Magnets! How do they work??
Ok, so this may save some time for someone else in the future. I have a Prusa i3 Mk3 Kit that has been acting up a lot lately, The front right corner of the bed seemed to be super under extruded as well as a spot in the middle. I took the bed apart to make sure my rails and the heated bed weren't twisted, bent, mangled, etc. Then I noticed it, three of my magnets that were supposed to be attached to the bottom of the heat bed were missing!
I eventually found them, one was under the right z level motor, two more were attached to the bearings.
Right now, I've reattached them with some CA glue hoping that solves my problems.
Just a heads up for someone who might be in a similar situation, whatever is used to glue the magnets down isn't really holding in some cases.
I'll reassemble tomorrow and see if that helps after calibration.
Re: Magnets! How do they work??
You're not alone: https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/what-kind-of-glue-to-use-for-re-attaching-magnets--t19249.html
Re: Magnets! How do they work??
Just an update to my initial post:
The CA glue seems to be holding up and after recalibrating XYZ, it's pretty much back to normal (I am still having first layer issues but it's crap PLA and my Z needs to be fine tuned).
So, yeah...magnets!
Re: Magnets! How do they work??
I am thinking for those who insulate their heatbeds would not have this problem as the insulation would stop the magnets from dropping out of their slots even if the magnet adhesive fails.
Regards
Martin
Martin Wolfe
Re: Magnets! How do they work??
The maximum service temperature rating for CA (well, the one I'm using anyway) is only 82C: http://www.loctiteproducts.com/tds/SG_UG_CNTRL_tds.pdf
That said, I haven't yet had any that I've re-glued fall out, even though I often use a bed temp of 90C.