suddenly no more printing  

Re: suddenly no more printing

Hi Florian,

do the axes all home properly?
often one of the axes gets a bit stiff and causes this issue, maybe add some lube,,,

if the LED on, on the Pinda when the pinda is not near the buildplate? does it go off when you put metal against the end of the PINDA?

regards Joan

Re: suddenly no more printing

Might be worth running the setup wizard if you have played with firmware. Go to the LCD menu, find calibration and run 'wizard'. Follow the prompts, this may or may not succeed, but it will tell you why it fails if it does.

See here also >

Re: suddenly no more printing

do the axes all home properly?
often one of the axes gets a bit stiff and causes this issue, maybe add some lube,,,

they all home propely, and I did lube them, even tho they don't seem to be stiff at all.

if the LED on, on the Pinda when the pinda is not near the buildplate? does it go off when you put metal against the end of the PINDA?

the led is on, and and goes off when i put metal under it.

Might be worth running the setup wizard if you have played with firmware. Go to the LCD menu, find calibration and run 'wizard'. Follow the prompts, this may or may not succeed, but it will tell you why it fails if it does.

See here also >

i ran the wizard but it does not finish. it runs the selfcheck properly and then homes, when calibrating z it stops and says I should check axes.

Re: suddenly no more printing

Then one of your Z axis steppers probably isn't moving - can you rotate the threaded rods with your fingers - it shouldn't take much force, they should feel the same. If you can do this and they are the same check the connections on the controller board.

Go here if you need to see where things fit - https://manual.prusa3d.com/Guide/8.+Electronics+assembly+(B7-R3+design)/823?lang=en

Re: suddenly no more printing

Then one of your Z axis steppers probably isn't moving - can you rotate the threaded rods with your fingers - it shouldn't take much force, they should feel the same. If you can do this and they are the same check the connections on the controller board.

Go here if you need to see where things fit - https://manual.prusa3d.com/Guide/8.+Electronics+assembly+(B7-R3+design)/823?lang=en

good advice and if you were a bit tired or you had misplaced your glasses the E on the extruder connector might have looked like a Z and so those connectors could have been mixed up. when I built my Delta I used hand written tags on everything I found I had swapped one of the tower connections with that of the extruder.... felt rather dumb... but it did get me to change from +1 reading glasses to +2.... I should have wondered why I was reading the newspaper with my arms fully extended...
Cheers
R

Re: suddenly no more printing

Then one of your Z axis steppers probably isn't moving - can you rotate the threaded rods with your fingers - it shouldn't take much force, they should feel the same. If you can do this and they are the same check the connections on the controller board.

Go here if you need to see where things fit - https://manual.prusa3d.com/Guide/8.+Electronics+assembly+(B7-R3+design)/823?lang=en

they do move, and I cant feel a difference in force required to rotate them. I did check the connenctions too and the seem to be fine. I also checked the PINDA probe yesterday as I had a feeling that the probe might be bad.

Then one of your Z axis steppers probably isn't moving - can you rotate the threaded rods with your fingers - it shouldn't take much force, they should feel the same. If you can do this and they are the same check the connections on the controller board.

Go here if you need to see where things fit - https://manual.prusa3d.com/Guide/8.+Electronics+assembly+(B7-R3+design)/823?lang=en

good advice and if you were a bit tired or you had misplaced your glasses the E on the extruder connector might have looked like a Z and so those connectors could have been mixed up. when I built my Delta I used hand written tags on everything I found I had swapped one of the tower connections with that of the extruder.... felt rather dumb... but it did get me to change from +1 reading glasses to +2.... I should have wondered why I was reading the newspaper with my arms fully extended...
Cheers
R

I got it assembled and have 45 days of printing time on it, so I dont thing the stepper connections are switched 😉

I made a video when running z calibration:

Re: suddenly no more printing

Something in the top heights it isn't liking, it should get all the way to the top, that's a right odd noise too when it does reach the top, it should come all the way down when calibrating Z and do the reference heights so it is something at the top of that travel it isn't liking - on mine the two bolts on each X carriage threaded insert actually touch the top Z supports, are yours?.

Nothing behind is fouling is it - like a tie wrap on the hot end vs the frame ?

Re: suddenly no more printing

Just a thought. If one Z axis feels more stiff than the other I would check the axis cap on that motor. It might have become excessively tight somehow. I would loosen it and retry the calibration. Another possibility would be that the z axis threaded nut has picked up some debris. I'm not saying either of these is your issue for certain just some possibilities to consider.
DJ

Re: suddenly no more printing

thanks for your help!

when running a calibration to check if a ziptie touches somewhere I noticed that the pindaprobe does blink during homing in x direction. I contacted the support and they are sending me a new pinda probe.

thanks for your help, I wouldn't have noticed it if it werent for your questions!

Re: suddenly no more printing

Glad you got a result, not going to help you print for a week or two but a result none the less.

