BLTouch getting triggered
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I have an original bltouch which is working fine. Here's my homez for reference:
[[language]] ; homez.g ; called to home the Z axis ; M561 ;reset bed compensation T0 ;select tool G91 ;relative coordinates M280 P3 S160 I1 ;release Z probe alarm G1 Z5 F2000 ;lower bed G4 P500 ;wait for the bed to lower G90 ;absolute positioning G1 X145 Y145 F3000 ;move to center M401 ;deploy the probe G30 ;calibrate Z-axis M402 ;Retract ProbeAnd the endstop part of config.g:
[[language]] ; Endstops M574 X2 Y1 S1 ; Set active high endstops M574 Z1 S2 ; Set endstops controlled by probe M307 H3 A-1 C-1 D-1 ; bltouch M558 P5 X0 Y0 Z1 H3 F250 T3000 ; bltouch G31 X-25 Y20 Z2.8 P25 ; bltouch offset M557 X15:265 Y25:275 S80 ; Define mesh grid -
okay..so i fixed the mean error. now this is my current, i placed a debug mode on the config.g as it is weird it stops at the same place all the time.
still i am able to home with 3 of 5 the probe not alarming.[[language]] confg.g M667 S1 ; Select CoreXY mode M208 X0 Y0 Z0 S1 ; Set axis minima M208 X300 Y285 Z300 S0 ; Set axis maxima ; Endstops M574 Z0 S2 ; Set active low endstops (z end stop disabled) M574 X1 Y1 S1 ; Set active high endstops M558 P5 X0 Y0 Z1 H7 F100 T3000 ;debug mode G31 X25 Y0 Z3.31 P30 ;debug mode ;M558 P5 X0 Y0 Z1 H10 F100 T4000 ; Set Z probe type to unmodulated, the axes for which it is used and the dive height + speeds BLTOUCH ;G31 P5 X0 Y0 Z5 ; Set Z probe trigger value, offset and trigger height BLTOUCH M557 X0:300 Y0:285 S50 ; Define mesh grid[[language]] bed.g M561 ; clear any bed transform ; Probe the bed at 4 points G30 P0 X10 Y0 H0 Z-99999 G30 P1 X10 Y265 H0 Z-99999 G30 P2 X275 Y265 H0 Z-99999 G30 P3 X275 Y0 H0 Z-99999 G30 P4 X145 Y135 H0 Z-99999 S[[language]] ; homeall.g ; called to home all axes ; ; generated by RepRapFirmware Configuration Tool on Wed Dec 27 2017 18:31:34 GMT+0800 (PHT) G91 ; relative positioning G1 Z7 F800 ; lift Z relative to current position M280 P3 S160 I1 ; Clear any alarm G1 S1 X-305 Y-305 F1800 ; move quickly to X or Y endstop and stop there (first pass) G1 S1 X-305 ; home X axis G1 S1 Y-305 ; home Y axis G1 X5 Y5 F360000 ; go back a few mm G1 S1 X-305 F360 ; move slowly to X axis endstop once more (second pass) G1 S1 Y-305 ; then move slowly to Y axis endstop G90 ; absolute positioning G1 X10 Y0 F360000 ; go to first bed probe point and home Z G30 ; home Z by probing the bedwas able to have this deviation after placing the bed, then i tried to relevel the bed then i cannot get to mesh completely as it is stopping at the same point.
[[language]] RepRapFirmware height map file v2 generated at 2018-01-06 20:56, mean error 0.248, deviation 0.204 xmin,xmax,ymin,ymax,radius,xspacing,yspacing,xnum,ynum 10.00,290.00,0.00,270.00,-1.00,108.80,108.80,3,3 0.029, 0.200, 0.093 0.010, 0.435, 0.245 0.110, 0.541, 0.572 -
when it reached that spot on the bed the probe triggers an alarm..which is super weird.
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my bed is warped lightly on the middle, is that why i cant do a correct calibration?
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able to do a 9pt mesh compensation, is there a limit to the compensation?
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ended up doing a 4pt as the middle of the bed is stopping the probing.
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Try increasing the Z dive height parameter, that's H in the M558 command.
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i'll try with a flat glass to see if it changes, as it might be detecting a super dent or something.
so far right now i think all is good with the 4pt. -
i noticed that when i hit print another on DWC it does not do the full cycle from homing to g29 S1, it just starts to print right away.
so what i do is after printing i hit the print button on gcode files to print another one. -
it seems no matter how much dive i do if the bed itself is very warped/distorted the probe will detect the irregularity.
i added glass to the bed and its all better now. able to do a 9pt-25pt on the bed.Thanks All!
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Hi @pao_wikhan
Did you fix the error with probe triggering at very high position? I seem to be having very similar issue. My probe just triggers without even touching the bed.
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@zen
yep. im using 1.20 firmware and i used p8 on the m558. -
It didn't help in my case. This entire thing is driving me crazy, it behaves randomly
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@zen said in BLTouch getting triggered:
It didn't help in my case. This entire thing is driving me crazy, it behaves randomly
To use bltouch we recommend firmware 1.21 (or 2.0beta) and P9 in M558.
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 -
@dc42 Yeah, exactly what I'm using. Essentially I tried everything I could.
Is it even possible that Duet is not providing enough amps on 5v rail? BLtouch is like 300mA, so I guess we should be ok here.
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I had a similar situation where the BLTouch would often trigger early. The reason turned out to be that the pin inside the housing was dirty from the factory. There was some sticky residue that would keep it from dropping. The solution in my case was to remove the small set screw at the top of the housing to remove the pin. I then used fine grit sand paper and 99% alcohol and water to clean the pin and the opening of the housing. After reassembly it functioned perfectly.
Even if it's not dirty, you may need to adjust the set screw to adjust the sensitivity, since it's the set screw that acts as the magnetic core to draw up the pin. A half turn one way or the other may be enough to get it tuned properly.
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@phaedrux I just disassembled it today, but since I haven't seen any dirt, I didn't clear it. Also I read that grub screw should be exactly 0.3mm from flange. I will set it like this tomorrow and check results.
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If the bltouch triggers the moment it is deployed due to the pin not dropping fast enough, adding some Z probe recovery delay should help. It's the R parameter in the M558 command. The units are seconds, so try e.g. R0.2. Alternatively, add a G4 delay command at the end of deployprobe.g.
