the correct printing postion and note the positive number in Z status and added that to command G31 in config.g BUT..... when I go to print the nozzle is not all the way down on the bed and I now have to use babystep +/- 0.05 to raise the nozzle. If i go back into config.g and add "1mm" to command G31.... still nothing. I was under the impression that the number specified in the G31 command in config.g, whether is be -/+, is supposed to offset the Z height.
To answer your question. Yes, I was sending G30 S-1 after homez and couldn't until I manually raised the nozzle because the sensor is closed at that time ( or open, depending on type of sensor ). After I do everything you advised me of... tricking Duet to be 10mm higher and moved the nozzle to the bed, run G92 Z0, raise the nozzle to printing height, gcode console read 0.48 and that's what I entered in command G31 in config.g, but again.... still nothing. Only difference is now the nozzle in slap on the bed surface.
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Ok, follow these steps exactly. It sounds like you're doing extra things that aren't needed.
Home all. Don't hit home z after. This will home all the axis and return to 0,0.
Use the axis jog buttons to move the probe to the center of the bed, and lower the z axis as low as it will go.
If the nozzle touches the bed, send G92 Z0.
If it doesn't quite touch the bed, send G92 Z10 and then jog it down until it does touch the bed, and then send G92 Z0.
Now send G30 S-1. The probe should raise up on its own and then lower again until the probe triggers.
The g-code console should give you a z probe trigger height. That number will be used in G31 Z in config.g
Do you still get 0.48?
If you repeat the steps to move the nozzle to touch the bed, send G92 Z0, and then G30 S-1 a few times in a row, do you get pretty close to the same result each time?
Are you running a G29 after this to map out the bed?
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@phaedrux said in Won't HOME after capacitive sensor installed:
Ok, follow these steps exactly. It sounds like you're doing extra things that aren't needed.
Home all. Don't hit home z after. This will home all the axis and return to 0,0.
Use the axis jog buttons to move the probe to the center of the bed, and lower the z axis as low as it will go.
If the nozzle touches the bed, send G92 Z0.
If it doesn't quite touch the bed, send G92 Z10 and then jog it down until it does touch the bed, and then send G92 Z0.
Now send G30 S-1. The probe should raise up on its own and then lower again until the probe triggers.
The g-code console should give you a z probe trigger height. That number will be used in G31 Z in config.g
Do you still get 0.48?
If you repeat the steps to move the nozzle to touch the bed, send G92 Z0, and then G30 S-1 a few times in a row, do you get pretty close to the same result each time?
Are you running a G29 after this to map out the bed?Yes, I was doing a whole lot of extra steps. I agree with you simple is better so I did exactly like you said and in that order. Same thing! Again, the nozzle is flat on the bed. Yes, I am running G29 bed comp tool, also. Here is something to note. When you told me not to raise the nozzle and run G30 S-1. I couldn't. It gave me the same error message.
it's saying that the probe is already triggered so I had to manually raise it and then run G30 S-1 and yes, still getting around the same .48. Here is the major thing I think is the problem but I don't know how to fix it. When I enter the offset numbers in config.g in G31 ( IE Z0.48 ) I don't see the offset while printing but I do see it while running G30 S-1. Every time I get to that point and I enter the offset, reboot the machine and run the G30 line with the Z offset ( IE Z0.48 ) and the nozzle lands so perfect I take a deep breath and say i've got it, but like I said when I start printing the nozzle is flat against the bed and forced to use baby steps to bring it up.
What gives....? I do appreate all your help and feedback. I am not the least bit upset, only trying to get to the bottom of it, here.
Eric
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Ok that's something of note. The error when you you try to do G30 S-1 shouldn't happen and I think it's preventing you from getting a proper trigger height measurement which may explain the poor first layer height when you start a print.
I'm not very familiar with capacitive sensors, so I'm not sure what would be causing an already triggered error at the start of a probing move. Perhaps @dc42 has an idea why that might be.
When you run G29, does it complete the mesh compensation map successfully or do you get errors there as well?
Can you post an image of the heightmap? I'm curious to see the result.
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@phaedrux said in Won't HOME after capacitive sensor installed:
I'm not very familiar with capacitive sensors, so I'm not sure what would be causing an already triggered error at the start of a probing move. Perhaps @dc42 has an idea why that might be.
