PEI bubbles
So I've been printed several large parts repeatably with ABS and have started to get some large bubbles in parts of the bed (largest being about 2cm by 1cm). I'm guessing it is being caused by the ABS shrinking as it cools and pulling up the PEI sheet in certain spots (and printing the same parts over and over probably exasperate it more). It's not a huge problem yet other than some minor first layer missing at those spots, but was wondering if anyone has encountered a similar issue and have a way to correct it without replacing the PEI.
I've tried pressing down on the PEI trying to smooth these bubbles out, but I have a feeling that the bubbles are actually stretched PEI and there isn't a quick easy solution.
Re: PEI bubbles
The Prusa I3 as an open frame printer and is not the best printer for ABS. I suggest printing with a raft with ABS. And see if that is an improvement. Long dimension prints with any filament I use a raft, and have had great success. Your slicer of choice should allow a raft. Simpilfy3D is the slicer program I use.
Nigel
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Re: PEI bubbles
leif.j: its normal, bubbles will dissapear in time.
Re: PEI bubbles
I've been printing with ABS for the past 4 years so I'm quite comfortable with using it. I have my printer in an enclosure, it's one of the first things I did after assembling the printer. I do print with raft and brim, so I am guessing the problem stems from the PEI being so thin and the adhesive just is not strong enough as the ABS shrinks. I use PEI on my Rostock, but it's far thicker (1/8") and do not encounter this on the same prints. So when I decide to re-do the PEI sheet, I'll probably pick up something that is a bit thicker and less prone to deform.
Re: PEI bubbles
In addition, the way you unstick the object may influence that.
If you unstick a corner and push a spatula below the object, the effort on the PEI sheet will be less important than if you try to rotate the object on one of his edge.
I'm like Jon Snow, I know nothing.