Build plate blocking nozzle at start of printing

[jimb 0]

I'm new to the Ultimaker printer having only had one for 2 weeks but I now find myself in the position of not being able to print anything.

On all the prints I have tried for the past week the build plate moves hard up against the nozzle and blocks the filament, the shape of the intended print is cut into the glue on the build plate and each time I have to abort to avoid any damage.

I have reinstalled the firmware, Ultimaker 2, and levelled the build plate several times, I have also tried having the build plate lower when levelling, 3 sheets of paper, but nothing has made any difference.

Any advice would be appreciated.

 

[illuminarti 18]

What first layer height are you setting in Cura?

Also, there shouldn't be enough glue on the plate for you to be able to leave a trail in it. Apply the glue lightly (if used at all), and wipe with a wet paper towel, to dissolve all the glue and spread it around, so that when it dries there is a pretty-much invisible film of glue on the bed.

 

[jimb 0]

The layer height is set at 0.1, I have wiped the glue off and will try another print, will let you know what happens.

 

[jimb 0]

Just tried to print the robot but again the plate moved hard against the nozzle, no glue used but can still see the marks of the nozzle on the glass.

 

[gr5 2,192]

Something is wrong with homing. You need to check 2 things:

1) With power off and the bed in the up position look underneath the bed at the brass colored nut that the z screw goes through has 4 screws holding it to the bed. Make sure those are all tight.

2) Sticking out of the bottom of the bed should be a very long (30mm?) screw that sticks down. When the bed lowers it goes down through a hole in the bottom of the UM2 to hit a switch. Please examine that switch. If you lower the bed by hand with power off, does it touch the switch and make a click sound? Consider putting the UM2 on it's side so you can look at the switch as the screw hits it.

3) If the switch seems fine, consider removing the larger cover on the bottom of the UM2 (only 2 screws hold it on) and check the "z limit" signal as the wire traces from the z limit switch to the connector on the printed circuit board.

When you start levelling it does a Z-home procedure where the bed goes all the way down. Does it make a horrible death rattle sound at the bottom? Or does it click the z home switch gently twice?

 

[jimb 0]

With the power off I lifted the bed and the limit switch in the bottom clicks, lowered it by hand and again it clicks, turned it onto its side and watched the limit screw push the switch all the way down again it clicks.

No death rattles when levelling.

Cannot see any brass nut that the Z screw goes through, may be below the bottom plate.

I don't want to start dismantling any further as the machine is only 2 weeks old so if this isn't a problem I can get to without major surgery will have to return it to the supplier.

 

[illuminarti 18]

You should set you first layer height to 0.3mm in Cura.

Also, if you go into the 'maintenance' menu on the printer, and select 'lower buildplate', does the plate go down, click the endstop, bounce up a bit, and them settle down to the clicked position again, without any obvious difficulties or grating noises?

 

[jimb 0]

My mistake the initial layer thickness in the advanced settings is set to 0.3.

Moved the build plate using the Lower build plate in maintenance and it moved up first and stopped, pressed the command again and it moved up and down a small amount without any difficulties or grating noises.

 

[illuminarti 18]

Turn the power off. Grab the bed towards the back, and lift it into a middle position. Then power printer on, and try to lower the buildplate. See if it goes all the way down and bounces, cleanly.

 

[gr5 2,192]

The brass nut I was talking about actually isn't visible from the bottom. You don't have to take anything apart - just raise the bed and look at the 4 screw heads closest to the big Z screw from below. Make sure those 4 screws are tight. That's all. This was a problem for someone else who was constantly losing his level due to the bed being loose there. Personally once I set my Z level I don't have to touch it for a month.

 

[jimb 0]

Checked the bed movement as described, moved into centre of z screw then lowered it on maintenance settings, it goes down cleanly and then bounces at the bottom without any noises or rattles.

Checked the tightness of the four screws, each turned about an 1/8th of a turn so not loose then tried to print the robot, it worked although the print quality is very poor as it is dragging the filament across the print, neither of the fans were running at the start of the print is this normal.

Will try another print when the robot is finished and let you know.

 

[gr5 2,192]

Photos or video might help.

Did you use paper to level? It sounds like it's just a tiny bit too close (nozzle to bed). I don't understand why you level and then it seems to ignore your levelling.

 

[jimb 0]

Printed three different objects today without any problem. it looks as though tightening those four screws that hold the Z screw brass nut did the trick, thanks for your help and advice.