UM2+ Connect Manual Leveling, can't lower bed any further. Printhead still too close to bed.

[Ferryy 0]

The Ultimaker 2+ Connect unfortunately doesn't have active bed leveling. When I was performing the build-in manual leveling procedure, I ran into issues with the front-right screw. It was impossible to lower the buildplate further since the screw is tightened all the way. Hence printing the first layer goes poorly due to the small space on this side of the bed.

 

I suspect that I have to adjust the small Z-Limit screw (to lower the complete buildplate) which is in the back under the buildplate, but I couldn't find any instructions on how to do this. How can I open up the white cover on the back without breaking anything?

Edited October 5, 2021 by Ferryy

[Smithy 1,146]

I think it is enough when you slightly bend the end switch in the bottom back to "adjust" the end stop of Z.

So when you are too high you need to lower the bed, so bend the switch down just a little bit.

[w_bronkhorst 0]

Today I have opened the box of a brand new Ulitmaker 2+ Connect. I am experience the same issue "manual leveling, can't lowe bed any further. Printhead still too close to bed."

 

The Printhead bows the glass buildplate both on the left and right front side. You hear the nozzle touching the bed. The Z-Limit screws are not 'long/short' enough to perform the job. 

 

The proposed solution is not clear for me. Can you eloborate furhter?

 

[MarkusBaumann 6]

At my UM2+Connect the distance from the top surface of the aluminum tray to the top surface of the glas is quite exactly 20,0mm when the bed is levelled.  The adjusting screws are dragging the builplate down against the force of the spring. Between the aluminum tray and the adjusting screw there is a washer. If this is missing, perhaps the travel of the screw is to short to lower the buildplate low enough. At my printhead the distance from the nozzle tip to the bottom side of the lower aluminum plate, where the hot end is mounted, is 18mm. Perhaps the nozzle is not all the way in.

 

On the bottom side of the aluminum tray between the z-spindle and the left guiding rod there is a screw pointing downwards which is switching the limit switch in the bottom of the printer. If you bend the lever of the limit switch slightly down, the home position of the whole tray will be slightly lower. Perhaps this will give you the fraction of a mm which is missing. If you only have the problem at the front screws, perhaps the tray is bent? Adding washers at the front adjusting screws probably will help.

[w_bronkhorst 0]

I have returned the printer to the vendor. 

[MarkusBaumann 6]

What was causing the problem? Were you able to identify it?

[dfrez 21]

Old thread but sharing in case someone has the same issue and stumbles on this thread. 
 

I just bought a UM2C and had this exact issue, the front right thumb nut would bottom out but there was still no gap between the nozzle and glass. I’m confused why UM got rid of the initial rough adjustment that the UM2+ has in it’s leveling procedure, where you rotate the control knob until the nozzle is about 1mm away. It would prevent an issue like this. 
 

Anyway, I solved this by swapping the limit switch screw on the buildplate carrier. Originally it’s a M3x16mm, I replaced it with a M3x14mm. I prefer this over bending the limit switch, I couldn’t get it to bend enough and I was worried I’d break it if I tried pushing harder

 

Simply pop off the back cover and use a piece of blue masking tape to hold it to the top of the printer to keep it out of the way. Then remove the screw to the left of the lead screw and replace with the shorter screw.