BLTouch Self-Triggering during multipoint probing
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I had the same problem. Turned out it was EMI. or RF noise. I switched from a T/c to a thermistor and the problem never reoccured.
Too bad the mesh compensation turned out to be such a total waste of time. It works better just to tweak the leveling knobs and just chuck the unnecessary complexity. -
@andy-cohen That's odd, even with my probe issues I'm having FANTASTIC results with triple Z mesh compensation. I did design my Z positions so they intersect exactly at the corners of the bed though, not sure how much of a difference that makes.
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@andy-cohen said in BLTouch Self-Triggering during multipoint probing:
Too bad the mesh compensation turned out to be such a total waste of time. It works better just to tweak the leveling knobs and just chuck the unnecessary complexity.
Have to agree, I am thinking of getting rid of the BL Touch and going back to Mesh Bed Levelling and tweaking on the skirt.
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I wonder if i'm having the same issue or not.
From the beginning the probe triggers immediately after releasing, its like the pin is "jumping".
So it's released.. going down.. immediately triggered... going up again... getting released again without any delay (doesnt matter how you set R).
This happens few times, is accepted from the duet and then probing goes on with the next point.The result looks like
means that I have to retry until its finally working on all points.
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If you are probing with the bed heater on, try it with the bed heater off, or add the B1 parameter to the M558 command in config.g. The BlTouch is sensitive to magnetic fields and some DC bed heaters in particular generate them. Also check the crimp connection on the white wire from BLTouch where it connects to the Duet.
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Im proding without heater amd with B1 from the start.
From some further testing I can say that the "M280 P7 S10 I1" is already triggering that effect... sometimes filing that command is causing it to jumpo couple of times.
Maybe its possible to add a "max value" to the M558 similar to the S on M671.
As the wrong triggering values are usually waaay up like 8+mm compared to correct values which might be < 2mm.
It would help sent an upper max limit on the M558.
Besides that, it feels like the A on M558 has an upper limit? Can this be increased as well? cause that seem to help with that issue. Seems like A50 doesnt work ... A10/15 do but depending on self-triggering 10 is easily reached sometimes. -
When it triggers prematurely, does the pin definitely extend all the way first? If it doesn't, perhaps the pin is sticking.
Are you using the M558 R parameter to insert a small delay before probing?
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The Pin is going fully down and then up again.
I tried with different R values, from 0 to 1 without any effect.
I also tried a G4 P500 in retract and deploy .g files before and after the M280 without any effect either - besides the sensing failing completely.Im using these two
retractprobe.g
M280 P7 S90 I1 ; Send PWM channel 7 the S90 (angle) commanddeployprobe.g
M280 P7 S10 I1 ; Send PWM channel 7 the S10 (angle) commandThe "jumping" occurs simply with just the "M280 P7 S10 I1" command. Its more bother me that the firmware is accepting these off value as valid.
Thats the issue:
https://youtu.be/nKLlnVU03I4Im only doing pin down and pin up, over and over again, jumping happens all alone...
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@nightreaver said in BLTouch Self-Triggering during multipoint probing:
The "jumping" occurs simply with just the "M280 P7 S10 I1" command. Its more bother me that the firmware is accepting these off value as valid.
I'm not a bltouch expert, but to me that suggests a problem with the bltouch.
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@nightreaver Replace the knockoff clone with an actual BLTouch. You'll have much better luck.
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@andy-cohen said in BLTouch Self-Triggering during multipoint probing:
Too bad the mesh compensation turned out to be such a total waste of time.
It works very well for me and allows me to easily print a perfect first layer on my entire 300x300mm bed. I wonder what problems you encounter.
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@dc42 Can you confirm that M558 A has upper limit? When I set it to 15 with works okay, when I set it to 50 it seems like the limit goes down to A2 or something. Is this right?
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@nightreaver said in BLTouch Self-Triggering during multipoint probing:
@dc42 Can you confirm that M558 A has upper limit? When I set it to 15 with works okay, when I set it to 50 it seems like the limit goes down to A2 or something. Is this right?
From the Bug Fixes section of the firmware 2.03 release notes at https://github.com/dc42/RepRapFirmware/blob/dev/WHATS_NEW.md:
Setting M558 A parameter to anything >31 set it to 0 instead of to 31
