Build plate changes Z position with temp

[J_Svensk]

Hi

I´ve used this printer for some weeks now and it works quite well, but I have noticed that the build surface position moves a lot depending on the current heatbed temperature. Is this normal?

When the bed is warm it´s closer to the nozzle then if it´s cold. The difference is so big that if I calibrate it cold, then the nozzle gets in contact with the bed and make scratches if I print PLA on a 60 degree bed. I print a lot in both PLA and ABS and I need to turn the Z-calibration screw 0.5 turn when I change material and need to go from 60 to 100 degree bed.

I think this is very annoying and it´s also a big risk that the bed will be scratched since we are several people that uses the machine with both PLA and ABS.

Does anyone else encounter this issue?
Is there any way to fix this?

[Trhuster]

Yes this is normal. More heat makes the metal to expand. What you can do is to use global offset Z. For your ABS profile you can for example put in 0.1mm or what you think is the right number.

[J_Svensk]

Thanks for your reply! That is a great way to handle the issue. I just need to do some tests to see what Z offset that is suitable..