Re: suddenly no more printing

why not patch the cable out?
regards Joan

Re: suddenly no more printing

My printer refused to start printing yesterday - Z axis failure!
I checked the axis out and it could move freely the whole way up and down.
Tried the Z axis calibration and got the same error when the head went down to around 8cm above the build plate.
Tried it several times and got the same error, always around 8cm but not exactly at the same place (could be more then 10mm different)
Then I noticed a strange behaviour on the led of the PINDA probe. I was ON, went OFF when the Z axis goes up to the top, and went back ON on the way down. At the same moment I got the failure message.
Checking out the PINDA probe in the schematics and manuals, it is an inductive proximity sensor; NPN and NC. This is indeed the proper choice for that kind of sensor, as it should give good diagnostics on sensor failure.
Wobbling the cable tree coming out of the printhead assembly, the PINDA led went ON and OFF by bending the cables even slightly.
This indicated most definitely a broken wire in the PINDA probe cable. Having no intention to disassemble the whole printhead, I removed the spiral wrap around the tree, and stripped the probe cable outer shell at the most sensitive place. Done so, I could feel the cable break in the brown wire. In the sensor world the brown wire is the power. I stripped it and soldered the broken ends together and the printer was working again as it should be.
So far the story.
now the why: the cable was broken some 5cm after the ty-wraps holding the cable tree on the printhead. This seems to me the point where the cable tree bends most of the time while printing. Or was it simply a bad cable? If not this might be a weak point in the design. My printer has some 350 hours of printing and I often print large pieces, so there is a lot of bending.
I noticed all over the internet and in this forum that this kind of problem is not uncommon and indeed generally solved by replacing the PINDA probe.
I wonder how many PINDA probes have already been replaced, while they just have a broken wire.
Second point: This is for you software guys. There is definitely some code in the firmware that's not the way it should be.
1) bringing the Z axis down with the PINDA probe signal OFF - by sensor choice, being equal to sensing metal ( an unpowered probe gives the same signal as a probe touching) is looking for trouble - it could mean there is really something under the head.
2) in my case the probe signal went from OFF to ON while coming down, the moment the wires touched again. This was indeed detected, but with the wrong slope. This is completely illogical in a normal working printer and should be flagged as a PINDA probe problem and not as a Z axis failure.
Doing so would save a lot of trouble searching time for most of us.

And finally some remarks for those of us who try to replace the original prusa PINDA probe by something similar on the market. Specially our US colleagues are not happy with the shipping cost of a 10€ probe to the US.
In my case; the MK3 version, has 4 wires. Looking at the schematics of the EINSY board, the 4th wire is a temperature sensor signal. I did not check it out; the design guys might be able to confirm this; but it makes sense to check the temperature of the PINDA probe, as the detection range might change with temperature and this PINDA probe is not exactly at the coolest place in the printer. So changing this sensor with a common available inductive proximity sensor might give problems, as most sensors in the market don't have this temperature sensor, and even if they have, it should be the same type or the temperature readings are faulty. So only use the original! And if you have a PINDA probe failure, check for broken wires. These sensors are industrial and don't die often. If you don't know how to check them, here a few simple tricks:
- power: the standard color code for sensor wires is brown for power and blue for ground. This sensor is a 5V version, not the more common 10 to 24...30V models. Put 5V on the wires (correct polarity) with a lab power supply and check the current it is drawing. Most sensors consume some 5 to 20mA - no current a all can mean a broken wire. And it has no sense in doing the next step if there is no power on the sensor.
- output signal: a little bit more tricky as this is an open-collector signal. The sensor signal is normally the black wire. Connect a resistor in the range of 2k2 to 10kohm to this wire and the +5V supply, and measure the voltage on this wire between the blue (ground) and black wire. Also check the LED in the sensor. I should light up when the sensor is free and you should measure on the black wire something close to 0V. Having a much higher voltage can indicate a broken black wire in the cable.
If you bring a piece of metal to the sensor head, the led should go OFF (meaning the sensor has seen the metal) and the voltage at the black wire should be at least 2.5V.
- temperature sensor: white wire. Again I did not check it, but I assume there is a thermistor in the sensor. Measure between the white and the blue wire with an ohm meter and I expect something in the range of 10kohm there. Again, measuring something in the Mohm range means a broken white wire.

I hope the guys from Prusa Research read this too and might be able to confirm some of my findings and deductions.

All the Best,

Uncle Victor ( 😉 - part of my radio call name ON1UV)

Re: suddenly no more printing

I'd like to bet that many many failures aren't the device itself. For what it is worth I removed the spiral wrap because it was chafing wires, I've removed all the nylon filament inserts as they generated too much resistance, I've also removed ALL tie wraps from the cable support on the hot end.

My cables are supported only by velcro wraps. The logic behind this is to allow a little flex across a longer length which is desirable vs forcing flex to a single point. This is a similar principle to engineering for high vibration locations where you absolutely don't want solder or crimped joints which create a point of weakness - removing all flex is often a bad idea, the only place that you don't want a lot of movement (if any) is at the point of termination.

I don't even run the braided cable wrap I just have velcro cable tidies every 50mm or so, I have 2 such tidies on the back of the extruder ...

I'm not saying my cables won't fail, they certainly will because that's a consequence of repeated flexing in any system, but I'm a year in, I can't post how many days my printer has been running as it is currently printing but I think it is around 78 days.

Edit : I have currently 1904.43 metres showing on the stats, total print time 77d 22h 58m