Auto Bed Levelling Issue/Bed Damage

[KnoxJA 1]

I appear to be having an issue(s) with my Ultimaker 3. The first problem that occurred was when trying to do a print the message 'Difference between detected height of both PrintCores exceeds realistic values'. I tried to solve this by switching the machine on and off again then printing again, watching more closely I saw that when undergoing auto-levelling the print core nozzle was impacting the glass bed, causing an indent in the bed. Does anyone have any idea how to resolve this issue.?    

 

Many Thanks,
James

[SandervG 1,521]

Hi @KnoxJA, thank you for your post and welcome to our community! 

Before you start the procedure make sure your print core and your build plate are clean and there is no filament in between. Next thing to check is that when the procedure starts, the tip of the nozzle should not yet be touching the glass plate. There should be a space in between. 

The most tangible guideline is that there should be a distance of approximately 14 mm between the bottom of the heated bed and the top of the aluminium base plate. 

If there is more space, you should tighten your springs a little bit with the thumbscrews underneath your bed. 

 

That should do the trick

[KnoxJA 1]

Hello @SandervG
Thanks for getting back to me quickly. The nozzle and bed look clean/ no obvious obstructions, and I have moved the screws on the base plate so there is only a 14mm gap. 

I then tried to do a manual leveling, no issues found. I then tried running active leveling and the nozzle again is impacting the print bed. I can't think what is causing this?

[SandervG 1,521]

Hi @KnoxJA, no problem! Happy to help.

When you moved the screws so there was a 14mm gap, why did you do another manual level? Did you do any more calibrations at this step?

 

When you tried the active leveling procedure again, and the nozzle was impacting the bed. If you measure again now, what size is the gap?

 

Thank you!

[KnoxJA 1]

I wanted to see if doing a manual level would solve the issue, but to no avail. After that and another active level i made no more calibrations.

 

I've measure the gap again, please see the attached image. Appears to still be a 14mm gap. Any other thoughts?

[SandervG 1,521]

That is a little bit hard to tell from this photo. If you put your ruler closer to the corner of your bed (maybe even push a clamp aside) you have a better view of the reading on your ruler. 

And just to be sure, could you also include a photo of your print cores?

 

Thanks!

[KnoxJA 1]

Apologies for the poor quality image. I hope the below is suitable.

 

Many Thanks, James 

[SandervG 1,521]

Thanks, that is much clearer. Interesting. 

Can you tell me if your nozzle is already touching the glass when the procedure is about to start? 

 

Can you tell if there is an approx 14mm gap in the back as well? (top of the glass should be at 1.9/2.0cm height). 

[KnoxJA 1]

Hello @SandervG,

I've readjusted the back screw so that the glass is at 2cm and that seems to have solved the problem.

Thanks for your help!