This is a simple and fast way to level your build platform. I will not promise it is safe, but I have been printing this way for a couple of weeks and have had NO problems.This also helps insulate your build platform. I don't know how useful that is to other people, but it helps me a lot, as the build platform sometimes cannot reach temperature if I have the fan going and the window open. The big gap beneath the board just lets the air suck the heat right out of the platform. This solves that problem 100%.It also provides a /little/ cushion in case you /do/ hit your build platform. But I wouldn't count on that to save you.The picture of the big gear is just there to prove that my platform is, indeed, level. The other pictures are a little misleading, since my camera is lousy and tends to introduce distortions. I had to abort that print partway through when I put my hand in the printer and screwed up the X+Y axis; yeah, that was dumb. I have not had to adjust it even a little bit since I started using this, which makes me believe the stuff is not prone to eventually compressing and dropping the platform -- or any other sorts of problems you might imagine.I think the pictures should make the technique pretty obvious. You just get a sheet of "ZOLTEK PYRON":http://www.zoltek.com/products/pyron.phpThis is easy to source at your local Home Depot (as this link may not work, it's an "OATEY" brand "FLAME PROTECTOR"):http://www.homedepot.com/h_d1/N-5yc1v/R-100345508/h_d2/ProductDisplay?storeId=10051&keyword=flame+protector&jspStoreDir=hdusΝ=P_PARENT_ID&navFlow=3&catalogId=10053&langId=-1&ddkey=SearchAnd also makes an excellent replacement for the ceramic tape in your MK5 hot end, should you find yourself needing to rebuild one. I've been running my with this stuff in it for about a month and it's flawless.Anyhow, just cut a square the appropriate size and take off your PCB, put this stuff under it, and put it back on... I didn't even cut holes out for the boltheads in the middle of the platform. It should be a pretty good squeeze, but you will not be afraid of cracking your PCB or anything, it's not that tight.Now just loosen your top nuts to level the build platform. It'll ride up to meet them as if it were on springs (which might not be such a bad idea, either...)Hopefully you can see in the photos how my platform is not resting on the lower nuts, but instead just pressed up against the top nuts by the sheet of PYRON.