Ultimaker 3 active levelling failure

[JO3 1]

Hi All,

I'm just having a bit of an issue at the moment with my UM3. I did a factory reset and went through the setup including manual levelling, however, when I went to do active levelling it came up with this error message:

'difference between detected height of both printcores exceeds realistic value'

When active levelling it seems to be measuring to the wrong nozzle, i.e it will measure to the nozzle that's up. It will then switch nozzles and measure to the opposite one.

I'm not sure if anyone else has had this issue?

Thanks

[DidierKlein 729]

Did you try it more than once?

I had this but usually the second time it works fine, i think it can happen when some residues are on the nozzle tip (not sure)

[tomnagel 126]

* You did a factory reset. Maybe that has caused the printer to forget the exact position of the switching bay. there is a procedure to calibrate the location of the switching bay.

* another possibility is that your bed is too high. Look closely when the leveling procedure starts. The bed goes up at a high speed, and should stop 1-3mm below the nozzle. Then, it slowly (0.4mm/sec) moves up.

If the bed is too high, the bed is already touching the nozzle when this procedure starts. It then cannot find the nozzle, and will lift the lower nozzle until it hits the 2nd nozzle. Use the screws below the bed to lower it a few mm.

* Third possibility is that there is plastic on the printbed or on the nozzle. Both should be clean.

Edited March 15, 2017 by Guest

[neotko 1,417]

Maybe then after a factory reset the user should be prompted to do a x/y/z/switch calibration?

[tomnagel 126]

As a matter of fact, for XYZ calibration this warning is given. However, what happens with switching bay location data I don't know.

[budde 1]

We actually had the same issue. However, we did not do the factory reset before, but also kept receiving the error message after having first done manual leveling and then active leveling.

We repeated the manual leveling 10 times or more without success (also with the bed in the lowest position, freshly cleaned, etc.) until by accident we stumbled upon the solution, or at least something that worked for us: In manual leveling, there are several steps, some which require you to adjust the plate height with the jog wheel and some that require you to adjust the thumb screws. Normally, when prompted to adjust a screw, the jog wheel is disabled. However, when we accidentally used the jog wheel instead of the "middle back build plate screw" in the respective step, we realized that is was enabled. We then suspected that the step-by-step tutorial is maybe faulty and that you should actually use the jog wheel instead of the screw (only in this step). So we did that and ta-daa, afterwards, active leveling and consecutive printing worked like a charm.

So either this is a huge coincidence, or there is actually an error in both the manual and the step-by-step tutorial that is implemented in the printer. Don't know if this helps you, but it ended our leveling problems.

Either way, what's not so great of course: either the manual is faulty, or the manual calibration process does not work adequately.

[adshale_de 0]

I also am having this issue. Brand new Ultimaker 3 Ext, delivered on Monday, and did the latest Firmware update today. I haven't previously used dual extrusion, as only did a test print on single extrusion. Today, asked the print to do dual extrusion and it tried to auto calibrate but failed.

On active calibration, it lowers 2nd print head and then tries to calibrate 1st print head, then raised the 2nd head and pushes the frame of the print head into the surface because the 2nd nozzle isn't "present". It is almost as if the auto-calibration routine has the "raise print head" the opposite way around.

I have managed to manually calibrate the bed, but auto calibration after manual hasn't fixed the issue. Would prefer to automatically have it do the levelling as I would prefer to do this before each print job.

[Oj00 5]

Hi, 

 

On 11/30/2017 at 1:06 PM, adshale_de said:

I also am having this issue. Brand new Ultimaker 3 Ext, delivered on Monday, and did the latest Firmware update today. I haven't previously used dual extrusion, as only did a test print on single extrusion. Today, asked the print to do dual extrusion and it tried to auto calibrate but failed.

On active calibration, it lowers 2nd print head and then tries to calibrate 1st print head, then raised the 2nd head and pushes the frame of the print head into the surface because the 2nd nozzle isn't "present". It is almost as if the auto-calibration routine has the "raise print head" the opposite way around.

I have managed to manually calibrate the bed, but auto calibration after manual hasn't fixed the issue. Would prefer to automatically have it do the levelling as I would prefer to do this before each print job.

This is a similar issue I've experienced before. The heads don't have separate sensors. The way the leveling works is that the capacitive sensor is used to detect the glass bed, however the software only detects when the capacative reading stops changing. (i.e when the bed contacts the nozzles the sensor reading stops changing and it knows it is in contact) 

 

How ever if the bed screws are wound right out the bed is very high off of the aluminium plate then the nozzles will contact the glass before the system starts to look at the measurements and it continues to push into the glass. 

 

The simple solution, wind the bed down a few turns on all of the bed leveling screws and try again. The nozzles should not be touching the glass when the bed has rapid-ed up, and before the bed is moved slowly up to touch the nozzles. 

 

If the issue continues you may have a defective sensor, which I have heard of before. Also check there is no debris on your nozzles or glass bed. 

 

[adshale_de 0]

It doesn't rapidly move into the glass - there is a gap after it rapidly moves, and it slowly moves towards the glass, and then continues to move into it once it has made contact. I actually half expected to hear a "clink" of cracked glass the force it was applying! The head is clear of debris, and I have tried removing both print cores and re-seating them, in case there was an issue with this; exactly the same as before.

 

Is there a way to test the capacitive sensor?

[Oj00 5]

How large is the gap after the rapid? 

 

I don't believe there is an easy way to test the capacative sensor, if it is a new machine and has never performed this auto calibration correctly I would contact your re-seller and ask for a machine swap.

[fbrc8-erin 302]

Try tightening the thumbscrews on your bed until the heated bed plate is about level with the lip of the base plate at the front (pictured below). I generally find if it's not an issue with filament on the nozzle or debris on the bed, it's the height.

[3DSMITHY 0]

Budde,

 

Thanks... after 10 hours of learning a few ins-outs of the new machine, active leveling now works!

Must have been an error in translation between "turn the turning things" and specific screw / jog wheel.

Am printing a first article with PVA support now and fingers are crossed.

This U-3 is a big difference from my faithful, 3 year old TAZ 5.

I'm really going to miss the ability in Lulzbot's version of moving extruders, beds and filament right off the Cura interface.

Thanks again!