Auto-leveling issues; PINDA probe needs replacing?
 
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bruce.g
(@bruce-g)
Active Member
Auto-leveling issues; PINDA probe needs replacing?

Having some problems with my Prusa, hopefully someone can confirm my suspicions (or point me to something else if they're wrong 🙂 ). I believe it's an issue with the PINDA probe based on things I've read here and elsewhere, but I want to be sure, and I have a few other questions.

Recently I started getting the error "Bed leveling failed. Sensor didn’t trigger. Debris on nozzle? Waiting for reset." when the printer was working through the auto-leveling sequence prior to a print (note that there was no debris on the nozzle - either the hot end nor the black part of the probe). I noticed that at times the red LED on the PINDA probe was off when it shouldn't be or it was flickering. Eventually I found that I could get it to stay on if I moved the wire harness around a bit. I also opened the RAMBO box to check the connector for the probe; it seemed like it was loose so I removed it and plugged it back in. Closed the box and things started working properly again, though only for a print or two.

Now, generally from what I can see the LED on the probe is on when it should be (and it turns off when I put my metal removal tool under it), but when the auto-leveling starts, the first point is fine, then the extruder raises up, goes to the second point, doesn't even try to calibrate, and I get the failed error message again. At this point the probe is also around 31/32mm above the bed. The LED is on, and when I try to move the extruder via "Move Z" in Settings, it won't go down as it's showing me that I'm at 000.0 for Z.

It seems to work now if I go into "Calibration", do "AutoHome", then "Selftest" and then choose something to print. However, I've noticed a couple things when I've done this. First, when something does print, in the past after the auto-leveling calibration it would lay down a strip of filament from calibration point 1 up to two or so, and then move to the starting point on the print bed. It still goes through this motion, but there's only about half the filament on the bed than was usual in the past. I also saw this on the bottom of my last print:

(See bottom of post; I couldn't get the "img" tag to work...)

I'm assuming that what I see should be more uniform than that.

So, my assumption is that something is wrong with the probe, either the wire or the probe itself. It also seems like even though it goes through auto-leveling after the autohome/selftest, it's not working correctly. First question - does that seem like the correct assumption or is there likely a different culprit? My other questions:

- Can you still order replacement probes from Prusa? I can't find them anywhere on the website.

- If you can't, where's the best place to find them? Can I get one that already has the connector for the RAMBO board or do I need to solder that on myself? Can I just splice in a new wire between the probe and the connector, or is that unlikely to fix the issue? (OK, that's three questions 🙂 )

- Once I replace the probe, will I need to run through XYZ calibration again? I'm also assuming I'll at least need to tweak my Live-Z again.

I've been planning on getting the MK2.5 upgrade kit (which includes a probe replacement), but I'd like to still be able to print until it gets here (the website says they're available in July). I'd also need a working printer so I can print the new plastic components.

Sorry for the long post, and thanks in advance for any advice you can give me!

Posted : 01/06/2018 3:55 am
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Auto-leveling issues; PINDA probe needs replacing?

it is likely that one of the Pinda wires has fatigued due to constant flexing,

what I did was to replace the wire between the X axis carriage and the Rambo box, making sure to use heat shrink tubing to insulate the wires

the joints were made in sections of the cable which don't flex

this will keep you going until your upgrade arrives! 🙂

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 01/06/2018 10:39 am
bruce.g
(@bruce-g)
Active Member
Topic starter answered:
Re: Auto-leveling issues; PINDA probe needs replacing?

Joan - Thanks! I'll give that a shot 🙂

Posted : 02/06/2018 7:28 am
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