@bearer said in New bed, from scratch.:
I can't say I got very scientific about this, but seems the magnet doesn't care very much if there is air, cardboard or aluminium between it and the steel sheet. And even at 1mm gap a handfull magnets provide ample holding force (or so I would think)
But I've been told I can have the 120C/250F magnet sheet "smuggled" to me in a couple of months, so I'll skip trying to mill out pockets for magnets this time around. Mostly because the larger magnets would end up having the heating wire pass directly over them and not sure they would enjoy that despite being rated for 150C.
Used "704" to tack down the heating wire, clamping each row down to try and get a good thermal bond, covered it all with high temperature silicone, a layer 2mm ceramic wool and a sandwich of silicone, fiberglass and aluminium foil. Will see how durable it ends up being. Also put a 120C thermostat, a 150C thermal fuse and PE bond on it, hopefully that takes care of the health and safety checkboxes:)
6 minutes and some change to 20 to 100C, phone died while recording so not quite sure.
Did you check out our Kickstarter? We are offering 150º C magnet and PEI coated spring steel; might be a perfect fit for your bed!