Hi All,
I decided to try a magnetic print surface to one of our CR10s Pro machines but it won’t lie flat. I followed the Creality tutorial on Youtube but the magnetic surface continually bows up and away from the heated bed.
Am I missing something? Has anyone else had this issue? The magnet sticks dead flat to the steel door of my office, so I’m assuming it’s the layer that goes beneath it on the printer?
Thanks,
Jake
Jake perhaps some pictures and some more details? I understand what you are saying completely. Personally I have never converted a printer but I have used magnetic bed Prusa for ages. What did you do to your machine?
Magnets are funny around heat, you used high heat ones? Regular will lose magnetic power rapidly at temp. Is there anything magnetic on the bed or is it just steel? does the magnetic sheet stay flat on the bed when it is cool or never?
I can’t speak for all of them but the Creality ones that I have have two parts. There’s a sticky (as in peel-and-stick) part that attaches to the aluminium bed (remember: aluminium is paramagnetic, not ferromagnetic - there’s your science lesson for the day). The stick-on is a ferromagnetic sheet. The magnetic build surface then sticks to that. In this photo, they yellow is the peel-off portion, next to the corresponding build plate.
You’ve probably already got a peel-and-stick one on there or you’d be asking why it doesn’t stick at all, not just flat, so on to part two:
If you already have a ferromagnetic surface peeled-and-stuck to your build plate, it may not be compatible with your magnetic build surface. Again, I don’t have any definitive experience with this (ie. I’ve never tried mismatched stick-on and build surfaces), but I have observed that the Creality ones seem to have a magnetic pattern built into them. If you take a Creality surface and place it on a Creality bed, you’ll note that it very much wants to align itself in a particular direction. For example, you can’t just shift it 2mm - it has to be 5mm. It’s like there are magnetic ridges that have to align themselves. If you rotate the sheet slightly, the ridges won’t line up and you’ll end up with bulges.
That’s as far as I can demonstrate because both my magnetic peel-and-stick surface and my build surface come from the same manufacturer.
The point here is that there is evidence for an alignment pattern, so if that’s the case, what if they alignment pattern on your peel-and-stick surface is mis-matched to your build surface (different manufacturer, perhaps)? Then I’d imagine you could end up with regions where the magnets repel each other, even if the build plate is lined-up and centered. Your steel office door and my whiteboard will never have this problem.
I’d suggest a peel-and-stick thin iron sheet to attache the magnetic build surface to. It’ll only have half the magnetism (since only one surface is actually magnetic) and so it will be prone to misalignment but that probably doesn’t matter, but it might also be prone to shifting since the magnetic ridges of a paired stick-on and magnetic base would never allow it and that may be by design. I have to presume Creality et-al went with a two-part magnet on aluminum vs. a thin steel sheet for a reason.
you could test for the alignment issue pretty quickly, try to change the clock position of the magnetic surface just for test purposes, try 180 deg and if you have the room try 90 and 270? maybe one of those ways it will stick down flat then you know its an alignment issue.
Thanks for the advice, folks.
The bulges were exactly like the one shown in the pic posted by LEGOmaniac. I fiddled with orientation of the build surface to the stick-on underlayer and found the surface would lie flat if I turned it 95 degrees from the way I had it installed. However this meant I had to peel off the underlayer, rotate and reapply it then cut some of the width off so it would fit between the uprights on the printer. Now the flexible print surface seems to stay flat and there’s still enough magnetic grip for it to stay in place.
Cheers,
Jake
Honestly, it sounds like a manufacturing error either in the application of the stick-on magnetic sheet or in the manufacture of the sheet itself. Glad you got it working though, but that’s the first time I’ve heard of that particular error cropping up.
I would agree, sounds like a defective product.
shouldn’t have to trim the plates at all for them to function properly
Yeah, I agree this felt like a less than perfect product from the manufacturer. But to clarify it wasn’t the print surface I had to trim, just the peel-and-stick layer. Seems to be working ok now.
I also decided to try one of Creality’s spring steel magnetic surfaces. A bit more expensive, but installed perfectly and it works exceptionally well so far.
Jake
Spring steel, of course, doesn’t have an inherent magnetic field that would have to align with anything, so I’m not surprised it works.
For what little it’s worth, I’ve been pondering how you ended up with a misaligned magnetic surface. I suspect those magnetic mats (stick-on or build surfaces) are probably initially manufactured without a magnetic field. I’d imagine they get put on an electromagnet to get their magnetic fields induced in them and if that’s the case your defective mat obviously wasn’t aligned on the machine properly. I suppose for the thousands that are manufactured, it’s not surprising a few get misaligned.
I’d take pictures and send them to Creality. I suspect they’d send you a new sticker/build-surface pair.