That error is to be expected. The sequence was:
G30 S-1
G92 Z0
G30 S-1So the sensor wasn't raised before the second G30 S-1 was sent.
The way I recommend measuring the trigger height is at https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe?revisionid=HEAD#Section_Calibrate_the_Z_probe_trigger_height.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@phaedrux said in Won't HOME after capacitive sensor installed:
Ok that's something of note. The error when you you try to do G30 S-1 shouldn't happen and I think it's preventing you from getting a proper trigger height measurement which may explain the poor first layer height when you start a print.
I'm not very familiar with capacitive sensors, so I'm not sure what would be causing an already triggered error at the start of a probing move. Perhaps @dc42 has an idea why that might be.
When you run G29, does it complete the mesh compensation map successfully or do you get errors there as well?
Can you post an image of the heightmap? I'm curious to see the result.
I do understand that everyone is not familiar with all types of sensors and I do appreaciate all your help. I guess we are both learning as we go.
I always run the G29 mesh comp and it does always complete. Here are the results.
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@dc42 said in Won't HOME after capacitive sensor installed:
@phaedrux said in Won't HOME after capacitive sensor installed:
I'm not very familiar with capacitive sensors, so I'm not sure what would be causing an already triggered error at the start of a probing move. Perhaps @dc42 has an idea why that might be.
That error is to be expected. The sequence was:
G30 S-1
G92 Z0
G30 S-1So the sensor wasn't raised before the second G30 S-1 was sent.
The way I recommend measuring the trigger height is at https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe?revisionid=HEAD#Section_Calibrate_the_Z_probe_trigger_height.
Uhg. I forgot that G30 S-1 doesn't raise the probe to the dive height first. My apologies @Excelon for leading you astray.
Your heightmap doesn't look too bad really. It would appear that the bed just needs to be mechanically leveled with the adjustment screws to drop the rear right corner and raise the front left. Keep in mind that after making changes to the physical plane of the bed like that you'll need to regenerate the height map with a new G29.
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@phaedrux said in Won't HOME after capacitive sensor installed:
@dc42 said in Won't HOME after capacitive sensor installed:
@phaedrux said in Won't HOME after capacitive sensor installed:
I'm not very familiar with capacitive sensors, so I'm not sure what would be causing an already triggered error at the start of a probing move. Perhaps @dc42 has an idea why that might be.
That error is to be expected. The sequence was:
G30 S-1
G92 Z0
G30 S-1So the sensor wasn't raised before the second G30 S-1 was sent.
The way I recommend measuring the trigger height is at https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe?revisionid=HEAD#Section_Calibrate_the_Z_probe_trigger_height.
Uhg. I forgot that G30 S-1 doesn't raise the probe to the dive height first. My apologies @Excelon for leading you astray.
Your heightmap doesn't look too bad really. It would appear that the bed just needs to be mechanically leveled with the adjustment screws to drop the rear right corner and raise the front left. Keep in mind that after making changes to the physical plane of the bed like that you'll need to regenerate the height map with a new G29.
https://forum.duet3d.com/compose?p=/topic/8266/won-t-home-after-capacitive-sensor-installed/52#
Not to worry @Phaedrux . I apprecate all your help.I tried to manually level the bed and got it a little better so that's good in the right direction, but still not able to get the nozzle down close enough to the bed for proper printing ( I have to use Z baby stepping in "Job status ". I tried editing the G31 line like you mentioned in my config.g file, but... nothing happens. Now, moving the nozzle down with the baby stepping function is that big of a deal, but it just bit me in the arse because I forgot to lower the nozzle and realized that the Z baby stepping value is '0' by default upon reboot. Basically, I would have to remember to lower the nozzle via "Z baby stepping" every time the printer starts.
Other than that the upgrade is performing flawlessly and about to take on installing a Duet 2 wifi in my brand new Creality CR 10S Pro. Only thing that's held me back from installing so far is that the extruder heater cartridge, thermistor, both fans and X stepper motor are all wired directly to the current board via a ribbon cable. Each components wires go to a mini circuit board and probably share a common power (24v) rail (which is my guess).
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@excelon said in Won't HOME after capacitive sensor installed:
Basically, I would have to remember to lower the nozzle via "Z baby stepping" every time the printer starts.
You can take the amount of baby stepping used and add it to the G31 Z value to make it permanent. I do that myself to fine tune the z height.
