I ordered two different pla spools, one a generic spool and the second a name brand. The generic came first and I tested it 3 times trying to print a 2 1/2 x 3 1/2 box on a raft. I tried to adjust the bed an nozzle between each test. Each time first the raft curled and then the box on the corners. After a couple of hours when the printer would return to one of the liftet corners the nozzle would grab the entire print and pull it off the bed.
When the name brand arrived I tested it using the final setting from the last generic test. I first printed the box and then the cover. Each time the raft stuck to the bed and the box / cover to the raft. If anything the adhesion was too strong, it was difficult to remove.
My speculation is the generic PLA is shrinking more then the name brand.
My questions are:
1. Is this a common observation. Is it normal for different PLA to have different shrinking charactoristics?
2. Beyond trial and error is there a way to tell before purchase how a PLA will behave?
3. Is it as simple as find a brand and stick with it?
Thanks, Dan