Now got this thick motherf… Milled aluminiumheatbed with silicone heater. Wires are very thick and not that flexible but hey tonight iam working on it further. This is supposed to make even temperature and now bow itself when heated up.
Nice, where did you get it and what is the build area?
@Mark_Rehorst
Yes ive hoped it had the threepointmountingholes as well but you can set 3 screw the 4th on and check it. Works 
@Jeremiah_Coley ive got it from @Filafarm its 218x218 but they have allmost every possible dimensions with and without holes, with and wirhout threads and so on.
(http://www.filafarm.de)
machine p0rn!
I hope, the mounting-holes in the lower plate are big enough to give thermal expansion some room to wiggle Otherwise you are going to bend this flat plate into a curved plate
@Rene_Jurack thats true. Its mounted fixed without springs so this could happen. Havent got the longer screws for my springs yet…
Because you are doing silicone covers for your hotend, you can do silicone spacers for the heatbed aswell, like this: http://well-engineered.net/index.php/en/39-silicon-spacer-as-substitute-for-springs-beneath-the-printbed
@Rene_Jurack nice idea thx ill do that!
You should close the air gap between the heater and the bottom plate with ceramic wool or fire stove gasket (which is ceramic). That will help you heat up faster and keep corners to even heat.
Consider making it flippable. My Mic6 heat bed took a set and is slightly domed. Wish I could have flipped it over periodically.
@Jean-Francois_Talbot if you look closely youll see industrialgrade ceramic wool matt under the bed
@Robert_Swarner the test is to have a stable no-need-to-do-shit-heatbed. I mentioned in other threads that such a plate can warp but most say they dont. I had problems with mk3 heatbed and mk2 heatbed which i want to eliminate with this
@VolksTrieb cool, couldn’t see it well on my icraphone 
Yeah, I get it! What was my hope too. It could be mine was over-constrained, but I found some articles (I’ll try to find one and link here) from ceramics manufacturing where they used Mic6 slabs to heat parts from below. When the heat flux is always in the same direction through the plate, they take a domed set. I know @Brook_Drumm has had really good success with Mic6. Maybe, like I said, my flaw was with mounting. BTW, I did more or less what you’re planning, with four holes. Level with three, then set the fourth. If I make another, I’ll switch to three holes. Good luck!
@Robert_Swarner thanks for the comment yes I hope I have luck this time
@VolksTrieb thanks
Here’s one of the discussions I referred to: http://cr4.globalspec.com/thread/72500/Mic-6-Aluminun-Plate-Warping-Away-from-Hot-Plate
Looks good! My printer has a 18"sq. mic6 bed @ .390"" thick. 1200watt 120V silicone heater and no insulation under the bed. I can reach 70C in 2 minutes so you should be fine. A bed with this much mass will also hold heat very well. I have to wait for ten minutes after a print to remove the part.
@Kyle1 yes it does ive tested it this morning. Holds the heat waaaay better. Which is nice for holding the temp really constant