Cura 4.1.0 when printing one at a time prints the second model below bed level

[BlackboardIdeas 0]

Hi,

I had problems printing 2 parts at the same time so I made them print one and then the other. I left, because I had to go shopping for food, and when I came back, one model was nice done ( the first one), but the other was stuck to the print bed like crazy and when I removed it and measured it with calipers in the Z direction, the second model was about 3mm lower than the other and the ultrabase below it was all scratched up and the nozzle will probably need itself being replaced. From what I saw I can surely say that something (probably cura) made the second print start 3mm below the bed level, resulting in my bed being destroyed, luckily on almost the very edge. I had it leveled and when I checked the bed screws, none were loose. Leveling the bed afterwards wasn't necessary, the bed was completely leveled and the distance between the bed and the nozzle was the same everywhere, just the very tip of the nozzle got brushed off. If it is really the Cura's fault, it should be fixed ASAP. I was very lucky I didn't print it in the center and that it was a very small object, so I don't have to replace the whole print bed due to this. Anyone has any ideas what could this be caused by? Thanks.

[BlackboardIdeas 0]

Got the nozzle exchanged, but please, could someone reply? If it's a bug, it's quite dangerous for one's printer.

Edited August 24, 2019 by BlackboardIdeas
Typo

[XYZDesignPro 70]

I my experience CURA does not do a very good job at "printing one at a time" 

What printer are you using?

You might want to refer to the links below:

https://community.ultimaker.com/topic/24945-object-distance-by-printing-one-at-time/

 

[johnse 31]

I don’t think this is Cura’s fault. If you were to examine the gcode, you would likely find it directed the correct moves.

 

i suspect, and this is pure speculation, that during the printing of the first object your z-axis slipped a few steps. Then on the move back to the first layer, it didn’t miss those steps and thus travelled further down than it did going up on the first print.

 

I would clean and lubricate the Z axis and run some calibration tests.

[BlackboardIdeas 0]

I don't think that it missed some steps, the first model had perfect dimensions in the Z axis. But yes, my Z axis rods do sometimes make rumbling noise when moving, which is probably caused by bad lubrication of the rods. I'll try lubricating them and I'll let you know. Btw can I use WD-40?

 

Also you wanted to know what printer do I have. I have Jgaurora A5.

[johnse 31]

Not WD40!

 

On the z axis screw, use magnalube.

on guide rods, use light machine oil—like sewing machine oil.

 

WD-40 is not primary a lubricant. WD stands for Water Displacement. It does have a light lubricant as a carrier.