PLA STUCK to bed + other issues

K8200 3D Printer K8200 - Issues while printing
1
  1. Objects REALLY sticking to bed
    Be careful what you ask for !!! Originally I had problems getting items to stick to the bed
    Now I am having a problem that the PLA items I print are stuck REALLY hard to the bed.
    I have to peel the masking tape off the bed to get the item off and sometimes the tape actually tears around the object and the objects stays stuck to the glass (through the tape)
    I use a 50 degrees c heated bed with Velleman tempered sheet of glass and the blue masking tape
    At the moment (starting) I am printing trolley euro coins for testing so they are quite thin (approx 2.5mm) and they are hard not to damage when removing from bed.

Any suggestions (less bed heat ?)

I have just fitted the K8204 Zaxis upgrade provided by Velleman (and subsequent firmware upgrade) but I don’t think this is the issue above

All my object dimensions are pretty much 10% off when printed and compared to original drawings (both W X H).

I am disappointed the Zaxis upgrade didn’t at least fix height issues.

Any pointers how to go about fixing this ?

Mods
Precise Z-Axis Home Calibration V1 thingiverse.com/thing:317411
K8204 Velleman 3D Printer Z-Axis Modification theelectronicsshop.co.uk/con … k8204.html
3D Printer Glass Plate GP8200
3d Printer ring light

2

With bare (clean) glass at a temperature of 70 degrees (65 measured) for the first layer, dropping to 60 for subsequent layers, my PLA prints are difficult or impossible to remove at the end of the job, but break loose easily once the bed temperature has dropped to 50 degrees.

3

Regarding 1: I experienced this problem when the nozzle was too close to the printing bed. You can test this without calibrating if you simply turn the z-axis to go up after RepHost has homed it after the printing bed got hot enough.