Bl-touch re-deploy after probing or z homing

bugm

Hi
I installed a Bl-touch clone and something wired happening.
All seems to be fine when running the deploy, retract and self test macros.
however when i home Z-axis or doing a mesh bed compensation - something wired happens:
1 The probe goes to the requested coordinates
2 deploy the pin
3 the bed goes up toward the bl-touch sensor.
4 after the pin tuoch the bed its auto retract.
5 the bed starts going down
until now all is just fine..

After it probed the point - while the bed goes down away from
the probe - the pin suddenly deployed again, hits the bed very fast and retracts.
this can happen randomly, about 20% of the probed points and
it effecting the bed mesh as red area that appears on the mesh map.
All suggestions are welcomed

p.s i am running the latest duetwifi 2 fw on corexy printer

dc42

Update the firmware to 2.01 or 2.02RC2.

BLV

so i am not the only one who is getting this behavior
same situation here, it deploys randomly right after probing with the 2.02rc2
on sunday i'll get my bud touch sensor just to make sure its not a bad one.
cables are fine, no shorts or disconnection.
thought about adding some delay or fast dropping the bed before it will bump it.

tjb1

I had this same issue with a BLTouch from TriangleLab. It would deploy, touch the bed, retract, and then shoot back out and retract again. It also fell down in the middle of the print several times causing it to keep catching on the print and if it didn't fall all the way it would error out. I tried rewiring it (including pulling the wires away from the stepper/heater wires) and even mode 9 with no success. I don't know if it's because it's a clone or not but I took it off and switched to piezo.

dc42

This behaviour was common when using earlier firmwares, but only caused a problem if the Z travel speed of the probe after triggering was low. It was fixed in firmware 2.01. See https://github.com/dc42/RepRapFirmware/blob/dev/WHATS_NEW.md.

tjb1

Would this include it randomly falling in the middle of a print or is that a different issue?

genghisnico13

@tjb1 Perhaps you could try unscrewing the top screw (core) a little, I never experienced that issue, but maybe this helps.

dc42

@tjb1 said in Bl-touch re-deploy after probing or z homing:

Would this include it randomly falling in the middle of a print or is that a different issue?

No, that would be a different issue.

BLV

@genghisnico13 said in Bl-touch re-deploy after probing or z homing:

@tjb1 Perhaps you could try unscrewing the top screw (core) a little, I never experienced that issue, but maybe this helps.

yesterday i cleaned, magnetized and replaced the heatshrink but its still deploying randomly .

bugm

@dc42 said in Bl-touch re-deploy after probing or z homing:

This behaviour was common when using earlier firmwares, but only caused a problem if the Z travel speed of the probe after triggering was low. It was fixed in firmware 2.01. See https://github.com/dc42/RepRapFirmware/blob/dev/WHATS_NEW.md.

I am running the latest 2.02RC2 version

@blv said in Bl-touch re-deploy after probing or z homing:

@genghisnico13 said in Bl-touch re-deploy after probing or z homing:

@tjb1 Perhaps you could try unscrewing the top screw (core) a little, I never experienced that issue, but maybe this helps.

yesterday i cleaned, magnetized and replaced the heatshrink but its still deploying randomly .

thanks,this morning i bought a shrink and replaced it too and yet it still doing it.
its functioning flawlessly in test mode but while probing its still deploying twice.

dc42

Please run M558 and check that it reports you are using Z probe mode 9.

bugm

@dc42 said in Bl-touch re-deploy after probing or z homing:

Please run M558 and check that it reports you are using Z probe mode 9.

Thank you, it look s like it is on mode 9. maybe i need to try mode 5?

edit: when trying mode 5 the pin deploy agian (twice) instead of once but the second deploy is with a 1 sec delay.

BLV

@dc42 said in Bl-touch re-deploy after probing or z homing:

Please run M558 and check that it reports you are using Z probe mode 9.

I can confirm that my friend's bltouch is acting same. even changed the wiring and its beeing deployed twice - at neer 30% of the probing points.
2.02rc2 on mode 9 too.

dc42

Is this on a Duet WiFi, Ethernet, or Maestro?

BLV

Mine is a DuetWifi 2 v1.01
today i played with all the M558 parameters but nothing changed this wired behavior.
the Bltouch is a clone with 3.3v output (trace has been cut)

Phaedrux

I think it being a clone has more to do with it than anything.

Have you verified the trace is cut with a multimeter?

BLV

@phaedrux said in Bl-touch re-deploy after probing or z homing:

I think it being a clone has more to do with it than anything.

Have you verified the trace is cut with a multimeter?

I dont think so, because yeataday i installed my friend's genuine Bltouch v2.0 smart and it has the same problem.
Yes, i used a microscope at work to cut the trace and verified with a fluke.

Phaedrux

@blv sorry I missed that.

What are using for M558?
What are your movement speed settings?

BLV

@phaedrux
M307 H3 A-1 C-1 D-1
M558 P9 H5 F100 T6000

bugm

@dc42 said in Bl-touch re-deploy after probing or z homing:

Is this on a Duet WiFi, Ethernet, or Maestro?

i got the 1.01 - i erased the firmware and installed again 2.02RC2 from scratch - no difference.
no idea what to do, replacing the wires made no difference.
even while homing z axis alone, every 2-3 homing it keeps happening - after probing the pin deploys
again while the bed moving down (core xy). it hits the glass before the bed went down, then retracts.
just to check as @Blv - i installed it on my mks gen-l and it works without any issue.

genghisnico13

I've been having some problems with my 3D Touch (when it probes a hot bed), so I made a video to ask for a new one, is your probe behaving different from how its seen in the video?
Sorry for the background noise around the middle, the power company is making some holes.

Phaedrux

@genghisnico13 How do you have the probe mounted? Your video makes it look like there is a bolt right above the top of the probe and it looks like it might be right beside a stepper motor? It uses an electromagnet and could be susceptible to pieces of metal being too close to it. If you take the probe out of the mount and just suspend it in the air and trigger it by hand, does it behave the same way?

BLV

@genghisnico13 said in Bl-touch re-deploy after probing or z homing:

I've been having some problems with my 3D Touch (when it probes a hot bed), so I made a video to ask for a new one, is your probe behaving different from how its seen in the video?
Sorry for the background noise around the middle, the power company is making some holes.

Its almost identical, except that in my case its deploying the pin only one time after it already probed the point. (On your video its deploying even more).

genghisnico13

@phaedrux You could be right, but since the seller has already agreed to send me a new one.... I'll test it in mid air when the new one arrives (couple of months). Worst case I end up with 2 working probes.
I assumed it was designed to be in close proximity to ferrous materials and put it in the only place with free space that doesn't limit movement length, could have been a bad choice, will see after testing.

dc42

It's also worth remembering that high-current bed heaters can affect the trigger height of a BLTouch, although I've not heard of them causing the pin to redeploy. So if you are probing with the bed heater turned on, try turning it off, or add parameter B0 to the M558 command.