Pilou, if you compare the little knobs on the bottom of the raft. Are they significantly smaller in the area that lifts up? I still suspect that your bed is hanging on corner. How long do you wait after switching on before you print?
[quote name=Andre]Pilou, if you compare the little knobs on the bottom of the raft. Are they significantly smaller in the area that lifts up? I still suspect that your bed is hanging on corner. How long do you wait after switching on before you print?
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Yes Andre, the little knobs on the bottom of the raft are way smaller in this corner than in other parts of the raft. What does it mean ? I usually wait for 15minutes before starting printing.
Put your gloves on and turn the ball screw so that the platform is almost touching the nozzle in the center position (printer off). Then move the head slowly be hand to the area where you have adhesion issues. If you see the distance getting bigger then adjust the platform further…repeat until the distance stays equal. Do that all over the platform. Make sure the ball screw does not spin when you move the head around (hold with gloved hand)
If you have Acetone use it. This worked for me. Take an old piece of raft. Rub it with an Acetone soaked towel. Rub the sticky residue from towel on the white part of perf board. No more problems!!! I did hit the white part of perf board with sand paper before I did this. Wipe all dust off with Acetone after sanding.
Guys!!! I sanded the surface of the platform with 600 grit sandpaper and the adhesion problems are completly gone (welll, that and some calibration made the trick) I just sanded a little, the perfboard still a little shiny, after that I cleaned the surface with acetone.
Here’s an other thing that works fine for me if you don’t want to “destroy” the platform.
If the platform heating up, some material of the platform expand more than others. So if the top surface is flat before heating, it isn’t afterwards.
So my solution, i don’t fasten the screws before heating and when hot, i only fasten the screws at the back edge where the connectors are. so the platform is absolut flat during printing.
BTW don’t remove the screws your not fastening. Just release them a little!