Auto leveling

[sux4x27 0]

Hi,

 

I recently bought a used UM3, and I have two questions. First one is how long schould heating the build plate take. I think it takes very long, and if I want to print cpe+ it sometimes even times out stating it takes too long to heat the build plate.

Second is about auto bedleveling. When the printer probes the bed, the nozzle doesnt just gently touch the buildplate, but the buildplate moves up against the nozzle so that the nozzle pushes the bed down into the springs by at least one mm.

When printing after auto bedleveling the buildplate is far too high, causing the nozzle to scrape along the glass trying to squeeze the plastic into the buildplate, but nothing comes out because its so tight against the glass. The only way to get that corrected again is by turning off auto leveling and level manually again.

I think I read a post about the leveling issue before, but without any solution. Any thoughts or tips?

 

Regards,

sux4x27

[Smithy 1,145]

I can only speak about my experiences with heating the bed. It takes long and even longer if you go higher with the temperature as you do when printing CPE+. It helps a lot if you cover the printer, close the front and even cover the top. Any cool air from the environment can result in a longer heating time.

 

4 hours ago, sux4x27 said:

When the printer probes the bed, the nozzle doesnt just gently touch the buildplate, but the buildplate moves up against the nozzle so that the nozzle pushes the bed down into the springs by at least one mm.

This is normal. The leveling process measures the capacity between the head and the build plate. So the build plate moves up and the value changes continuously. Then the nozzle touches the glas and the bed moves a little bit further but the value doesn't change anymore. That is the point the printer knows he has reached the glass and calculates the correct leveling.

 

4 hours ago, sux4x27 said:

When printing after auto bedleveling the buildplate is far too high, causing the nozzle to scrape along the glass trying to squeeze the plastic into the buildplate, but nothing comes out because its so tight against the glass.

Hmm, strange issue, I cannot confirm this behavior. Yes the nozzle is close and the material is squeezed into the glas, but that is important for a good bed adhesion. But I haven't seen that the nozzle scratches the glass or is so close that nothing can be extruded.

[sux4x27 0]

Hello Smithy,

thank you for your reply.  So the bed moves up until the value stays constant. that makes sense. (although it looks a little brutal).

After autoleveling, the bed really pushes against the nozzle, so the the it gets pushed down a bit. When printing a brim I can see the traces in the glue I have applied on the glass.

I have done manual leveling and then auto leveling several times now, with the same result. So Im not using auto anymore now, but Id rather do.

 

Regards,

sux4x27

 

 

Edited November 14, 2020 by sux4x27
typo

[Smithy 1,145]

Maybe your glass is not really flat? 

But you can also turn off the auto leveling completely, for the size of the bed it is not really needed and you are much faster with starting a new print without the leveling. I have turned it off and just do a manual leveling again after a few months.

 

Another workaround would be to install the z offset plugin in Cura and adjust it to your needs.

[eric_huang 0]

On 11/15/2020 at 2:50 AM, Smithy said:

I have installed "z offset" Cura, but how use it?

 

On 11/15/2020 at 2:50 AM, Smithy said:

Maybe your glass is not really flat? 

But you can also turn off the auto leveling completely, for the size of the bed it is not really needed and you are much faster with starting a new print without the leveling. I have turned it off and just do a manual leveling again after a few months.

 

Another workaround would be to install the z offset plugin in Cura and adjust it to your needs.

 

[eric_huang 0]

40 minutes ago, eric_huang said:

I found it~ Thanks