Hate warping and don't have a heated build platform‽ No worries, a few coins in perfboard will have you flat in no time.These are instructions for an UP!, but most tips should apply to a Cupcake too! YMMV.Taken from http://pp3dp.com/forum/viewtopic.php?f=3&t=96&start=10#p1792, here's all you need to know about warp-free printing on the cheap!"The perfboard trick is baller! Big UP!s rross! I haven't had any warping since I started printing on it and I'm going deep and wide and tall. Of course I've done the platform leveling and nozzle height adjustments, but until I printed on perfboard, I'd get some warping on wide, long or thick prints. If you can't find copper plated perfboard, no worries; it's the holes, not the copper, that does the trick.A few tips if you decide to do this:Obtain Verboard or 0.1" fiberglass perfboard and cut to size at an angle. Semi-copper plated perfboard works best but the flatness is achieved mechanically, so don't sweat if you can't find the copper stuff.