Won't HOME after capacitive sensor installed

[dc42]

@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-1

So 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.

[Excelon]

@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.

[Phaedrux]

@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-1

So 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.

[Excelon]

@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-1

So 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).

[Phaedrux]

@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.

[Excelon]

@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

[Phaedrux]

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 Z0.25 And 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?

[Excelon]

@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 Z0.25 And 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%)

[Phaedrux]

@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.

[Excelon]

@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?

[Phaedrux]

When you do G30 S-1 there will be a measurement reported in the gcode console. What value does it give you?

[Excelon]

@phaedrux said in Won't HOME after capacitive sensor installed:

When you do G30 S-1 there will be a measurement reported in the gcode console. What value does it give you?

I got it, I got it, I got it! I so sorry. That was an oversight on my part. I was totally over engineering it for sure.

I think the best issue is when I went ahead to test it by using G30 S-1 the nozzle height wouldn't change but when it prints it does indeed lower. So, basically I G92 Z0 when the nozzle is touching the bed and the raise and G30 S-1 and the enter that height that the sensor goes off at and there is your ( sensor trigger height to ' 0 '. Then when printing the first layer starts at 0.2 so Duet will now know where 0.2 is. DUH!!!

[Phaedrux]

Yeah I think you got it now.

So you take the result of G30 S-1 from the console, and put that in G31 Z.
Then if you still need to adjust the first layer with baby stepping you can use that value to fine tune the G31 Z value.