Bed leveling problem with Ultimaker 2

[tonym 0]

Hi,

I got my ultimaker 2 yesterday and can complete the levelling procedure without issue just trapping the paper between the nozzle and plate on all 3 locations.

The issue is then when coming to print it starts approx 0.5mm above the plate (visually you can see a huge gap between the nozzle and plate).

The way i have got around this issue it to repeatedly run the minicaltest and adjust the bed during this process.

It seams the z0 on the print level and the z0 on the print are not the same, is this normal?

Cheers.

 

[jonask 0]

You level your bed with the three screws under the buildplate, right? I did miss the third screw and the back of the build plate when i first leveled my UM2.

If you are using Cura, check your "initial layer thickness". Its set to 0.3 on standard. You can try to lower it. Im using 0.15 for all Prints right now.

I think cura takes your bedleveling and then add some height related to the first layer thickness.

I level my bed while im printing a really large cube (or something that prints a large area for the first layer. You can also take a small cube and print a really large skirt around it). Just repeat printing the first layer and level the bed with the three screws underneath the build plate, until you fine with he result. I set initial layer thickness to 0.15 on all prints so its always the same first layer thickness.

 

[gr5 2,167]

.3mm is better first layer as you don't have to be quite as precise when levelling. .15mm is for experts (or patient people who spend hours leveling maybe).

Level it one more time. It should just barely bite the paper - you should feel a small increase in resistance at each of the 3 spots on the paper.

The paper should be average paper used for ink jet printers, photocopiers. Not thick cardboard stock.

Typical paper is .1mm thick and after you "level" Cura moves the bed *closer* by .1mm to be the Z=0 point. Then when printing the first layer it moves to Z=layer height so for .3mm layer it would move to Z=0.3.

 

I think cura takes your bedleveling and then add some height related to the first layer thickness.

 

It subtracts the 0.1mm.

 

[tonym 0]

Thanks guys,

I am out all day today but will try again on my return.

The main issue is when the nozzle is so far away the PLA does not adhering to the glass, it is cooling before hitting the glass then just getting dragged around the plate and sticking to the nozzle.

Each time i have levelled i ensure that it nips the paper on all 3 locations. I can get great prints when running the minicaltest and tweaking the height by eye as it goes around the bed perimeter but its a real pain to keep doing this.

 

[3dmakeme 0]

Hi,

Just to complete advices, i'd like to relate another possibility.

I experimented what follow:

 

• I correctly made my bed levelling
  
• At each print, i was still away by 0.5 cm !!
  

I first thought i was doing something wrong. I made it 5 times and was always away from the plate by 0.5 cm !

So i decided to check my model. It was a sketchup model. It turns out i had a tube with reverted faces à 0.5 cm of the bed level. I reverted the faces, exported the STL again and made the gcode with Cura.

It turns out this was the problem and never had bed levelling problem again.

Hope that helps !

 

[gr5 2,167]

Make sure you always check your sliced model in "layer view". You can save yourself lots of trouble - you don't want to find out you have something wrong with your model (from the slicer's view) when you get 10 hours into your print!

 

[stevegt 1]

Hi Tonym,

I was seeing the same symptoms, a bunch of us have finally narrowed this down, and a firmware upgrade will be out shortly -- watch for 14.06.1. There is also a workaround you can use now: see http://umforum.ultimaker.com/index.php?/topic/5935-z-axis-homing-inconsistent-on-um2-workaround-and-patch/ for details.

Steve

 

[tonym 0]

Hi Tonym,

I was seeing the same symptoms, a bunch of us have finally narrowed this down, and a firmware upgrade will be out shortly -- watch for 14.06.1. There is also a workaround you can use now: see http://umforum.ultimaker.com/index.php?/topic/5935-z-axis-homing-inconsistent-on-um2-workaround-and-patch/ for details.

Steve

 

This is great news.

I never did get to the bottom of the issue, thanks for updating this!

Tony