Calibration failed, check the axis and run again......and again...ad infinitude
Good afternoon,
I’ve pretty much spent the last 5 days trying to resolve this problem. And yet it persists....I’m pretty sure it’s either a firmware problem or an intermittent problem with the PINDA 2 probe. But having gone through many threads on this and other fora, I’m none the wiser.
The printer is a Prusa Mk2.5 S which I bought as a kit a few years back and worked well. I’ve done the 2.5 upgrade. I am running 3.9.1 3581 but the problem also exists on 3.8.1-2869. Sadly the upgrade didn’t clear it.
Following the advice on this and other fora this is what I’ve tried so far :-
1. Verified that the hardware is assembled correctly, the angles are correct as are the dimensions. I’ve checked these with vernier calipers and an accurate electronic level. All nuts and Allen bolts are tight and the belts are tensioned correctly.
2, Done several resets to erase saved calibration data,
3. Checked and lubricated the rods, movement screws and steppers with appropriate lubricants.
4. Ensured that the wire from the PINDA to the control board is not pinched. Checked the PINDA holder for cracks,
5. Used feeler gauges to set the height of the PINDA above the nozzle from 2 mm to 0.5 mm, nothing seems to work.
6. I’ve noticed a couple of unusual things which makes me think it might be firmware. Auto home takes the sensor to target circle, half in and half to the right. Calibrate Z does an Auto Home before the “raise the Print head dialog” but it takes the sensor to the target circle, half in but half below. Secondly sometimes I get asked to put a sheet of paper on the print bed during calibration, other times not. What’s very frustrating is the lack of meaning in the error message. It just seems to be a catch all, useful to to the programmer but useless to the user.
7. What makes me think it may be a PINDA issue is that, whilst the probe detects the presence of metal and indicates this to the firmware, when the PINDA gets near to the surface of the hot plate the red LED goes out. I’d expect this, but I can switch the LED on and off by touching the plate. Now it could be that my finger is distorting the plate just enough to switch the sensor off. Which would mean the sensor is ok. But if that’s the case why doesn’t altering the height of the sensor make a difference? And, as an aside, the holder needs redesigning. It’s terrible.
I’d be interested in any comments, especially from people using the same setup as I am. My next step is probably to revert to some older software and see what happens.
Regards,
s
S
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Hallo stephen-f2
I would try the following. There is a menu on the MK2.5 where you can have the view to the values of the endswitches and the pinda. So turn on the printer, turn z to a positive value 20 to 30 mm should be enough, than turn steppers of. switch to the menu where you can see the sensor readings of the endswitches and move x-axis very slow from complete left to complete right (very slow) and have a look to the display - is the value for pinda changing? If pinda is ok it should have the hole time the same value (I think it is 0 - but more important is, that the value is not changing).
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Another point:
Good value for Pinda height is 0,8 to 1,0 mm above surface of printerbed (with sheet on top of the heatbed)
When you reset the printer to factory state - have you done the complete Wizard - is your error occuring already when pinda should report first point? (Before auto bed leveling could start?)
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
If you are a normal human (no metal hands or fingers) pinda should not change its value when you come closer with your fingers! If taking a screw driver or another tool - pinda should do a switch in the value.
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Clemens,
Many thanks for your replies. I’ve tried the end switch test which you suggested and it looks like the Pinda is ok. I also did a complete factory reset followed by the calibration wizard, after the end switch test. Every test passes until it tries the Z axis test and fails with the same error message as before. I’ll reset the pinda height later today and try again.
When the Calibration wizard does the Z axis test it asks for paper on the bed. If I use the calibrate Z axis it doesn’t ask for paper. Both of these fail with the same error...
I don’t have metal fingers 🙂 .....
thanks again,
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Clemens,
I’ve ordered a replacement PINDA. I’m not sure it’s faulty but it wasn’t big money. I’m anxious to get the problem resolved so I can start 3D printing the parts for my home made microscope.
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
@stephen-f2
One thing - I don have it in mind right - but I know that when doing the Wizard (which takes approximately 10 to 15 minutes) it could be, that the springsheet has to be off the heatbed - and maybe that is, when you have to use the sheet of paper.