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@phaedrux said in Won't HOME after capacitive sensor installed:
@excelon said in Won't HOME after capacitive sensor installed:
Basically, I would have to remember to lower the nozzle via "Z baby stepping" every time the printer starts.
You can take the amount of baby stepping used and add it to the G31 Z value to make it permanent. I do that myself to fine tune the z height.
Happy New to all!
That's what I'm trying to explain... no matter what value I add in the G31 command in config.g the nozzle doesn't change height. What's strange in that the offset is depicted in the machine status. Would you mind having another look and see maybe there is something I'm missing. Something small, maybe.
Also, would you mind posting your config.g and homeall.g so I can see what you have. If I see a different config.g that's functioning properly maybe that will give me some insight as to better program my rig.
I would like to get to the bottom of all this because I'm getting ready to install the second Duet board in my other printer and would love to get things ironed out.
Thank you
Eric1_1546363956637_config.g 0_1546363956637_homeall.g -
Your config and homeall look fine.
What exactly do you mean by "What's strange in that the offset is depicted in the machine status."
With your G31 like this,
G31 X-75 Y-45 P1000 Z0.25And you move the nozzle to Z0, does it touch the bed? How much baby stepping do you have to apply to get it to touch?Z0.25 seems like a low value for the trigger height, but I'm not familiar with capacitive probes, so maybe it's not. How do you have the probe mounted?
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@phaedrux said in Won't HOME after capacitive sensor installed:
Your config and homeall look fine.
What exactly do you mean by "What's strange in that the offset is depicted in the machine status."
With your G31 like this,
G31 X-75 Y-45 P1000 Z0.25And you move the nozzle to Z0, does it touch the bed? How much baby stepping do you have to apply to get it to touch?Z0.25 seems like a low value for the trigger height, but I'm not familiar with capacitive probes, so maybe it's not. How do you have the probe mounted?
Maybe we are talking about the wrong thing in general and we are both off topic. I don't know so I would like to clarify just to make sure.
I am trying to physically get the nozzle lower to the bed and also the ability to manually change nozzle height for different filaments and bed temperatures because capacitive sensors vary widely due to temperature. I manually installed the sensor which is about 7mm higher than the nozzle but the sensor doesn't touch the bed when its activated. I set the sensor so the nozzle stops 1.5mm to 2.0mm away from the bed. When I follow the steps you and dc42 instructed me to do the software changes but NOT the nozzle height. Even after I bring the nozzle to the bed, set it to zero ( G92 Z0 ), raise it to printing height and take that value ( which is right around 0.25mm ) and enter it in G31 line in config.g my nozzle height doesnt change.
Is there a better system for bed leveling that works a bit easier with duet or am I just having a slight hiccup on this? H
Here is a picture of the sensor
[0_1546368763656_20190101_134454.jpg](Uploading 45%)
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@excelon said in Won't HOME after capacitive sensor installed:
I set the sensor so the nozzle stops 1.5mm to 2.0mm away from the bed.
Then your G31 Z value should be 1.5 to 2.0mm. The whole G30 S-1 procedure is trying to measure how far your nozzle is away from the bed when the probe triggers. Where do you get 0.25 from? and How did you get 1.5 to 2.0mm?
Even after I bring the nozzle to the bed, set it to zero ( G92 Z0 ), raise it to printing height and take that value ( which is right around 0.25mm ) and enter it in G31 line in config.g my nozzle height doesnt change.
That's not what you should be doing at all.
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@phaedrux said in Won't HOME after capacitive sensor installed:
@excelon said in Won't HOME after capacitive sensor installed:
I set the sensor so the nozzle stops 1.5mm to 2.0mm away from the bed.
Then your G31 Z value should be 1.5 to 2.0mm. The whole G30 S-1 procedure is trying to measure how far your nozzle is away from the bed when the probe triggers. Where do you get 0.25 from? and How did you get 1.5 to 2.0mm?
Even after I bring the nozzle to the bed, set it to zero ( G92 Z0 ), raise it to printing height and take that value ( which is right around 0.25mm ) and enter it in G31 line in config.g my nozzle height doesnt change.
That's not what you should be doing at all.
Ahhh. OK, I was setting the nozzle on the bed, zeroing and then whatever the distance from that point to printing height is what I entered for G31. So, you're saying I need to measure the distance from where ever G30 S-1 puts the nozzle to printing height and not from nozzle touching the bed?