What kind of microscope are you printing?
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Hi again,
I followed the instructions exactly. The wizard asks for paper for the z calibration. The individual z calibration doesn’t.
Here is the microscope design. It’s incredibly impressive
https://www.bath.ac.uk/announcements/print-your-own-laboratory-grade-microscope-for-15/
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
@stephen-f2
I am watching this open source project for quite a while - very impressive, every time I have a look to their homepage they have improved it - one time I will build one.
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Greetings from lockdown England,
Well the new PINDA arrived and I’ve fitted it. That wasn’t the cause of the problem. I’ve checked the trapezoid nuts. They are ok. I’ve reverted to an earlier version of the firmware (from 3.9.1 to 3.8.1) which also doesn’t clear the problem. I’ve reset the stored data. But the problem persists. I’ve spent a week trying to resolve it now, plus the cost of a new PINDA. I’ve read lots of messages on lots of fora about what the message is supposed to mean and how to fix it. But the suggestions are mostly guesswork because no one seems to have a definitive answer about the meaning of the error message. What cures the problem for one person fails for another. From what I’ve read Prusa support are also none the wiser. Short of downloading the source code and looking through it, with my limited knowledge of C++, I’m lost as to what else to try. This issue has been known about for several years but whoever maintains the software and documentation doesn’t seem to have done anything about it, which given that Prusa are selling a premium product is not encouraging.
I really am very disappointed
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Have you restarted the full wizard, from start to finish? Not just the Z portion? After a reset, you must run the entire initial wizard and setup since all of the cal constants the wizard records are deleted with reset.
https://help.prusa3d.com/en/guide/5-preflight-check_63088
RE: Calibration failed, check the axis and run again......and again...ad infinitude
https://help.prusa3d.com/en/article/misaligned-pinda-sensor-mk2-s_2016
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Hi Tim,
Thanks for your advice. I’ve tried both of your suggestions. But am no further forward. I’m just about to carry out a continuity test of the Connector which connects the Pinda probe cable to the RAMBO board. I’ve some suspicions that whilst the Pinda probe is triggering that is not always being recognised by the board. But it’s only a guess. It’s just as well I know something about electronics and firmware because if I didn’t I’d have skipped the printer by now.
Regards,
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
If the red light is working, it means the pinda is detecting things. On a MK3, you can verify operation in the menus: under sensors you can see the PINDA state moving off to on. Not sure if the Mk2.5 has that menu...
ps: in any case, at this point I really can't do much more than to offer condolences and good luck fixing it. You might try contacting Prusa via their CHAT on the store website. Maybe they have ideas.
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Tim,
thanks so much for your help. I’ve spent a couple of hours this afternoon on the problem. I’ll start again in the morning. From what I’ve read the Prusa support people can’t deal with this problem. They have a script and I don’t want to spend even more time going through all the things I’ve tried before. I’m minded to revert to an even earlier version of the firmware as I was happily printing face masks in April and all was well.
Regards, Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Hi Everyone,
I’ve solved the problem which comes down to me misunderstanding what firmware I needed. I started with a 2s, then did the upgrade to 2.5 which I misunderstood to be 2.5s. This is quite a logical mistake to make so I installed the wrong firmware. I’m not the only person to have done this. What really threw me for a long time was the fact that it sort of worked. Having got the calibration to work well I’ve discovered that the filament sensor is dead. But that’s not essential
Thanks again for the help,
Steve
RE: Calibration failed, check the axis and run again......and again...ad infinitude
Good that you made it work. Regarding filament sensor: You know that you can turn it on and off in one of the menue´s of the printer? Have a look. Maybe it is only switched off.
Best regards, Clemens
Mini, i3 MK2.5S, i3 MK4, CClone (Eigenbau)
RE: Calibration failed, check the axis and run again......and again...ad infinitude
@clemens-m
Hi Clemens,
Thanks for getting back to me. I’ve disabled the sensor setting for now as I don’t really need it.
Regards,
Steve